BULLETIN
of the

FLORIDA STATE MUSEUM
Biological Sciences

Volume 32 1988 Number 2

RESOURCE PARTITIONING IN A COMMUNITY OF
PHILIPPINE SKINKS (SAURIA: SCINCIDAE)

Walter and Troy Auffenberg

e
UNIVERSITY OF FLORIDA GAINESVILLE



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RESOURCE PARTITIONING

IN A COMMUNITY OF PHILIPPINE SKINKS

(SAURIA: SCINCIDAE)

Walter and Troy Auffenberg*

ABSTRACT

Eleven species of variously sympatric species of skinks were studied in southern Luzon,

Philippines. In snout-vent length these species varied from 27 to 117 mm. Species diversity

was found to be positively correlated with vegetation density.
The food analyses were based on a total of 2481 adult specimens collected in monthly

samples of about 30 individuals of each species for a period of one year. Excised stomachs

contained 10,739 food items. Food size, volume, and seasonal representation were stressed in

the analyses of each species. Additionally, seasonal insect abundance data were obtained for

all of the major microhabitats of the lizard species. Annual abdominal fat accumulation and

degradation cycles were investigated in all species.
We found almost no evidence of food niche partitioning in most species investigated;

exceptions were species that lived in unusual environments (arboreal, semiaquatic, marine
Iittoral) inhabited by single species. However, food selection may be playing a role in the

distribution of some terrestrial species living in close contact on the floor of local moist
evergreen forests. There is no clear basis for suggesting that prey were selected on the basis

of nutritional value. Nor was there a significant correlation between predator and prey size or

volume-partly because several species frequently fed on inordinately large prey.
Seasonal switching of prey types was common among almost all the species. The only

exceptions were those that lived in very stable environments, such as the marine littoral. In

all instances, such switching could be shown to be directly related to local insect abundances.

*Walter Auffenberg is Curator of Herpetology, Florida State Museum,University of Florida,

Gainesville FL 32611; his son Troy is an undergraduate student at the University of Florida,

Gainesville FL 32611.

AUFFENBERG, W., and T. AUFFENBERG. 1988. Resource partitioning in a community of

sympatric Philippine skinks (Sauria: Scincidae). Bull. Florida State Mus., Biol. Sci. 32(2):151-

219.



152 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

Only about half of the local skinks possess abdominal fat at any time of the year. Of
those that do, the annual accumulation and degradation cycle is similar in both males and
females. In every species examined the cycle can be shown to be linked to seasonal insect
abundance.

The Caramoan Peninsula of southern Luzon contains a number of habitats, and no
species of skink ranges through all of them. The local forest is richest in number of species,
and this is believed due to its greater structural complexity. Among species inhabiting similar
habitats there is significant ecological replacement, both horizontally as well as vertically.

RESUMEN

Se han estudiado once especies de esquincos (Scincidae) en el sur de Luz6n, Filipinas.
Estas especies se encuentran simpatricas en varias combinaciones y varian desde 27 a 117
nim de largo (hocico-ano). La diversidad de especies muestra una correlaci6n positiva con la
densidad de vegetaci6n.

Andlisis de alimento se basan en un total de 2481 ejemplares adultos recolectados en
muestras mensuales de aprox 30 individuos de cada especie for un afio. Los est6magos
analisados cotenian 10,739 unidades de alimento. Se han notado especialmente tamafio de
presa, volumen de alimento y representaci6n estacional en el andlisis de cada especie. A la
vez se han recolectado datos sobre abundancia estacional de insectos en todos Ios
microambientes principales de las especies de lagartija. Se estudiaron los ciclos anuales de
acumulaci6n y degradaci6n de sebo abdominal en todas las especies.

Casi no se encontr6 ninguna evidencia de separaci6n por nicho alimenticio en las
especies estudiadas, salvo en algunas especies de ambientes exceptionales (arb6reo,
semiacuatico, litoral marino) habitadas por especies unicas. Sinembargo, la selecci6n de
alimento puede jugar un papel en la distribuci6n de algunas especies terrestres que viven
contiguamente en el suelo de las selvas hlimedas siempreverdes. No hay base clara para
sugerir que escogen sus presas a base de valor nutricional. Tampoco hay una correlaci6n
significante entre predador y tamano o volumen de presa-en parte porque varias especies
capturan presas extraordinariamente grandes.

Cambios estacionales en el tipo de presa son frecuentes entre ca5i todas las especies.
Las unicas excepciones son Ias especies que habitan ambientes muy estables, como el litoral
marino. En todos los casos, estos cambios se relacionan directamente a la abundancia de
insectos en el ambiente.

Aproximadamente la mitad de los esquincos locales poseen sebo abdominal en alguna
6poca del afio. En los que si 10 muestran, el ciclo de acumulaci6n y degradaci6n es semejante
en machos y hembras. En cada especie estudiada el ciclo esta ligado a la abundancia
estacional de insectos.

La Peninsula de Caramoan del sur de Luz6n incluye varies ambientes, y ninguna
especie de esquinco se encuentra en todos ellos. La selva es el ambiente mas rico en numero
de especies, y creemos que esto se debe a su mayor complejidad estructuraL Entre las



AUFFENBERG AND AUFFENBERG: PHILIPPINE SI<INKS 153

especies que habitan ambientes parecidos hay reemplazo ecolagico, tanto horizontalmente
como verticalmente.

TABLE OF CONTENTS

Introduction 153
Acknowledgements 155
Method 155
Res,1 1 tq 159

Species Characteristics 159
Body Size Gradation Ratios 161
Species Diversity 164
Pattern of Habitat Differences 164
Temporal Patterns ' 166

Food 169
Abdominal Fat Bodies 190

Conclusion9 192
Literature ri,Pri 194
Tahip.q 198

INTRODUCTION

A major goal of our work was to obtain empirical quantitative data that
would help make the relatively specialized, yet morphologically homogeneous
scincids more useful in developing theories regarding lizard ecological and
reproductive niches and of lizard community structure in general. Whether
this group of generally cryptic and difficult-to-study lizards can be used to
accomplish this end remains to be seen. For many workers, iguanids have
proven to be attractive as research organisms. We hope to show that scincids,
representing a different set of niches, may also contribute substantially to a
rapidly growing body of herpeto-ecological knowledge at the community
level--a point repeatedly stressed in more recent papers, such as those of
Barbault (1974a, b). The present study is the first of a two-part series on a
skink community in tropical evergreen forests of the Philippines and stresses
food niches.

Lizard Niches.-- During the past two decades a number of studies
provided herpetologists with many important data on the ecological niches of
lizards. Most of these have concerned members of the families Teiidae,
Agamidae, Lacertidae, and Iguanidae. The family Scincidae has received less



154 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

attention--particularly the tropical species. Most studies published on
scincids are of single species; only a few compare sympatric forms or analyze
niche dimensions and resource partitioning; none has explored broader
patterns governing the structure of scincid assemblages in areas where they
dominate the local lizard fauna. With the exception of those by Alcala (1966),
no studies have been published on Philippine scincid ecology or reproductive
biology. Though a few recent publications have concerned lizard trophic
relations (several of which have explored both food and place niches), none
has dealt with Asian specie5.

In the current study, the authors examine aspects of the feeding biology
of 11 geographically sympatric species in southern Luzon, Philippines, that
bear on the following questions: (1) What dimensions of the ecological niche
appear to be crucial and how strongly are resources (food and place)
partitioned? (2) Do quantitative measures of overlap among paired species
imply possible interspecific competition? and (3) In what ways do these
skinks vary in responses to annually changing environmental conditions, even
though the changes may be slight in this tropical area?

Food Habits.-- Because of their high visibility, abundance, and extensive
ecological radiation, iguanid lizards have also attracted the most attention of
ecologists interested in lizard foraging strategies, and most generalities are
based on those studies. However, it is questionable how widely these
generalities apply outside of the very specific conditions in which they were
conceived. No studies addressing these questions have yet been conducted
on scincids, and a primary goal of the present study was to test some of the
hypotheses regarding prey utilization patterns in non-iguanid insectivorous
lizards.

Most of the documentation of food niche partitioning in reptiles has
come from the studies of anoles on relatively small Lesser Antilles islands
(see Floyd and Jensen 1983 for review). These islands are characterized by
high density, simple lizard communities (1-2 species) and depauperate faunas
of potential competitors and predators. On such islands the competition
experienced by these lizards is perceived as intense and largely intrageneric,
the lizards being considered food-limited. In contrast, studies of lizard food
habits in Central and South American mainland sites have not found
evidence of food-niche partitioning (see Duellman 1978 for review), implying
that food competition is relatively unimportant in these ecologically more
complex communities. A strong ecological dichotomy is thus suggested
between less diverse island and more diverse mainland lizard communities.
Unfortunately, this is based on relatively few studies, and these within
restricted and distinctly divergent faunas.

In the Indo-Australian Archipelago the Family Scincidae is a very
diverse group, including many potential intrafamilial competitors of diverse
habits and residing in many different habitats, varying from some that parallel



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 155

those of small island communities to others that parallel those of diverse, rich
mainland forest habitats. The data we collected provides the opportunity to
(1) determine the pattern of food niche partitioning among scincids in
southern Luzon, (2) examine measured variables for possible food limitations,
and (3) look at the effect of seasonality upon the diet of a community of
scincids.

ACKNOWLEDGEMENTS

Thanks are extended to the Philippine government for allowing this study to be
conducted and to the citizens of the Caramoan Municipality for their cooperation during its
tenure. Mr. Steve Alba, Forest Development Office, Naga District, obtained much of the data
on densities and activity patterns of skinks. Finally, it is impossible to express the gratitude of
both authors to Elinor and Garth Auffenberg. Without their massive assistance throughout
all phases of the study in the field, the analyses and ideas expressed in the following pages
would not have been possible. We extend to them both our deep appreciation for the
countless hours they spent on behalf of the project.

- METHODS

Of the 11 skink species studied, 9 are the better represented : Emoia
atrocostata, Lamprolepis smaragdina, Brachymeles boulengeri, Mabuya
multifasciata, M. multicarinata, Sphenomorphus jagori, Lipinia pulchella,
Otosauna cumingii, and Tropidophoms grayi. For these species, 30 large
individuals were collected each month for a period of one year (July 1962-
August 1983) in the environments close to the field camp at the village of
Terogo, Caramoan Peninsula, Camarines Sur, southern Luzon, Philippines
(123 ' 51 'E , 13 ' 55 'N). Fewer individuals were obtained of Dasia grisia and
Brachymeles samarensis. Most individuals were collected by hand or sling
shot, though T. grayi and 0. cumingii were often caught by "angling" for them
with a baited hook lowered into their burrows.

The study area (ca 15 km2) is largely covered with limestone karst
mountains, with elevations ranging from sea level to 350 m. Most of the area
is clothed with mixed dipterocarp evergreen forest (Whitmore 1975), though
secondary forest is extensive, particularly near sea level. Agricultural lands
include abaca and coconut plantations, as well as terraced rice lands.
Mangrove forest, nipa palm swamp, rocky beaches, and headlands occur
along the coast. Details regarding the local vegetation, topography, and
climate are available in Auffenberg (in press).



156 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

Density estimates for those ecologically sympatric species in which they
are discussed were obtained along the marked transect of a small mountain
near the base camp at Terogo. The transect was covered in the same fashion
on a regular schedule every day (equal daily and hourly representation) over a
5-day period once each month during the entire study period. Climatic and
other data were collected during each traverse at eight stations selected to
reRect habitat variation in the local forest through which the transect ran. At
each station air temperatures were obtained at 10 cm above the surface and at
the surface. When lizards were seen, the following data were collected:
activity type when sighted (foraging, intraspecific interactions, or basking),
angle of sighting in respect to transect path, perpendicular distance between
lizard and transect path, elevational position of lizard (in meters above the
surface), general lizard size, date, and time of sighting. Technique and
analysis of density estimates follow those outlined by Burnham et al. (1980).

Individuals were also collected away from the transect area on a monthly
basis. These were immediately preserved and later measured (hereafter,
snout-vent length = SVL, total length = TO to the closest mm. An adequate
series of each was weighed immediately after death (but before preservation)
to the closest 0.1 g (= Wt hereafter).

The total number of individuals of each species examined for stomach
contents are : E atrocostata 318, L. smaragdina 358, B. samarensis 43. B.
boulengeri 350, M. multifasciata 318, M. multicarinata 353, D. grisia 61, S.
jagori 363, O. cumingii 305, T. grayi 368, and L. pulchella 355. Selected
individuals were used for other analyses and these totals are indicated in the
appropriate places.

Stomach contents were examined by excision and dissection. Data
obtained on insect prey found in the stomachs were category type (taxonomic
determination to family level) and individual prey length (to closest mm). We
recognized 40 prey categories based on both entire and partly digested items.
However, the latter were omitted from prey size and volume analyses unless
original sizes and volumes could be estimated.

Seasonal diurnal insect abundance was established by placing, once each
week for the entire year, four 10 x 15 cm sheets of a good quality flypaper at
each of seven stations near the base camp. These were left for an entire day
and collected in the late afternoon. The trapped insects then were
categorized by family and individuals in each category counted. Locations of
the seven stations overlapped part of the transect used for studying lizard
densities and activity patterns. All the microhabitats represented along the
transect were included in the seven stations used to determine insect
abundance and diversity.

In the following section terms used are defined, and where appropriate,
analytical techniques are outlined.



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 157

Coefficient of Community. This is a mathematical measure of the
relative similarity of samples from two communities (Whitaker 1970):

CC = Sat/(Sa+Sb-Sal))'

where Sab is the number of species shared by samples a and b, Sa is the total
number of species present in sample a, and S~ is the total number of species
in sample b.

Ecological Allopatry. Tko or more species living in the same habitat,
but separated by differences in microhabitat and/or diel activity period.

Ecological Sympatry. 'Iko or more species living in the same
microhabitat and overlapping in their diel activity period.

Microhabitat. In the Caramoan primary forest the following lizard
microhabitats are recognized: fossorial, leaf litter, ground surface, shrub layer,
low tree trunk, high tree trunk (and major branches), and canopy. In
agricultural lands the microhabitats recognized are fossorial, surface, and
coconut tree trunks.

Niche. Our usage follows that of Hutchinson (1957), being an abstract
concept of a multidimensional factor. The dimensions are physical factors
and biotic relationships necessary for the survival of the species.

Niche Breadth. Describes the spectrum of any given dimension of the
niche volume (see Pianka 1972),

Bi = 1/Sum pij2

where pijz is the proportion of individuals of species associated with resource
j. Standarized niche breadth values (Bs-) are obtained by dividing the niche
breadth value (B·) by the number of resource states.

Niche Over~ap. This is a measurement of the association of two or
more species with respect to some dimension of the niche hypervolume (see
Colwell and Futuyma 1971),

Cih = 1 1/2 Sj Pij - Phj'

where C is the amount of shared resource states between species i and h, p.· isN.the proportion of individuals of species i associated with resource j, and n is
the second species of the matrix. In this measure, C has a value of 0 when
species i and h share no resource states, and a maximum value of 1 when the
proportional values from two or more independent analyses of different
resources provides an overall niche overlap value. The overall values are
obtained by multiplying for each pair of species the total of the individual
niche overlap values, times 100 (= product alpha of Cody 1975).



158 BULLETIN FLORIDA STATE MUSEUMVOL. 32(2)

Resource Partitioning. The differential utilization of the physical
and/or biotic environment by different  species.

Shannon-Wiener Diversity Index (D). For the present application, this
index describes the average degree of uncertainty of predicting the number of
prey categories in a given lizard species. Two components of diversity are
combined in the index: (1) number of species, and (2) equitability, or
evenness of allotment of individuals among the prey species. A greater
number of prey categories increases species diversity, and a more equitable
distribution among prey categories will also increase diversity as measured by
this function. The formulas used are,

D = - Sum (pilog Pi),

where p. is the decimal fraction of the total individuals belonging to the ith
species, b is the information content of sample, i. e. index of diversity, and S
is the number of species (prey categories), and,

Dmax =-S (1/S log2 1/S),

where Dmax is the species diversity under conditions of maximal equitability
and S is the number of species in the community (prey categories in the
stomachs), and,

E = D/Dmax,

where E is equitability (range 0-1), D is the observed species diversity, and
Dmax is the maximum species diversity (= log2S)

In some instances Simpson's Index (B) is substituted if it is the
preferred statistic, where,

B = 1/Sum pil

where B is the diversity index ranging in value from 0 (low diversity) to a
maximum of 1-1/S.

Throughout the text, figures and tables, standard symbols are used for
the mean (X), sample size (N), standard error of the mean (SE), standard
deviation (SD), correlation coefficient (r) and Spearman rank correlation
coefficient (r~)·



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 159

RESULTS

Species Characteristics

Unless otherwise stated, the latest review of the taxonomy and
distribution of the skinks examined occurs in Brown and Alcala (1980).

Emoia atrocosmta (Lesson). This is a moderate-sized species of the
genus, with no Luzonyonspecifics. In the Caramoan-area females are larger
than males (p = 0.05, X ~L females 88.2 * 2.1 mm, X Wt 12.6 = 1.1 g, N=19;
males 84.2 * 3.3 mm, X Wt 10.9 g, N=60). Though widespread in the
Philippines, E atrocostata has a completely coastal distribution and is found
on rocky beaches, fish pond dikes, and rocky outcrops in mangrove swamps.
Alcala and Brown (1967) studied a population of this species on Negros
Island, Philippines.

Dasia gn'sia (Gray). A large member of the genus, with only one species
on Luzon. In the Caramoan ala the sexes are not significantly different in
either length or weight (adult X SVL 105.0 * 1.5 mm, X Wt 24.3 + 4.1 g,
N=23). It is widespread in the Philippines and previously has been reported
from Luzon, though considered uncommon. Brown and Alcala (1980)
reported finding specimens on rotting tree stumps and under loose bark in
forests from 100 to 200 m. Our specimens were collected from widely
scattered localities in the study area from as low as sea level to 250 m, but
always in relatively undisturbed forest.

Lamprolepis smamgdina philippinica (Mertens). This is a relatively large
species of the genus, with no conspecifics on Luzon. In the Caramoan area
the sexes are not significantly different. Brown and Alcala (1980) stated that
it is almost completely arboreal, being found in gardens, coconut and abaca
plantations, and dipterocarp and mangrove forests. Near Caramoan we
found it in all generally open situations, particularly in secondary growth and
coconut plantations, from sea level to 350 m (higher elsewhere, Brown and
Alcala 1980). It is one of the most common of the Caramoan lizards. Alcala
(1966) and Reyes (1957) studied a population on Negros Island, Philippines.

L<pinia pulchella pulchella Gray. This is a species of intermediate size
within the genus. Though one other species is said to occur on Luzon, we
found only this one at the study area. Hex the sexes were not significantly
different in either length or weight (adult X SVL 38.1 * 0.8 mm, X Wt 0.6 g,
N=106). It has been reported from most northern Philippine Islands south to
Leyte, including the Caramoan area. We found it common near the ground
on the exposed trunks of trees and on large boulders--particularly in primary
forest. Brown and Alcala (1980) found it from 300 to 1000 m; we extend this
to sea level in the Caramoan area.



160 BULLETIN FLORIDA SrATE MUSEUM VOL. 32(2)

Mabuya mulnfasciata multifasciata (Kuhl). This is a large species of the
genus, with no significant sexual difference in either length or weight. In the
Caramoan area this species is somewhat smaller than reported *ewhere in
the Philippine Islands *ult X SVL in study area 90.5 * 2.0 mm, X Wt 22.6 *
2.2 g, N=135; 109 mm X SVL on Negros Island, according to Alcala 1966).
The species is widespread over much of Southeast Asia and has previously
been reported from Luzon. Wherever it occurs, it is usually very common,
being found on the ground in open sunny places, especially field and forest
borders, and in secondary forests and abaca and coconut plantations. It hides
in heaps of vegetation and under logs, but also in tree holes close to the
ground and under loose bark. It has been reported from sea level to over
1200 m. Alcala (1966) and Reyes (1960) studied a population on Negros
Island, Philippines. TVo other species of the genus occur on Luzon.

Mabuya multicarinata borealis Brown and Alcala. This is a medium-
sized species of the genus, with no significant sexual differences in either

-

length or weight in the Caramoan area (adult X SVL 71.0 * 2.5 mm, X Wt
11.5 + 0.8 g, N=160). It is widely distributed in the central and northern parts
of the archipelago from sea level to 1200 m. At Caramoan it is common in
primary forest, but mainly in sunlit openings and along trails, occasionally in
secondary forest. In both habitats it is found under leaves, rocks, rotting logs,
or climbing about on stumps, tree trunks close to the ground, or on large
boulders. There are two congenerics on Luzon, but only one other species
locally.

Bmchymeles samarensis Brown. A small species of the genus, with
adults in the Caramoan area having a mean SVL of 60.7 * 2.3 mm, and a X
Wt of 1.9 * 0.6 g, N=43. Locally this species is found from sea level to 100 m,
under leaves, vegetation mats on logs and rocks, in rotten logs, in both
primary and secondary forests. It previously has been reported from
southeastern Luzon. Two other species are known from the same island, but
only one other congener occurs in the study area.

Brachymeles boulengen' boulengeri Taylor. A moderately large species of
the genus, with adult fEmales significantly longer than-males (p < 0.05, femak
X SVL 86.3 + 3.0 mm, X Wt 13.9 * 0.8 g, N=97; male X SVL 77.0 * 3.0 mm, X
Wt 11.0 * 1.0 g, N=90). It previously has been reported from Luzon. Locally
it is usually found under rotting logs, piles of vegetation (particularly leaves
and humus) in open situations (pastures, overgrown fields, secondary forests
and plantations of abaca and coconut). Brown and Alcala (1980) reported it
from 300 to 800 m, but we found it to nearly sea level (18 m). Two
conspecifics occur on Luzon, but only one other locally.

Sphenomo,phus jagori jagon' (Peters). A large member of the genus,
with a significant difference (p < 0.05) in length of adult males and females
overall X SVL 76.0 * 6.1 mm, NE62; adult females X SV6 75.0 * 5.1 mm, X
Wt 13.9 * 0.9 g, N=41; males X SVL 81.1 * 4.1 mm, X Wt 15.8 * 0.8 g,



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 161

N=121). The species is widely distributed in the archipelago and previously
has been reported from Luzon. Locally it is found in areas of primary forest
with a rocky substrate; rarely in secondary growth. It may be found under
leaves or logs, but is also seen actively clambering over boulders. Brown and
Alcala (1980) reported it as occurring from sea level to 1000 m.

Tropidophoms grayi Guenther. A relatively large member of the genus.
Local males and females are not significantly different in either SVL or Wt;
adult X SVL 94.1 * 8.1 mm, X Wt 18.9 * 4.8 g, 3=121. It is widely distributed
in the Philippines and previously has been reported from Luzon. Locally it is
mainly found in holes in banks along small streams (from where we "fished"
them with baited hooks). Taylor (1922) and Brown and Alcala (1980)
reported finding them under logs and rocks, where we also took them,
though less frequently. In the Caramoan area they occur from 80 to 350 m.
No congeners are found on Luzon.

Otosaums cumingii Gray. This is the largest species of skink in the
Philippine Islands. There is no significant difference in length or weight of
males and females from the Caramoan study area, in spite of the fact that the
mean SVL for females (121.1 f 15.9 mm) is greater than that for males (113.9
* 8.9 mm). Average Wt of adults is 41.1 g (N=63). Widely distributed in the
Philippines, this species previously has been reported from Luzon. Locally it
is found in rocks at the base of large boulders and cliffs, sometimes along the
steep banks of larger streams. Altitudinally it occurs from near sea level to
100 m locally, but probably extends higher into the hills in appropriate
habitats. No other species of the genus is known from Luzon.

Besides those species listed above, only one other scincid occurs in the
Caramoan District--Sphenomorphus steerei. It was captured too infrequently
during our study to include in the analysis. S steerei is a very small species (X
SVL 27 mm, N=4), seen from sea level to 150 m in secondary forest, usually
in leaf litter, but once high in the petiole axil of a coconut tree. Table 1
summarizes the meristic data for the Caramoan scincid species studied (see p.
198).

Body Size Gradation Ratios

Schoener (1968, 1970a, 197Ob) showed that the head and jaw sizes of
Anolis species are positively correlated with body size ; Caldwell (1973)
reported similar results in hylid frogs and concluded that body size ratios
between different species can be used to determine if a regular size
progression exists within the reptiles and amphibians of a single community.
Both authors ascribed these patterns to prey size and availability. Using SVL
ratios of differences between species (mean SVL of each species of



162 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

community/mean SVL of smallest species in community), Duellman (1978)
found no size groupings, either taxonomic or ecologic in frog and lizard
communities of his Ecuadorian study site. Rather, there was a steady
increase in SVL from the smallest to the largest Anolis species in the
environment studied.

Table 2 shows that among the skinks of the Caramoan area, the ratios of
differences in SVL's of skinks arranged in a size series is also an even
progression, with the ratios ranging from 1.41 to 4.33. This is a significantly
greater order of magnitude than demonstrated in Duellman's analysis of
Anolis body size in South American forests (1.01-1.46). Thus on the basis of
range in body size of the constituent species, the Caramoan skink community
is presumably predating a significantly greater range in prey size.

1

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S

-

BODY SIZE

Figure 1. General relationship of scincid body size to body size ratio (Otosaurus cumingii
used as standard against which all others compared) in Caramoan skink species.



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 163

The incremental increase in body size from smaller to larger in any pair
of species in Table 2 varies from 1 to 36 percent. The greatest size differences
occur among the smallest local species. Interestingly, there are , no local
agamids that are size equivalents of the smallest local skinks (Fig. 1).
However, several local agamids and both varanids are significantly larger than
the largest skinks. Half of the local skinks are only from 1 to 5 percent larger
than the closest-sized skink species (71 to 94 mm SVL; S. jagon; B. boulengen,
E. atrocosmta, M. mulnfasciata. L. smaragdina and T. grayi). The species pair
closest to sharing the same microhabitat (M. muMcarinata and S. jagon) are
however rather close in mean SVL (ca 4% difference). While the overall
pattern is not that predicted by the work of either Schoener or Caldwell, the
pattern is clearly not fortuitous.

When the data on Caramoan skink sizes are compared as ratios of
SVL's between adjacent species, these ratios vary from 1.0 to 1.6, with a mean
of 1.2, SD 0.2. The low value for the latter suggests the presence of a regular,
incremental increase within the entire size series from each smaller species to
each larger one. Such sequential ratios within closely related organisms in
local communities have been described previously. Hutchinson (1959) showed
that in sequences of presumably competing organisms, average individuals in
successive species have weight ratios about 2, or ratios of 1.3 between typical
linear dimensions of successive species. This is nearly identical to the mean
value 4btained for the Caramoan series. Later studies on different vertebrate
and invertebrate organisms have shown that differences of 1.3 in a sequential
series is a common ratio among similar animals living in the same habitat
(Uetz 1977, and others). Food sizes of such organims also have been shown
to differ by the same sequential factor (Horn and May 1977). All these data
suggest that this empirical relationship is of some fundamental biological
importance, though admitted to be poorly understood.

However, that this ratio may have little or no biological importance in
regard to possible competition between community members is suggested by
the observations of Horn and May (1977). They show that the same ratio
occurs in ensembles of musical instruments that are often played together,
whereas instruments traditionally used in solos lack this incremental
progression. They also demonstrate that the same ratio applies to the sizes of
iron skillets and tricycle wheels. They conclude that the 1.3 rule may derive
from generalities about assembling sets of things rather than from any
biological peculiarity. We agree and believe that size distributions in
Caramoan skinks is more related to local community structure (including the
size and density of available prey, species packing, and the complexity of the
local biotic environment) than it is to any presumed competition between
them.



164 BULLETIN FLORIDA SrATE MUSEUM VOL. 32(2)

Species Diversity

Within the 11-species scincid lizard biocenose studied, several different
levels of species combinations are found. The only single-species skink
community is on the marine littoral, especially on beaches. Here only Emoia
atrocosmta occurs. Where the littoral is a mangrove association, especially if
rocky, the skink community may be a two-species one, withA. atrocostata and
Dasia gn'sia occurring together. Two-species skink communities are
represented by still other combinations. Thus Otosaurus cumingii occurs in
ecotonal and open forests with Mabuya mulnfasciata or with (separately)
Mabuya multicarinata. Tropidophorus grayi is rather restricted ecologically
when compared to many other local species, but in rocky stream side
situations it is sometimes found with M. multicarinata and/or Sphenomorphus
jagori. A three-species scincid community occurs only in secondary forests
and plantation-type vegetation (most often coconut). This assemblage is
comprised of M. multifasciata, Lamprolepis smaragdina, and Brachymeles
boulengeri. The greatest diversity in skink communities is found in primary
forest (locally of mixed lowland dipterocafp type), where the following six-
species community occurs: Brachymeles samarensis, M. multicarinata, S.
jagori, S. steerei (rare), Dasia grisia, and Lipinia pulchella.

Skink species diversity was computed by means of Shannon's Diversity
Index and these results were then plotted against density of trees greater than
10 cm DBH. Skink diversity is positively correlated (r = 0.81, p < 0.01) with
tree density (= vegetation complexity) in the local forests.

Pattern of Habitat Differences

To interpret adequately the scincid fauna of our study area it was
necessary to examine the ecological distribution of the species within the area.
Figure 2 shows that almost all the species studied are restricted to rather
distinct microhabitats, with little overlap between them. Lamprolepis
smaragdina is characteristically found in open habitats with scattered trees,
and within this habitat it is found on tree trunks and shrubs from near the
ground surface to 25 m high (X 2.7 m). Dasia grisia occurs only in densely
forested situations, on tree trunks and larger limbs (including mangroves)
from 3 to 25 m high (X 5.3 m, sample probably biased towards the lower parts
of the tree due to collecting methods). Lipinia pulchella is found in the same
habitat, but is restricted to a lower stratum within the environment, being
found on rocky outcrops and tree trunks from near the surface to about 3 m



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 165

DASIAGRISIA~~JI

UPINIA PULCHELLA~ <

OTOSAURUS CUMINGI ~,~SPHENO-6R~HUS JAGORT~ ~

TROPIDOPHOAUS GRAY:
LAMPROLEPIS SMARABDINA 7 6~~~- MABUYA MULTICAMINATA

BRACHYMELES SAMARENSIS

M  MULTIFASCIATA

BRACHYMELES·BOULENGERI

BEACH OPEN FOREST DENSE FOREST

Figure 2. General habitats of common skink species in the Caramoan area.

above it (X 1.5 m). Thus there are three arboreal skinks in the Caramoan
area, and none is ecologically overlapping from the standpoint of
microhabitats. Within the same general size class there are three other local
arboreal lizards--all agamids. These are Calotes marmoratus (shrub species),
Draco volans (trunk species of more open situations), and Goniocephalus
sophiae (a tree canopy species of dense forests).

Two local scincids are fossorial, though each is found in slightly different
situations. Brachymeles boulengeri is most common in open areas, where it
burrows under grass tussocks and surface debris (piles of dead vegetation,
household trash, and logs). B. samarensis is more common in forests and
along their edges. Here it burrows under leaf litter and root mats covering
logs and rocks. There are no other fossorial lizards in the immediate area,
though three different-sized species of typhlopid snakes are locally common.

The most diverse scincid group is that composed of the surface forms.
Some of these occur in restricted and special habitats, while others are found
throughout a rather broad ecological spectrum. In the Caramoan area,
Emoia atrocostata is an almost exclusive inhabitant of sandy beaches with
rocky outcrops; occasionally it is found on dikes and rocky outcrops in
mangrove and nipa swamps. Tropidophoms grayi is primarily found in crevices
and burrows in clayey or rocky banks and flood plains of small mountain



166 BULLETIN FLORIDA SrATE MUSEUM VOL. 32(2)

streams in dipterocarp forests. No other local lizard utilizes this microhabitat
as regularly. Otosaums cumingii is found in forest ecotones, on the flood
plain of larger streams, and in secondary forests. It is not found in primary
forest. In all these situations it is most common in sites with abrupt changes
in surface topography, such as near banks and cliffs. Here it spends
considerable time in crevices and holes.

Because the remaining three scincid species studied (Sphenomo,phus
jagori, Mabuya multifasciata and M. multicarinata) are often found in the
same general area and under similar conditions, more detailed study of these
species was conducted. This included gathering data on their density, diel
activity patterns, and microecological distributions along a 346 m transect
established near the base camp (see Methods and Fig. 3).

Table 3 shows the use of different environments by these three similar
species. While M. mult*sciata is the only terrestrial species in open local
habitats, it is most common in ecotonal situations. The two remaining species
are significantly more abundant in densely forested situations. However,
within these lower illumination habitats, M. multicarinata occurs in forested
situations in which the lowest vegetation stratum is more dense, often with
scattered boulders in the Caramoan area. While found in this microhabitat,
S. jagori is more common in open, rocky situations, including sloping (but
usually not vertical) rock faces. M. multicatinam and S. jagod are separated
further by their vertical distribution within the lowest forest stratum. Thus
only one of the 34 S. jagod found along the transect was above the forest
ground surface (at a height of 1 m, on a fallen log resting against a rock face).
Though M. multicarinam usually forages on the ground, it regularly climbs to
at least 4 m above it (surface 58%, to 1 m 21%, 1-2 m 18.4%, and 2-4 m
2.6%).

Table 4 shows the relationship between mature size (SVL) and habitat
preference. From it (when S. steerei is additionally considered) one concludes
that on Luzon tropical forests have the same number of skink species than
more open forests. However, the forest species are*gnificantly smaller (X
63.2, SD 21.7) than those in more open situations (X 93.4, SD 13.8; means
significantly different when S. steerei included; p < 0.02, t = 3.37, df = 9).
There is also less size variation among forest skinks than among those living
in more open environments.

Temporal Patterns

All the terrestrial and arboreal skinks of the Caramoan area forage only
during daylight hours. There is, however, evidence that, at least in captivity,
Tropidophorus grayi sometimes feeds during the night. Data on diel activity



BEZ>-: CA -J~-
* TRANSECT 346 M *

AUFFENBERG
 AND AUFFENBERG

: 
PHILIPPINE SKINKS  

167

S. JAGORI
A e

.

A /I 40. I M. MULTICARINATA

.*je .. . . e ':... 0

..

~4 0_ 0 0446 *00-0
. M. MULTIFASCIATA . 0 0 0

...4 4. e . :5f; :.:0: I .. .....P..

Figure 3. Spatial distribution of three ecologically similar skink species along a forest transect (see text)



168 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

periods were obtained only for the three terrestrial species inhabiting
generally similar microhabitat (i .e . M. multifasciata, M. multicarinata, and S.
jagon). All three are active about 25 percent of the total daylight hours
available to them at this latitude (M multifasciata 22%, M. multicarinata
21%, and S. jagori 21%; values not significantly different than expected).
However, the way in which they allocate their time during the day is different.
In general, the daily pattern of S. jagon' is more distinctly bimodal than the
other two (Fig. 4), which tend to be active throughout the day. In all three
species, basking is the most common behavior early in the day and occurs
most between 0800 and 0900 hr. During the following hour there is a peak in
social activity. M. muinfasciata and S. jagori intersperse this morning
socializing with foraging, while M. multican'nam feeds rather regularly
throughout the middle of the day; basking is also a common behavior at the
same time, but with most of it shifted later in the day. M. mult<fasciata feed
primarily in the heat of the day (Fig. 4) from 1300 to 1400 hr. All three
species show a decided late afternoon peak in social activity, and this tends to
be the last behavior of the day for all three species. It is particularly
significant that the behavior of M. multicarinata and S. jagori are so very
different in both basking and foraging, in spite of the fact that they both occur
in the same forest type, with similar surface temperatures and humidities
(Figs. 5,6), albeit slightly different surface textures. Whitford (1978) has
demonstrated that temporal partitioning in narrowly sympatric species is an
important factor in species packing in ant communities. It may also be
important among the more narrowly sympatric terrestrial species of the local
evergreen tropical forest. However, the degree of asynchrony in temporal
partitioning may not be a reliable index of competition via dietary overlap

Though asynchrony in time of activity is often used as an indication of
dietary or spatial competition, there is little verified justification for doing so
on the basis of studies of lizards in the field. Pianka et al. (1979) suggest that
rapidly renewed prey (as apparently occurs in tropical forest termite
communities of the leaf litter) could suffice as an alternative explanation for
reduced exploitative competition. In spite of the appeal of food competition
as a major driving factor in bringing about temporal separation of activity
patterns, many data suggest that this is not an important factor. Thus, the
diets of closely related nocturnal and diurnal organisms are often surprisingly
similar. One of the dearest cases of this is the work of Jasic' et al. (1981),
comparing the diets of diurnal and nocturnal vertebrates in Chile. They
concluded that temporal asynchrony in hunting does not always result in
lowered dietary overlap. Thus the different temporal activity patterns of
Mabuya multicarinata and Sphenomorphus jagori does not necessarily suggest
that they are competing for prey.



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 169

40 ·

20

0 . 1 0

20

40 · _ ~

%
 O

F 
TO

TA
L 

TI
M

E

0 ,

. I-Ii-IJLLLLLLLLLLLLLL lili-Ill
20 -

-

40

20

lilill'llilll'-1 - lili----ITTTTTTTFFEOUO1ZFIIIII9L___=1 'Ell'
7 8 9 10 11 12 13 14 15 16 17 18 19

TIME

Figure 4. Daily allocation of basking (solid), foraging (lined), and social (open) behaviors in
three ecologically similar skink species.

Food

One of the goals of this study is to determine the patterns of food niche
partitioning among skinks in a tropical evergreen forest. To do so we
examine each measured variable for possible limitations, and finally ask the
question, "What are the effects of seasonality upon the diets of these different
scincids?".

Food Type.-- Of the Caramoan skinks examined, 58-81% contained food
remains (Table 5). A total of 10,739 food items was taken from the 2,093



170 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

32 -

·. r-->
30 , »

. I-

28 · 4. 1

R
H
 (

%
)  

T 
(C

°) \

26 · /
GRASS

24 · ' OPEN STREAM BANK

ROCKY FOREST

0
7 8 9 10 11 12 13 14 15 16 17 18 19

TIME

Figure 5. Annual mean daily shade temperatures (10 cm above surface) in the major
microhabitats of three ecologically similar skink species.

100 - GRASS

OPEN STREAM BANK
90 · "L ROCKY FOREST\\

H.80 · :X:- - --:

:\\. r
70 ·

-1
60 ·

0
7 8 9 10 11 12 13 14 15 16 17 18 19

TIME

Figure 6. Annual mean daily relative humidity in the major microhabitats of three
ecologically similar skink species.



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 171

specimens with food in their stomachs. The distribution of food categories is
shown in Table 6. Ninety percent of all food items found are arthropods. Of
the 17 arthropod orders represented, 7 constitute the vast bulk of the prey
(Isoptera, Coleoptera, Orthoptera, Lei)idoptera, Hymenoptera, Araneida,
and Diptera, Table 6). Molluscs (including their eggs) are the next common
item (0.7%), followed by fruits (0.4%). Chordates are among the prey types
eaten rarely. They are represented primarily by lizards and snakes (0.3 and
0.1% respectively, including the eggs of both). Fishes comprise 0.1 %; frogs
and birds occur only once and twice respectively in the entire sample.
Annelids are also rare items.

Table 7 shows that termites are the primary to tertiary food category of
almost all species of scincids in the Caramoan area. There is no rank order
correlation between termite feeding and habitat or lizard body size. The only
exceptions are Otosaums cumingii (the largest skink in the area) and
Lamprolepis smaragdina, which lives in rather open situations on exposed tree
trunks, where termites are less common. However, even in the marine littoral
zone, Emoia atrocostata feeds on many termites. Pianka (1969) found that
termites are also the primary food of lizards in desert communities in
Australia.

Crustacea are eaten by most of the skinks studied, though almost all are
members of the Isopoda, commonly found in leaf litter. In most species,
crustacean-feeding is not common. The outstanding exception is the marine
littoral Emoia atrocostata, which feeds extensively on both isopods and
decapods (Alcala and Brown 1967 and this paper). Many of the latter are
larval forms and are apparently exhumed from the beach sand. Other skink
species living on tropical beaches in other parts of the world are also known
to feed extensively on littoral amphipods and decapods (Australia, Cogger et
al. 1983; Indonesia, Auffenberg 1980; East Africa, Canaris and Murphy 1965;
United States, Mount 1963).

Ants (Formicidae) are frequently the major food of arboreal lizards in
the New World tropics (Schoener 1969, Duellman 1978) and constitute the
only food of the arboreal agamid Draco volans in the Caramoan area (and in
study by Alcala 1966 on Negros Island, Philippines). Among the local skinks
only the two arboreal species of dense forests, Lipinia pulcheUa and Dasia
gn sia, regularly eat ants. The arboreal species of more open situations,
Lamprolepis smaragdina, eats relatively few ants. None of the local terrestrial
species eat many ants--nor do the fossorial species. There are only a few
species of terrestrial frogs locally and no terrestrial agamids in the Caramoan
area, and one wonders who then feeds on ants in the Philippine primary
forests.

Fishes (unidentified) were found only once in Emoia atrocosmm, but
more commonly in Tropidophoms gmyi. A terrestrial frog (Plaomantis sp,



172 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

found in the same microhabitat) occurred in the stomach of one
Sphenomorphus jagori.

Lizard remains were found in the stomachs of 8 of the 11 skink species
examined, proving that they are eaten by most of the local scincids. Most
lizard prey consisted of entire individuals of several of the local gecko species.
Reyes (1957, 1960) has reported that two species of skinks on Negros Island,
Philippines also occasionally eat geckos. In the Caramoan area , Hemidactylus
sp. and Cyrtodactylus monarchus were occasionally eaten by Mabuya
multifasciata, Emoia atrocostata, Sphenomorphus jagori, and Tropidophorus
grayi. Hemidactylus sp. and Mabuya sp. were found in a few Lamprolepis
snlamgdina. In this same predator species some tails (only) were found with
scalation matching that of L. smaragdina, but in every case the tail was too
digested to be absolutely certain of the identification. Almost all of the
Brachymeles boulengeri collected at Caramoan had regenerated tails. Though
such loss is often explained as resulting from predation, very little data exists
that supports this contention. Some tail loss in lizards may, of course, be due
to intraspecific agonistic encounters. Carr (1940) reported that tails of
Leilopisma laterale found in the stomachs of Florida skinks sometimes match
the part missing from the tail of the same individual, suggesting that
autophagy is possible. In the Caramoan study, alllizard remains found in the
stomachs of Brachymeles boulengeri are tails (only) of conspecifics, but clearly
not of the same individual, for they all possessed tails. Thus individuals of
this species are eating one another's tails. We assume that they snap these off
conspecifics as they make contact during movements just below the soil
surface and in leaf litter. B. boulenged also eats snakes, but these are also
fossorial types (Ramphorhynchus bmminus and 7*hlops manilae). Reyes
( 1960) is of the opinion that Mabuya multifasciata may eat conspecific young
on Negros Island.

Leaves and other plant debris were sometimes found in the gut, but in
all cases these seem accidentally ingested. However, fruits, often complete,
were found in 7 of the 11 skink species examined, showing that they represent
part of the food spectrum of most local scincids. This proportion is high
when compared with the food of skinks in other parts of the world, suggesting
that frugivory is probably more common among Asian forest-dwelling skinks
than in skinks from other areas (Greene !982 has already suggested that
herbivory is probably more common among small lizards than presently
assumed). Fruits are most commonly found in the larger arboreal species
Dasia gnsia and Lamprolepis smaragdina, where they represent 6.5 and 11.6%
of the total diet respectively. That diets may be remarkably different for some
species in different habitats is suggested by the food data of L smaragdina on
Negros, where no fruits are taken (Reyes 1957). In the Caramoan area,
Sphenomotphus jagod also regularly eat fruits (1%), which are apparently
found on the ground. The only local skink species in which fruits are never



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 173

2
B. b.

1

0

3

2

S
P

E
C

IE
S
 D

IV
E

R
S

IT
Y
 (

H
)

M. m.
1-

0

3-

2
L. s.

1-

o . .0,0.0, , BRM"Z"/adism

JFMAMJJASOND

Figure 7. Distribution of monthly Shannon-Wiener Diversity Indices for prey categories
taken by three skinks of open forest and inhabiting different microhabitats. B. b.,
Brachymeles boulengeri; M. m., Mabuya multifasciata; L. s., Lamprolepis smaragdina. Arrows
show months of high (arrow up) and low (arrow down) insect abundance in same area.
Cross-hatched sections represent periods of high rainfall.



174 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

3

2.

 --I
1 - S. j.

L-r-
·'··'•••'

3

2

S
P

E
C

IE
S
 D

IV
E

R
S

IT
Y
 (

H
)

1 
M. m.

'···.·

3-

2

1 L. p.

0
JFMAMJJASOND

Figure 8. Distribution of monthly Shannon-Wiener Diversity Indices for prey categories
taken by three skinks of dense forest and inhabiting different microhabitats. S. j.,
Sphenomorphus iagori; M. m., Mabuya multicarinata; and L. p., Livinia DUlchella. Arrows and
cross hatching as in Figure 7.



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 175

found are Emoia atrocostam (marine littoral), Brachymeles boulengen' and B.
samarensis (both fossorial), and Mabuya mumcannam (terrestrial forest
species). The absence of fruits in the latter is surprising, because all other
local terrestrial skinks eat them and because this species often climbs in low
shrubs.

At least six different fruit species are eaten by the Caramoan skink
community. However, because of the difficulty of identifying poorly known
small tropical forest fruits, none can be precisely determined.

Food Diversity Indices.-- The prey category diversity indices for the local
skinks represent two basic patterns. The more common one is seasonally
variable, with distinct high and low peaks (Figs. 7,8). The second pattern,
found in only Emoia atrocosmta and Lipinia pulcheUa, shows little seasonal
variation in prey diversity. The pattern of the former is, however, different
from that of the latter in representing a consistently lower prey diversity
throughout the year. Both habitats (terrestrial marine littoral and arboreal
dense forests) are probably relatively stable when compared to the ones used
by the other skink species in the area. The differences in the two species
patterns are illustrated by the differences in the mean monthly prey diversity
values (mean monthly diversity indices for E atrocosmm 1.03 and for L.
pulcheUa 1.76).

Shannon-Wiener Diversity Indices for species representing the more
common annual pattern with notable high and low peaks show different
patterns among syntopic skink species. Figure 7 shows that within the local
open forests Bmchymeles boulengen' not only has a generally low prey diversity
index through the year, but that the monthly diversity index for prey
categories presents a very different pattern from particularly the arboreal
Lamprolepis smamgdina. Figure 8 shows the prey diversities of skinks living
in densely forested areas. Sphenomo,p/ms jagon' and Mabuya mult<fasciata
(both terrestrial) have very similar patterns, whereas the arboreal Lipinia
pulchella is different in respect to the monthly distribution of high and low
peaks.

In general, many of these patterns show a depression in diversity values
during the dry season and through part or all of the first monsoon. This is
not correlated with monthly overall insect abundances, for the premonsoon
period is characterized by having high insect numbers (see Figs. 7, 8, and 10).
Thus in general, the diets of these skinks are narrower when food supplies are
abundant, and broaden when food supplies are more limited. This is also
indicated by the data in Table 8. However, the diversity of insects available is
not always related to total overall insect abundance. In fact, though insects
are locally abundant preceding the first monsoon, they are not represented by
many orders--only a few making up the bulk of the masses of insects moving
at this time of year. Thus the low diversity of insects in nature during the
premonsoon season is reflected in the low diversity of prey in the stomachs.



176 BULLETIN FLORIDA SrATE MUSEUM VOL. 32(2)

-

- A ... . 0.A 0
A A A O 0 A 0 0

A .

LO
G1
0 
PC

A A T 0 0,

A A
0

0

0
0 1 2 3

SPECIES DIVERSITY (H)

Figure 9. Shannon-Wiener Diversity Indices for prey categories (H) plotted against the log
of prey categories in skink stomachs per monthly samples. Triangles, Brachymeles
boulengeri; solid dots, Mabuya multifasciata; and hollow squares I.amprolepis smaragdina.

We must therefore conclude that prey diversity in nature determines the level
of prey diversity in the stomachs. There is no strong evidence for selection of
prey types other than in the proportion which these types occur in nature at
the same time of year.

Our analyses show that the total number of prey categories per predator
species per month varies from 1 to 13; Shannon-Wiener functions (H) ranged
from 0.16 to 3.00, and equitability ratios from 0.12 to 1.00 (Table 8). A plot
of the Shannon-Wiener values against the logarithm of the number of prey
categories in each month per species (Fig. 9) shows that when the skinks of
the open forested situations are considered, the prey categories fall on a
logarithmic curve that is shifted to the Y axis in the fossorial Bmchymeles
boulengen' when compared to curves for the terrestrial Mabuya mulnfasciata
and Lamprolepis smamgdina. In more dense forest habitats, the arboreal
L(pim'a pulche#a exhibits a seasonal prey category diversity pattern that is
more uniform throughout the year than the patterns of other local species.

Food Location.-- The food eaten by the 11 scincid species studied
suggests that much of the prey of most local lizards are foraged from leaf
litter and similar small particle-sized surface debris. This is particularly true
of the terrestrial skink species studied. Thus, the foraging tactics of these
terrestrial Philippine forest species seem very similar to that of Eumeces



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 177

lan'ceps when searching for hidden prey, as studied by Vitt and Cooper (1986)
in forests of southeastern United States. Most species of scincids outside the
tropical forests probably fall into this category. However, even among the
Caramoan leaf litter foragers there is much searching for prey on herbs and
rocks. This is particularly true for lepidopteran prey (both larvae and adults),
odonates, dipterans, jumping spiders, winged termites during swarming
periods, and ants during mass movements on the forest floor. Prey found
commonly in the leaf litter, or at the interface of the soil and litter, are
isopods, termites, ants, some spiders, earthworms, blind snakes, centipedes,
and scorpions. On Negros Island, Reyes (1960) presented evidence for
occasional carrion feeding in M. multifasciata.

On the other hand, other local skinks find much of their food under the
surface of the soil. Emoia atrocostata feeds extensively on marine
crustaceans, most of which it finds by digging small holes in the sand; others
are found running across the surface. Both local species of the fossorial
Brachymeles are probably highly opportunistic and apparently find most of
their food just under or at the interface of the soil and the surface. Such prey
include termites, blind snakes, earthworms, centipedes, scorpions, and
beetles.

The local arboreal species (Lipinia pulcheUa, Dasia grisia, and
Lamprolepis smaragdina) find much of their prey by digging in pockets of leaf
debris collected in crevices and hollows on the trunks and branches.
However, all three predators also catch much prey on the bark or twigs. In
fact, L. smaragdina is one of the most active foragers of the local skinks. All
the arboreal species occasionally descend to the ground to forage; least of all
Dasia gdsia, which tends to live at the highest levels within the canopy of any
of the local skinks.

The semiaquatic Tropidophoms grayi forages in leaf litter on the edges of
small streams, as well as in the same substrate under a film of water.
Depending on moisture, prey obtained in plant litter are mainly termites,
ants, isopods, and some semiaquatic to aquatic crustaceans. Additionally, it
will sometimes forage for free-moving prey in shallow water, such as
freshwater shrimp and particularly small fishes. That they also will snap up
small invertebrates that enter the short burrows and the crevices in which
they are regularly found near the water-air interface is demonstrated by the
fact that we regularly caught them with small baited hooks lowered into their
hiding places.

All the skinks studied forage almost exclusively during daylight hours
(but see below). However, there is good evidence from among the forest
transect data that most individuals forage on the surface about 40 percent of
the days in a week.

Food Niche Breadth.-- On the basis that if over 40% of the food taken
represents a single category, the species is to be considered a food specialist



178 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

on that food type, seven scincid species can be so designated in the Caramoan
forests. Emoia atrocostam is the only one specializing on crustaceans
(61.7%). It is also the only species found in the marine littoral zone of this
area. The only scincid species specializing on beetles are both arboreal forms-
-Dasia grisia (48.6%) and Lamprolepis smamgdina (47.2%).

Most food specialization in Caramoan scincids involves termites. The
local termite specialists represent both terrestrial (M. mult~sciata 45.5%, M.
multicarinam 61.49, and S. jagod 80.7%) and fossorial species (B. boulengeri
70.8% and B. samarensis 80.7%), but almost all local skinks feed on them
from time to time. Standardized niche breadth for the Caramoan scincids is
shown in Table 9.

Food Niche Overlap.-- Of all the food categories taken by Caramoan
skinks, Isoptera, Crustacea, Coleoptera, Lepidoptera, and Orthoptera are the
most consistently common among the different species. Niche overlap values
between pairs of skink species and for eachof these major food categories are
shown in Tables 10 to 15.

For Isoptera prey, food niche overlap is relatively minor among all
species pairs (Table 10), varying from 0.0024 to 0.45. Species pairs showing
the least overlap are Sphenomo,phus jagon'-Lamprolepis smaragdina and
Brachymeles boulengeri-L. smaragdina. All these species live in very different
microhabitats. Species pairs with the greatest overlap are Mabuya
multifasciata-L. smaragdina and M. multifasciata-Emoia atrocostata. None of
these species shares the same microhabitat, though both M. mulnfasciata and
L. smaragdina live in rather open situations.

The data show that while many termites are eaten by local skinks, there
is relatively little overlap between skink species when termites are used as the
basis of the dietary comparison. In some cases where sympatric species do
eat large numbers of termites (i .e . M. multicarinata and S. jagori), foraging for
them occurs during different parts of the day. In both these species termites
are found by rooting through leaf litter. Although S. jagori, as a morning
feeder, would tend to disturb the termites and remove a small number, the
subterranean galleries are left undisturbed. Since the litter is in a shaded,
temperature-moderated environment, the termites probably reenter the litter
in a few hours (see Johnson and Whitford 1975). Thus, even if individual
home ranges of these two species do overlap in some areas and even if both
lizard species search for the same food, their foraging at different times of the
day, even in the same location, offers a tactic to harvest the obviously huge
numbers of termites found in these forests

Both these skinks occur in fairly high densities in the local forests. Since
their primary food is termites, one might expect considerable interspecific
competition between them for this resource. Such interactions are deemed
energetically expensive. We found very little evidence of agonistic behavior
among these skink species, due perhaps mainly to the fact that their daily



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 179

foraging patterns differed significantly. Furthermore, our transect studies
show that not every individual in the area was active every day (probably less
than half the days of each week, see above). These results are similar to those
of Creusere and Whitford (1982) for teiids, and to those of Simon and
Middendorf (1976) for iguanids. Considering a pattern of surface activity less
frequent than daily and the reduced and segregated diel activity patterns of
the two species, temporal partitioning is probably very important in these two
species

Niche overlap for coleopteran prey (Table 12) shows a different pattern.
When compared to the patterns discussed above, niche overlap for
coleopteran prey is, in general, greater among various species pairs; none of
the values is as low as those above. This shows that beetle prey are regularly
shared among these species. The lowest overlap value is found in the pair D.
gnsia-M. multicarinam. Both are found in forests, but one on the ground and
the other in the trees. In general , M multicarinata tends to have low overlap
values with many other Caramoan skinks, and particularly with L. smamgdina
(arboreal) and S. jagon. The latter is particularly interesting, for it is one of
the few cases in which food niche overlap can be considered as related to
possible food competition. The highest levels of overlap for coleopteran
foods are in the species pairs M. multican'nam-0. cumingii, T. grayi-0.
cumingii, and T. grayi-B. boulengeri. AR live in different microhabitats.

For lepidopteran prey the overlap is generally low (Table 13). The least
overlap is found in the pairs L. smaragdina-L. pulcheUa. Though both species
are arboreal (in different microhabitats), the former feeds on many
lepidopterans, and the latter on relatively few. Another low overlap pair is 0.
cumingii-E. atrocostam, where the latter feeds on very few lepidopterans in its
beach habitat, while the former feeds on a fair number in the forest in which
it lives. The greatest overlap is in the species pair E. atrocostata-M.
multicarinata. Both feed on few lepidopterans.

The pattern of orthopteran feeding among the caramoan skinks is rather
similar between species pairs, accounting for generally high overall values
(Table 14). The lowest overlap is found in the pair O. cumingii-E atrocostata.
The high values encountered in pair comparisons for orthopteran food are
among the highest recorded in the entire series of analyses. The arboreal L.
puldleila has remarkably high overlap with all skink species in the area,
regardless of skink SVL or habitat. The pair M. multifasciata-M.
multicarinata, and the former with L. smaragdina show high overlap values as
well. Although inhabiting different microhabitats, they are often found close
to one another spatially.

Table 15 shows the result of recalculating the same data, but combining
all these major food categories to illustrate overall food niche overlap. This
shows that of all the local skinks, S. jagori has the least overlap with other pair
members, and this overlap is least with M. multicarinata, and L. pulchella--



180 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

species found in the same general habitat (but also with L. smamgdina found
in more open situations). This suggests that food selection may play a role in
the distribution of these species in dense forest habitats. The greatest overlap
is seen between the pairs E atrocostata-L. pulcheUa, M. mult(fasciata-L.
smaragdina, E. atrocostata-M. multicarinata, and M. multifasciata-O. cumingii.
All these pairs are composed of species that live in totally different
environments, except the two species of Mabuya, which show some
intermixture along the forest edge.

Food Nutritional Value.-- None of the local invertebrates eaten by
skinks was analyzed for nutritional content. However, adequate data are
available in the literature for related prey types so that comparison and
discussion is possible. These data are provided in Table 16.

With the exception of the earthworms, the difference between the mean
water content of the various prey categories listed are not significantly
different. Ash is significantly higher in both earthworms and termites, due to
the fact that both these categories ingest much soil (Redford and Dorea
1984). In spite of the suggested differences in the means of percent nitrogen
and fat in some taxa, none of those important as skink prey is significantly
different at less than the 0.05 percent level; perhaps only because of small
sample size in some cases. The only important exception is that the mean
percentage fat of earthworms is significantly different than the means of all
other taxa (p varies from < 0.01 to < 0.001). Thus there seems little reason for
believing that these food categories represent significantly different
nutritional sources. There is thus no clear basis for suggesting that any of
these foods are qualitatively more nutritious than others.

Number of Food Items Per Stomach.-- Most Caramoan scincids have
from 2 to 4 food items per stomach. Only 6 percent of all stomachs were
empty, and there was no significant difference between skink species in this
regard. The following sequence lists the species in order of increasing mean
number of prey items per stomach (SD in parentheses): E atrocostata 1.2
(0.6), B. samarensis 4.5 (3.1), L smaragdina 2.0 (3.5), D. Fsia 2.3 (2.1), M.
mult<fasciata 2.6 (6.4), T. grayi 3.2 (12.9), L. pulchella 3.8 (11.7), M.
multicarinata 4.3 ( 15 .2), O. cuming# 4.4 ( 18 .5), S. jagon' 6.5 ( 19 . 1), and B.
boulengeri 9.0 (21.3). The mean number of items per stomach is negatively
related to mean prey size ingested. Additionally, those species with a greater
prey range also have more prey items per stomach.

Food Item Size.-- A total of 2672 prey items was measured (body
length). These data and the distribution of size classes among the skinks
studied are provided in Tables 17 and 18. They show that Brachymeles
boulengen' and Otosaums cumingii feed on the greatest range of prey size
(some prey are longer that the predators own body length). The least range
in prey size is found in the arboreal Dasia gn'sia. The mean prey length per
skink species ranges from about 4 to 17 mm (Tables 17 and 18). Standard



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 181

deviations of the means reflect the overall range of prey sizes eaten by each
skink species.

Many studies of lizard feeding have demonstrated a strong correlation
between prey and predator. body sizes. However, this relationship is not clear
in the present analysis (Table 18). Prey size is not correlated with lizard size
Crs = 0.43, Z = 1.35,p < 0.05)

The data relating mean SVL to mean prey size per species poorly fits an
exponential curve (Y = 4.23001X, R = 0.57). The non-correspondence results
largely from the tendency for the rather large B. boulenged to eat many
termites--small prey in proportion to predator SVL. In fact, were it not that
this species often feeds on blind snakes, the mean prey size would be much
smaller, further throwing this species out of what would otherwise be only a
fair fit. D. gnsia is another large skink that tends to feed on rather small prey.
The remainder fall within the 95% confidence level of the curve. Thus the
major exceptions are species living in somewhat extreme habitats (the most
fossorial and the most arboreal of those examined).

The overall difference in mean food particle size among skinks studied
(F = 8.63, p < 0.001) was partitioned into separate sums of squares for testing
the difference between pairs of skink species (Table 19). The results provide
an indication of the relative separation of species on the niche dimension
represented by food size. In this analysis, the magnitude of interspecific
differences does not depend on the correlation between food and body size.
A given difference in food size will reduce resource overlap and may enhance
co-existence, whether one skink species is either larger or smaller than the
second. Of the 55 pairwise contrasts, the pairs M. multifasciata-S. jagori, M.
multifasciata-B. boulengeri, L. pulchella-D. grisia, S. jagori-E. atrocostata, and
S. jagori-T. grayi are most similar in food size patterns. The pairs M.
multicarinata-O. cumingii, M. multicarinata-D. grisia, B. samarensis-O.
cumingii, and M. mumcadnam-L. pulchella are most dissimilar in food size
patterns. Each of the species comprising these species pairs, whether showing
the least or the most similarity in food size selection, are found in the same
habitat. The correlation may reflect the different feeding strategies of the
lizard species, but more likely reflect the distribution of insect prey in each
habitat.

Food Item Volume.-- Another way of evaluating the importance of food
in the total diet is to calculate the mean volume of prey acquired per prey
category. These data are provided in Table 20. These volumes vary from 0.4
to 198.0 mm~ for the smallest to largest prey types taken. Both mean and
maximum prey volume are significantly correlated with SVL in almost all
scincid species studied. The only important exception is Bmchymeles
boulengen, which feeds on many prey at both the very small and the large
ends of the total prey size spectrum. These data suggest that for almost all
species studied, lizard size is the major determinant of prey size, even though



182 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

all of the lizard species studied could eat larger prey, and some regularly did
(i.e. B. bmchymeles). Regression analysis Using lizard SVL and mean prey
volume for all the species studied results in only poor coefficients of
determination (Rb (0.014 to 0.182, p consistently greater than 0.05 in all
cases).

Table 20 also makes it clear that the two most important prey categories
eaten by local scincids from the standpoint of the total volume consumed, are
termites and orthopterans, representing 42.1 and 27.7 percent respectively of
the total food (in volume) eaten. No other prey categories come even close
to comprising as much. Together they represent almost 70% of the total
volume of food eaten by scincids in the Caramoan area. This is particularly
significant in the case of termites, for the mean volume of local termites is
only 7.2 mm3-a significantly small volume per food item when compared to
the total spectrum of item volumes regularly taken. It is the number of
termites taken, rather than their mass, that results in the high volumetric
total for this prey category. Several local lizard species specialize on termites,
which are represented by a diverse local fauna and a very common
constituent of particularly the floor ofopen and closed canopied forests.

Food Abundance.-- Diurnal insect abundance in the study area varies
seasonally (Fig. 10). In general, diurnal insects are least common from

32

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TO

TA
L 

T
O

TA
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A
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IN
S

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T
S

/M
O
 

P
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IP
./M

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P.

/M
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30

28

40 ·

20 ·

0 -

20 -

10 ·

0
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Figure 10. Monthly diurnal insect abundance (below), compared with total monthly
precipitation and mean monthly temperature for the Caramoan area.



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 183

November through April, and much more common from May through July
(with a dip in June). This pattern agrees fairly well with the rainfall pattern of
the same area. Other studies of seasonal abundance in tropical forests show
similar high peaks during early parts of the rainy season (Robinson and
Robinson 1970, Fogden 1972, Janzen 1973, Smythe 1974). In the Caramoan
area, the driest and wettest parts of the year have the least insects. The
greatest number is found in May, just before the first (summer) monsoon,
which occurs in July; August is a dry period between the two annual
monsoons, and from this month through the stronger winter monsoon
(September through January) insects become steadily less common. There is
no correlation between insect abundance and seasonal temperature (Fig. 10).

Eight different microhabitats were regularly sampled for the seasonal
abundance of diurnal insects (total insects trapped 4212, Table 21). These
microhabitats are the trunks of trees in the forest and the more dispersed
ones in the open, an overgrown field seasonally used for crops, a rocky
exposure in the same field, the edge of the field adjacent to the forest, leaf
litter in the primary forest, a rocky substrate in the same forest, and a series
of deep rock crevices in the same forest.

Of these microhabitats, insects were most abundant at the ecotone of
field and forest (Fig. 11)--the major habitat of Mabuya mult(fasciam. Insects
were also common in the overgrown field and rock outcrops in them (also
microhabitats of M. mult(fasciam, though less common there, perhaps
because of seasonal disturbance related to agriculture) and in the forest leaf
litter. The latter is the major microhabitat (with the forest-field ecotone) of
M multicarinam. Isolated trees in open situations have few insects when
compared to the situations listed above, but are the major microhabitats of L.
smaragdina. This is probably the major reason why Lamprolepis smaragdina
feeds on more fruit (11.6% of total diet) than any other local species (Table

6.2 (2.3)|
24.6 (2.9)

< 14.8 (9.2)
~ ~17.6 (5.4)11.5 (4.0)

18.4 (8.7)
Figure 11. Percent (S. D.) of total insects in different microhabitats sampled (see text),



184 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

7). Forest trees also have fewer insects than most terrestrial microhabitats,
but more than those inhabited by L. smamgdina. These forest trees are
inhabited by two species of arboreal skinks. Of these, the larger D. gnsia also
feeds on many fruits (6.5% of total food eaten). The rocky substrate of the
forest is the primary microhabitat of S. jagoriand contains relatively few
insects. This skink also feeds on more fruits (1.0%) than the remaining
terrestrial skink species living in microhabitats of greater insect abundance
(0.2-0.5%). Thus the extent of frugivory is related to the local prevalence of
diurnal insects. In genefal, insect prey provides considerably more protein
than fruits (see Auffenberg 1987 for details).

Lizard mean body size and insect abundance are not correlated in
different microhabitats examined. However, on the basis of the number of
lizards observed in different parts of the forest transect, the total number of
lizards per microhabitat and the average amount of insect food available in
each per month are almost perfectly correlated (r = 0.98). The relationship is
that of a simple linear regression and is expressed by the formula Y = 0.44 +
0.24X. The grassy field is the only microhabitat out of line in an otherwise
almost perfect positive regression. This is probably due to the fact that it is
the only unstable environment of those studied, due to seasonal agricultural
activity.

Mabuya mulnfasciam is the most common of the three terrestrial skinks
along the transect studied and is most common in that part of the transect
demonstrating the greatest insect abundance. M. multicarinam is found in all
of the microhabitats of the transect except grassy fields, and tends to be
associated with areas of moderate insect abundances. S. jagon' is the most
ecologically restricted of the three species and occurs in the microhabitat
having the least insect abundance.

On the basis of insect abundance in the different microhabitats at
different times of the year, the only microhabitat without seasonal insect
shortages is field edge, where M mulnfasciata is most common (Table 21).
The microhabitat of M. multicarinata (mainly leaf litter in shaded forest) also
has abundant food throughout the year, except for possibly April. The rocky
forest substrate on which S. jagori is most commonly found has
proportionately fewer insects throughout all the year, except during the first
monsoon (June through August). The same pattern applies to the forest
microhabitats of L. pulchella and D. grisia, both of which live in trees. While
insect food resources seem low throughout the year for L. smamgdina, the
potentially most stressful time for food seems to be during the dry season
preceding the first monsoon. Though insect food is also low in December
(probably due to the very heavy rain), L. smaragdina tends to be rather
inactive during that time of the year.

In general our conclusion is that, while some microhabitats support
more insect prey than others, there is in most of them a lower insect carrying



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 185

100%

0 M. mc

/E. a

DOR/4*4 M. mf. -\60

0 L. p.

D. g.

O. C

Ls/
0 100%

ISOPTERA

Figure 12. Summary of the utilization of the three most common prey categories eaten by
Caramoan scincids-Lepidoptera, Coleoptera, and Isoptera.

capacity in the dry season preceding the first monsoon (Fig. 10). If
competition for these resources is important, it is during this time of the year
when it is probably operative. There is no evidence that food is a major factor
in interspecific competition between these skink species in the local tropical
microhabitats during most, if any at all, months of the year. Additional
information and discussion regarding seasonal food use is provided below.

Figure 12 shows the trophic relations between the species of Caramoan
skinks in relation to the most common prey categories eaten. The illustration
makes it clear that most species concentrate on coleopteran and isopteran
prey; lepidopterans are not as common as these two categories. Terrestrial
dense forest species are the most important skink predators of isopterans,
and larger arboreal skinks the most important predators of beetles. Insofar
as they can be compared, the stomach content data of Reyes (1957, 1960) for
Lamprolepis smamgdina and Mabuya mulnfasciata on Negros Island,



186 BULLEnN FLORIDA STATE MUSEUM VOL. 32(2)

Philippines, are nearly identical to those from Caramoan for the same two
species, except that the relationship of lepidopteran to coleopteran prey is
reversed in L. smamgdina.

Seasonal Use of Food.-- Tables 22 and 23 provide data on the seasonal
use of the more important prey of Caramoan skinks. Several patterns
important in the feeding biology of this lizard community become apparent.
In spite of the fact one might assume that most taxa would be available
throughout the entire year in this tropical forest ecosystem, some prey are
taken on a strong seasonal basis. The clearest pattern is found in oligochaete
predation. These are taken during and particularly after the second
monsoon. This is the coolest time of the year (Fig. 10). None is eaten during
the warmer first monsoon. Mollusk feeding shows a similar pattern, though
less distinct. The surprising thing in this food category is that land snails of
all types are definitely very active and available during the first monsoon. The
fact that they are not eaten in quantity during the first monsoon suggests that
(1) mollusks are not preferred prey, and (2), when other prey types are
available these are eaten in preference to snails.

The pattern for termite predation is clearly related to rain. The main
utilization peak occurs during the early rains of the first monsoon, with a
smaller peak during the second monsoon. Termite activity has often been
shown to be related to rainfall patterns, and the utilization of termites by the
local skinks is probably simply a reflection of the seasonal activity patterns of
the termites on the ground. This is further suggested by the fact that over
90% of those termites eaten in May and June are alates, and that this is the
time when swarming is most common. Termites are the only prey eaten in
quantity during the earliest rains of the first monsoon.

Though eaten throughout the year, coleopterans are taken in greatest
quantity during and particularly after the second monsoon. This can be
related to the large number of seedlings and the new growth characteristic of
January and February, as well as the heavy fruit loads during October and
November (see Auffenberg 1987 for additional details). Fruit-eating also
follows the phenology of plants, for there are three distinct peaks in the
number of fruits found in the stomachs (March, July, and November-
December). Most of the lepidopterans taken as food represent the caterpillar
morph, and their abundance in the stomachs from February through April is
undoubtedly related to the considerable plant growth at this time of year.
Spiders are eaten throughout the year, though there are two peak periods.
One occurs from July to August and is correlated with the lepidopteran peak
of the same months; the second corresponds with the peaks in coleopteran
and orthopteran abundance during the second monsoon.

Food preference indices (P = % ith prey taxon in stomach/% of ith taxon
in wild) are calculated for all skink species living in microhabitats in which
monthly insect abundances are available. These species are Sphenomotphus



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 187

jagori, Lipinia pulchella, Mabuya multifasciata, Mabuya multicarinata, and
Lamprolepis smaragdina. In none of these species do the data suggest that
specific insect taxa are con5istentlv selected in proportions greater than they
occur 'in nature (i.e. index greater than 1.0). However, variations in the
number of high indices, the prey categories represented by them, and the
months during which they occur do suggest several important patterns. M.
mult(fasciam shows the least food preference of any species tested (11 of 72
possible cells in Table 24). In this species, spiders occur in significantly high
proportion more often than any other prey. The same pattern occurs in M.
multicarinata. During December prey preference indices are high in most
food taxa. In Sphenomolphus jagod the preferred prey for over half of the
year are orthopterans (June and August, through December). January shows
high prey preference indices in almost all prey categories analyzed.
Lamprolepis smaragdina has more high preference indices for more months
for more prey categories than most local skink species; Diperta and
Orthoptera are the most consistently taken in high proportion; November has
the highest number of high indices for any month. Only Lipinia pulcheUa has
a greater number of high preference indices (22 of 72 possible cells, see Table
24); ants, spiders, and flies all occur in high proportions during many months
of the year; January is the month with the greatest number of high indices.

To summarize, it appears that high preference indices are (1) more
typical of the period during the end and immediately following Monsoon II,
(2) often found associated with spider and fly prey, and (3) found more often
in arboreal than terrestrial skinks. Some of this can be explained by the
apparent need for skinks to forage for hidden, inactive insects (1) during and
after the heaviest rains of the year, and (2) in arboreal habitats. It is probably
the inactivity of these prey, rather than their low actual abundances which
explains this particular pattern of high prey preference indices. In the case of
spiders and flies, we suspect that the higher proportion of both in the gut
than in nature may actually be due to some selection on the part of the lizard
predators.

When the patterns of seasonal insect utilization are compared to the
seasonal abundance of insects in each of the preferred microhabitats of each
skink species, a significant correspondence can be demonstrated (Table 25),
except for the underrepresentation of both ants and flies in the stomachs
when compared to their numbers in the local environments. This
misrepresentation is probably related to the difficulty with which flies are
captured and the fact that ants are rarely eaten by skinks, except by some of
the arboreal species (see above). When Formicidae and Diptera are excluded
from the analysis, a Spearman Rank Correlation Test suggests that there is a
highly significant correlation between the abundance rankings of stomach and
wild populations of insect prey (RS = 1.00, Z = 1.73). Thus we conclude that
for almost all insect prey they are taken in direct relation to their abundance



188 BULLETIN FLORIDA SrATE MUSEUM VOL. 32(2)

in each of the microhabitats studied. It can be demonstrated that the
occurrence of seasonal prey switching is related to local changes in prey
densities and is probably not due to differential preferences or to interspecific
competition.

The following section describes the seasonal utilization pattern of each
of the Caramoan skinks studied. Details are provided in Tables 26-35.

Bmchymeles boulengeri has a seasonal prey utilization pattern (Table 26),
in spite of the fact that it is fossorial. The only prey taken continually
throughout the entire year are coleopterans. However, the utilization pattern
is erratic, with one month of high utilization followed by another of low
utilization. Almost all the Coleoptera taken are larval morphs, and the
pattern may reflect seasonal pulses of different developing beetle groups. In
January there is major dependence on mollusks, beetles (larvae), and
orthopterans. In February and March the diet changes to spiders and
pillbugs, some beetle larvae, and particularly earwigs. This represents the
highest utilization rate of earwigs for any Caramoan skink species at any time
of the year. The following warm, dry period of April and May witnesses
replacement of all these categories by termites, moth larvae, orthopterans,
and some snakes. With the rain of the first monsoon in June, centipedes,
isopods, and beetles join the categories heavily predated. The next major
change occurs in the August dry period, between monsoon rains, when
snakes, lizards, beetles, and moth larvae, as well as centipedes, continue to be
well represented among the stomach contents. These are particularly
common prey categories during the wet months of November and December.

The seasonal pattern is entirely different in the semiaquatic
Tropidophoms grayi (Table 31). While termites are eaten during almost the
entire year, over 40 percent of the yearly total are consumed during
September. Lower peaks occur in January and June. This pattern occurs in
no other species studied. With the exception of January, the peak termite
feeding periods are probably related to changes in local rainfall. During wet
periods, the low-lying areas in which Tropidophoms grayi live become water-
logged, driving termites into the open. The seasonal pattern of feeding on
lepidopterans also differs from that of most other local skinks. Fishes are
eaten only during the dry seasons--presumably because the small streams
along which this species most often occurs are represented by small scattered
pools, in which fishes are evidentally easily caught. Captives maintained in
Gainesville, Florida, have frequently been noted to chase and capture live fish
in shallow water.

Lamprolepis smaragdina, Lipinia pulchella, and Dasia grisia are all
more or less arboreal, but the seasonal patterns of prey utilization are quite
different in each species (Tables 31, 33, 34). Ants are eaten in rather high
proportions throughout the year by Lpinia pulchella, but over 60% of those
eaten by Dasia gnsia are during July. Lamprolepis smaragdina feeds on them



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 189

extensively during the first half of the year and into the first monsoon. On
the other hand, the seasonal pattern for Lepidoptera (mainly larvae)
predation is essentially the same for all three species. All the mollusks eaten
by Caramoan skinks are land snails. They are rarely eaten by D. gn'sia, but
commonly by the other two species. The high level predation on snails by L.
smaragdina from January to April, when these prey are generally not moving
about but found under surface debris, suggests that this species regularly
descends to the ground and scratches about in leaf litter at this time of year.
This is also suggested by the high use of pill bugs and fruits. Ants are eaten
throughout the dry period and are probably largely foraged on the tree
trunks, for during this time of year huge streams of them are often seen
moving up and down in very exposed places.

The seasonal feeding patterns of the three terrestrial and narrowly
sympatric species M. multicarinam, M. mul«fasciata, and S. jagon' are all
somewhat dissimilar. Though some prey categories, such as orthopterans, are
eaten by all three during more or less the same seasons, the patterns of prey
category consumption for particularly M. multicarinata and M. mumfasciam
are interdigitating, with little overlap in many prey groups. This may be
coincidence, but of the three terrestrial species in forested communities, these
two species show the most prey overlap. With the exception of Coleoptera
and Lepidoptera, S. jagori and M. multicarinata represent quite different
seasonal feeding patterns.

Thus we conclude that the local skinks illustrate significant seasonal
changes in prey utilization. While there is some overall correspondence in
these changes that can be related to the absolute differences in abundance of
certain insect groups at different times of the year, it is also clear that some
changes reflect a need to change foraging tactics due to local shortages or
abundances (e.g. Lamprolepis smaragdina does more foraging on the ground
during certain seasons, and Tropidophoms gmyi forages for fishes
concentrated in drying pools, etc.). The only situation which might suggest
that interspecific interactions are affecting seasonal prey choice would be in
those similar species with similar feeding habits inhabiting overlapping
microhabitats on the forest floor. Of the total Caramoan skink community,
only about one-quarter can be said to fall in this category. Thus three-
quarters of the local skink species seem to be free of competition over
seasonal food resources.



190 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

Abdominal Fat Bodies

Female Abdominal Fat Cycle.-- The annual cycle in fat bodies of the
female Caramoan skinks shows considerable interspecific variability (Table
36). Some of this variation can be explained; some cannot.

Of the 11 species in which abdominal fat bodies were weighed monthly,
approximately one-half (55%) possess no appreciable amount of fat at any
time of the year. These non-fat containing species are Sphenomoiphus jagon
Otosaurus cumingii, Lipinia pulchella, Brachymeles boulengeri, B. samarensis,
and Tropidophoms grayi. The list includes species characteristic of
semiaquatic, terrestrial forest, arboreal, and fossorial microhabitats.
Comparison of these microhabitats with insect seasonal abundances in each
does not necessarily suggest that these habitats are blessed with high food
resources throughout the entire year. In fact, some of these microhabitats
(such as forest trees, or rocky forest substrates) have rather low food
resources compared to other microhabitats in the immediate area in which
other species of skinks live. Additionally, this species list includes skinks that
represent a wide range of annual reproductive patterns (see below), so that
the lack of abdominal fat cannot be related to a specific breeding pattern.

The remaining five skink species produce abdominal fat, and the amount
produced in each varies seasonally. In general, the period of maximum fat
production is during the second monsoon (October through December, see
Table 36). Emoia atrocostata possesses the most fat from August to October
and is thus the only species somewhat out of line with the remaining ones. In
all five species the least fat is found during the period just before and into the
first monsoon period.

When this general pattern is compared with the annual reproductive
patterns of the skink species involved, we find that there is no correlation, for
the five species demonstrate a variety of annual breeding cycles (see below).
The annual cycle of abdominal fat deposition and depletion shows the best
correlation with annual fluctuation in insect abundance (see Fig. 10). Fat
reserves are accumulated during the first monsoon, when insect abundance is
high. Maximum fat loads are accumulated by the beginning of the major
rainfall in the second monsoon (November and December), when insect food
resources are generally rather low. The fat reserves are then steadily depleted
through the spring dry season and reach their lowest levels at the end of that
season and the beginning of the first monsoon. Thus the fat accumulated
during the first monsoon and the period following it (about four months) is
used during the remaining seven to eight months--the utilization rate
undoubtedly dependent on food abundance as well as the energetics of the
skink species involved.



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 191

Male Abdominal Fat Cycle.-- The same species that lacked abdominal
fat in females also lacks it in males. Of those species in which the males do
contain abdominal fat, it is also seasonally variable, as in the females of the
same species (Table 36).

In general, the seasonal pattern is very similar to that of the females, i.e.
the greatest fat accumulation occurs during the second monsoon and the
least during the early part of the first monsoon and the dry period
immediately preceding it. In Lamprolepis smaragdina the period of high fat
reserves is longer than in males (or females) of any other species studied,
beginning in September, with the peak in October. This is also the only local
skink species in which the males contain significantly more abdominal fat
than the females (t = 24.3, df = 20, p < 0.001). In the remaining species,
females have greater amounts of mean monthly fat, but the differences are
not statistically significant in any sex related comparisons.

The variation of the abdominal fat weight in males and females in the
monthly samples of each species shows significant values that can be related
to seasonal food supply. Coefficients of variation (= CV) for mean monthly
abdominal fat weight were calculated for males and females. Such
coefficients negate size differences between the species and allow direct
comparison of the resulting percentage values. There is no significant
difference between the annual mean CV values of the males and females of
Mabuya multican)lara and Emoia atrocosmta, whereas the males of M.
multifasciata and Lamprolepis smamgdina have significantly less variation in
fat weight throughout the year than females of the same species. The reasons
for this are not clear.

The seasonal pattern of the degree of variation in fat weight shows that
the greatest variation in fat weight occurs during the end of the dry season
and the earliest part of the first monsoon. This has been shown above to be
the period when fat reserves are usually the lowest of the entire year in all
species that have fat reserves. The fact that variation is greatest during this
period suggests that some individuals are probably able to continue to find
food during this high stress time, while others are not and are thus more
dependent on their abdominal fat reserves. On the other hand, in all species
studied, the time of year when fat reserves show the least variation in both
males and females of all species studied is during the heavy rains of the
second monsoon and the beginning of the dry season immediately following
them. This is the time when food resources begin to get slim. The fact that
all individuals of both sexes of all species have built up a fat supply in more
equal amounts suggests that the accumulation of fat during the preceding first
monsoon must be a very important strategy for all species. This is particularly
cogent when one realizes that there are a variety of reproductive strategies
operative among these species, and that they cannot be directly related to the



192 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

fat accumulation and utilization patterns in the different species (data
currently being analyzed by W. and T. Auffenberg ).

CONCLUSIONS

The data presented above show that (1) the Caramoan peninsula of
southern Luzon contains a number of habitats and no species of skink
studied ranges through all of them; (2) dense forest types are the richest local
communities in number of species, and evidence suggests that this is due to
their greater structural complexity; (3) the distribution of the terrestrial
species Mabuya multifasciata, M. multicarinata, and Sphenomorphus jagori are
about the same size and replace one another ecologically. A fourth terrestrial
forest species, Otosaurus cumingii, that is syntopic with these is much larger.
The fossorial species pair Bmchymeles boulenged-B. samarensis is significantly
different in size and replace one another ecologically. The arboreal forest
species L*inia pulchella and Dasia glisia are dissimilar in size and replace one
another vertically in the forest vegetational strata; (4) the dense and open
forest skink community seems to comprise two distinct ecological units; and
(5) in general, these conclusions for a Philippine skink community are similar
to those for a complete lizard community of several different families in
Brazilian forests (Rand and Humphrey 1968).

We would now like to return to the questions posed in the introductory
section. Some of these, such as evidence of seasonal prey switching, have
been answered adequately in the body of the text. However, others more
important and wide reaching require additional comment.

Food as a Limiting Resource.-- Information obtained during this study
of the skink community of southern Luzon, Philippines, does not provide
adequate data to prove that food is a limiting resource for the species found
in the local environments. Data needed for such analyses are currently
lacking and include (1) the amount of food skinks need to survive and
reproduce, and (2) the length of time they can go without food (or subsist on
a minimal amount of it) before either survival or reproduction is affected.

However, our data do show that there is, at least within the insect prey
eaten by the species studied, little segregation of prey size by most of these
skinks. Some are limited to only the smaller insects as food, but even the
largest species, which can feed on very large insects and smaller vertebrates,
also con5ume a great number of prey items well within the range of the
smallest local skink species. There is no evidence of prey selection depending
on predator size, nor is there any evidence of prey selection on the basis of
nutritional factors. Almost all the evidence of seasonal prey shifting
documented here can be explained as being due to demonstrated changes in



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 193

prey abundances at different seasons. The only suggestion of shifts in prey
selection caused by possible interspecific interactions is among three
terrestrial species inhabiting secondary and primary forests and the ecotonal
zones between them. These are, additionally, the most narrowly sympatric
skink species among those studied. The remaining species of the local skink
community are apparently not significantly affected by food competition from
other local species.

Availability of Prey.-- Huffaker (1966) has suggested that food could be
in short supply whenever the predator lacks the capacity to locate or utilize it
efficiently. While some references to tropical forest ecosystems suggest that
insect prey are equally abundant throughout the year, our study shows that
this is certainly not the case in southern Luzon. In general, the period of
lowest insect abundance in the study area is from November through April.
However, our data also show that food abundances vary from habitat to
habitat--even within the same geographic area. Some areas suffer less
variation in food abundance through the year than others. There is, for
example, no evidence that Emoia atrocostata, living in a marine littoral
environment, ever suffers food scarcity. Casual observation on the local
beaches suggests that the crustaceans forming the major prey of this skink are
available in more or less equal numbers throughout the year:, .lIn spite of this
stable and relatively abundant food supply, only this species of the 11 found in
the entire area feeds on this consistent and abundant food resource.
However, to search for and excavate the beach crustaceans must subject E.
atrocostata to relatively high predation pressures, since the habitat is devoid
of much cover. Additionally, the habitual feeding on marine forms, as well as
the habitat itself may subject this lizard to salt loads which the other species
may find intolerable.

Within the adjacent forests there are 10 additional skink species. Most
of these are found in somewhat different microhabitats. Thus food shortages,
if they occur at all, probably do not result in food competition between them.
If competition does occur, and if it is important in their survival, it must be
during the months of November through April, when food resources tend to
be at their lowest annual levels.

Food Niche Overlap.-- The most important ecological differences we
have documented for the Caramoan skinks are in habitat utilization. Species
that live in different places are expectedly exposed to different prey types and
seasonal schedules of microclimate and food availability. For the most part,
almost all of the differences in diet between these geographically sympatric
species can be attributed to differences in habitat. At the same time, those
few species that do live in close proximity in nearly the same microhabitat
show the greatest evidence for low food niche overlap values and differences
in foraging periodicity and thus represent the only evidence for possible
competition among any of the local species.



194 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

Food niche overlap values are not, of course, proportional to intensity of
competition; nor does high food niche overlap necessarily imply strong
competition. However, given the relative magnitudes of food niche overlap in
particularly the terrestrial forest skink community, the chances of competition
are greater here than in any other habitat in the entire area. As in the two
broadly sympatric Mabuya species of southern Africa studied by Huey and
Pianka (1977), niche overlapvalues must be concluded to be simply consistent
with a hypothesis that relatively strong interspecific competition between the
terrestrial forest species of southern Luzon may help restrict the zone of
coexistence. It is Dossiblv for these reasons that Mabuya mulnfasciata,
Mabuya multicannata, and Sphenomoghus jagod inhabit slightly different
microhabitats in the same general area, eat slightly different foods and forage
at different times of the day.

Several authors have suggested that narrowly sympatric species are often
interspecifically territorial or aggressive (Brown 1971, Cody 1974, Nevo et al.
1975). Though no evidence of aggression was noted between M. multican)tam
and S. jagod, M. mul*sciata was regularly seen chasing individuals of M
multican'nam. This is consistent with the fact that the stomachs of M
multifasciata often contain entire lizards or their tails (see Tables 26-35).

To summarize, our evidence supports two explanations for local
distributional patterns of scincids in southern Luzon. First, the separation of
the distributions in a number of local microhabitats probably reflects
morphological, physiological, and behavioral adaptations of seven of the local
species to specific microecological discontinuities of the local forest
ecosystems. Given the variety of microhabitats in a tropical moist forest, such
as that at Caramoan, and the number of niches represented in each of the
microhabitats, we conclude that there are probably many more niches
available for skinks than species able to fill them. Of course, many such
niches are probably filled with non-skink predators in the local forests.
Secondly, within the terrestrial forest floor niche, at least some competition
between three local species falling into this category may restrict their zones
of sympatry. The most aggressive and Largest species (Mabuya mulnfasciata)
lives in that part of the local habitat that contains the greatest food
abundance.

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198 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

Table l. Summary of meristic data relating to the scincid species studied at Caramoan, Luzon.

SVL (mm) X Female X Male Total
Species at Maturity SVL Wt SVL Wt Examined

L.pulchetta 35 39 0.6 38 0.5 355
M. multgasciata 72 90 22.6 91 23.1 378
M. multicarinam 60 71 11.5 71 11.3 353
T. grayi 79 94 18.9 94 19.1 368
S.jagori 61 75 13.9 81 17.8 363
L. smamgdina 70 92 18.6 90 15.8 358
B. boulengen 71 86 14.5 77 11.9 350
B. samarensis 55 59 1.9 61 2.0 43
0. cumingii 110 121 43.5 113 38.8 305
D. gnsm 65 107 27.3 104 26.8 61
E. atrocostata 71 84 12.6 89 14.8 318

Table 2. Body size gradation ratios in Caramoan skinks and general habitat.

Species SVL (mm) Ratios General Habitat

S. steerei 27.0 ---- Terrestrial , forest
L. pulchella 38. 1 1.41 Arboreal. forest
B. samarensis 60.0 2.22 Fossorial , forest
M. multicarinata 71.0 2.63 Terrestrial, forest
S. jagori 78.1 2.89 Terrestrial , forest
B. boutengeri 81.5 3.02 Fossorial , open
E. atrocostata 86.2 3. 19 Marine littoral
M. multifasciata 903 3.35 Terrestrial , open
L. smaragdina 92.0 3.41 Arboreal, open
T. grayi 94. 1 3.49 Semiaquatic
D. grisia 105.0 3.89 Arboreal, forest
0. cumingii 117.0 4.33 Terrestrial , open



Table 3. Habitat use by three sympatric Caramoan scincids.

Habitats

Fields Ecotonal Forest

River Forest Dense Rocky
Species Bed Edge Shrub Floor

M. multifasciam 16 56 33 5 1
M, multicannata 0 0 10 44 7
Slagon 0 0 2 15 34

Totals 16 56 45 64 25

Table 4. Mean body lengths (SVL, in mm) for skinks living in different habitats.
Number of skink specieskategory in parentheses.

Terrestrial Fossorial Arboreal Total Sp.

Dense Situations 58.7 (3) 60.0 (1) 71.5 (2) 6
Open Situations 97.8 (3) 81.5 (1) 92.0 (1) 5

Total Species 6 2 3 3

Table 5. Basis of food analyses for species examined.

Total with Food Percent with Food
Species in Stomach of Total Examined

D. grisia 46 75
L. smaragdina 251 70
L. pulchella 206 58
M. multifasciata 235 85
M. multicarinata 230 65
B. boulengeri 280 80
B. samarensis 35 81
S. jagori 182 69
T. grayi 221 60
0. cumingii 163 59
E. atrocostata 244 77

Total 2093 779



200 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

Table 6. Prey utilization of scincids in the Caramoan area

Total Items Percent
Prey Taxa Taken of Total Remarks

Mollusca 79 0.74
Arthropoda

Crustacea
Isopoda 409 3.81 Including littorals
Decapoda 152 1.42 Littorals only
Chilopoda 34 0.36

Arachnida
Chelonethida 1 0.01
Phalangida 2 0.02
Scorpionida 12 0.11
Araneida 299 2.73

Insecta (eggs only) 61 0.57
Collembola 14 0.13
Odonata 7 0.08
Isoptera 6735 62.65
Dermaptera 16 0.15
Hemiptera 30 0.28
Homoptera 9 0.08
Formicidae 348 3.24 Including 6 eggs
Coleoptera 1142 10.63 Adults and larvae
Lepidoptera 465 4.33 Adults and larvae
Diptera 201 1.87 Including 6 larvae
Orthoptera 615 5.73

Annelida
Oligochaeta 11 0.10
Polychaeta 1 0.01

Chordata
Pisces 12 0.13
Amphibia 1 0.01 Adult
Reptilia
Sauria 32 0.30 Including l egg
Serpentes 15 0.14 Including 1 egg

Aves 2 0.02 Including 1 egg
Plants 46 0.43 Angiosperm fruits

Total 10,739



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 201

Table 7. Comparative major dietary items in Caramoan skinks. For SVL size ratios, Lipinia
pulchella is used as the base.

Major Food Categories (%)
Size

Species Ratio First Second Third

L. pulchelia - Isoptera(33) Coleoptera(26) Formicidae(26)
B. samarensis 1 .57 Isoptera(78) Formicidae(12) Oligochaeta(05)
S. jagori 1 .74 Isoptera(81) Coleoptera(04) Isopoda(03)
D. grisia 1 .86 Coleoptera(49) Isoptera( 16) Formicidae(08)
L. smaraagdina 2.00 Coleoptera(42) Lepidotera(23) Fruits( 11)
E. atrocostata 2.02 Decapoda(68) Isoptera(12) Isopoda(09)
B. boulengeri 2.03 Isoptera(70) Coleoptera(23) Araneida(02)
M. multifasciata 2.14 Isoptera(43) Orthoptera(19) Coleoptera( 14)
T. grayi 2.17 Isopoda(62) Coleoptera(14) Isoptera(08)
0. cumingii 3. 14 Oligochaeta(24) Orthoptera(24) Coleoptera(20)



Table 8. Seasonal Shannon-Wiener Diversity Indices (D), equitability (E), and number food categories (PC)'for those Caramoan
202 

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skinks with sufficient data for analysis.

Months

Species Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec.

B boulengeri D 1 .64 1 .56 1 .06 0.54 0.31 0.64 0.44 0. 73 2.36 0. 85 1 .00 0. 17
E 0.55 0.55 0.35 0.18 0.12 0.21 0.15 0.20 0.91 0.26 1.00 0.07
PC 8 7886681261025

E. atrocostata D 1 . 73 0.61 0.43 0. 70 0.86 0 1 . 15 1 .32 1 . 00 1 .67 1 . 00 1 .30
E 0.62 0.39 0.27 0.44 0.86 0 0.72 0.83 1.00 0.72 1.00 0.82
PC 7 3 3 3 2 1 3 3 2 5 2 3

S. jagori D 1.69 1 .79 1 .99 0.75 0.76 0.54 0.67 1 .83 1 . 74 1 .35 1 . 39 1 .30
E 0.53 0.57 0.63 0.25 0.25 0.19 0.29 0.65 0.58 0.45 0.40 0.41
PC 9 5 9 8 8 7 5 7 8 8 11 9

T. grayi D 1 .41 2.88 1 .75 2.28 2.23 1 . 14 1 .58 1 .0 0. 16 1 .71 2.35 2.28
E 0.54 0.87 0.88 0 0.89 0.49 1.00 1.00 0.08 0.66 0.91 0.76
PC 6 10 4 6 6 5 3 2 4 6 6 8

L. pulchella D 1.82 1.72 0.95 1 .61 2.05 1 .76 2. 35 0.99 1 .72 1 . 87 2.07 2.27
E 0.78 0.74 0.47 0.62 0.65 0.58 0.74 0.62 0.67 0.72 0.69 0.72
PC 5 5 4 6 9 8 9 3 6 6 8 9

M. multifasciata D 1.55 2. 15 1 .67 1 .36 1 .48 2.03 2.01 2.52 2.80 2. 60 1 . 99 3. 00
E 0.49 0.65 0.50 0.48 0.49 0.61 0.78 0.76 0.81 0.75 0.71 0.87
PC 9 10 10 7 8106101111711

M. multicarinata D 2. 53 1.00 2.28 2.09 1 . 09 0.79 2.63 2. 79 2.49 1 . 85 1 . 52 2.54
E 0.84 0.32 0.76 0.66 0.36 0.26 0.71 0.78 0.69 0.58 0.45 0.85
PC 8 9 8 9 8 8 13 12 12 9 10 8

L. smaragdina D 1 . 16 2.21 2.34 2.92 2.25 2.05 1 . 14 0.81 1 .58 2.33 2. 63 1 .30
E 0.39 0.74 0.78 0.88 0.87 0.79 0.57 0.81 1.00 0.90 0.79 0.46
PC8881066423 6 10 7



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 203

Table 9. Standardized food (category) niche breadth (B~t) in Caramoan
skinks.

N Food Standard N Prey
Species Items Food Niche States

D. grisia 146 0.219 10
T. grayi 148 0.009 13
E. atrocostata 178 11 . BO 11
B. samarensis 46 3.331 5
B. boulengeri 195 0.013 13
L. smaragdina 280 0.003 16
S. jagori 240 0.006 15
M. muitifasciata 390 0.012 15
M. multicarinata 383 0.007 15
L. pulchella 288 0.042 11



204 BULLETIN FLORIDA SrATE MUSEUM VOL. 32(2)

Table 10. Niche overlap (C~h· X 100) among Caramoan skinks for Isoptera prey.

L. p. M, f, M. c. L. s. S. j. D. g. T g E. a. B. b.

L. pulchena
M. multifasciata 0. 12
M. multicarinata 0. 10 0. 10
L. smaragdina 0. 13 0.45 0.25
S. jagori 0.03 0.09 0.02 0.01
D. grisia 0. 10 0.09 0. 11 0.03 0.06
T. grayi 0. 10 0. 10 0. 12 0.03 0.06 0. 12
E. arrocostata 0. 13 0.33 0.23 0.24 0.07 0.21 0.22
B. boulengen 0.04 0.01 0.02 0.01 0.04 0.02 0.02 0. 01
0. cumingii 0.12 0.27 0.21 0. 15 0.06 0.19 0.20 0.27 0.08

Table 11. Niche overlap (Cih· X 100) among Caramoan skinks for Crustacea prey.

L. P M, f. M. c. L. s. S. j. D. g. T. g. E. a. B. b.

L. putcheita
M. multgasciata 0.07
M multicarinata 0.01 0.07
L. smaragdina 0.26 0.28 0. 16
S. jagon 0.01 0.03 0.04 0. 01
D. grisia 0.38 0.30 0.16 0.44 0. 10
T. grayi 0.01 0.05 0.07 0.03 0.07 0.02
E. atrocostata 0.00 0.00 0.00 0.00 0.01 0.00 0.00
B. boulengeri 0.02 0.08 0. 10 0.05 0.08 0.04 0.09 0.02
0. cumingii 0.24 0.27 0. 16 0.34 0. 10 0.33 0. 13 0.02 0. 18

Table 12. Niche overlap (Cjh· X 100) among Caramoan skinks for Coleoptera prey.

L. P. M. f. M. c. L. s. S. j. D. g. T. g. E. a. B. b.

L. pulchella
M. multifasciata 0.06
M. multicarinata 0.07 0.0'7
L. smaragdina 0.05 0.02 0.01
S. jagori 0.05 0.03 0.02 0.03
D. grisia 0.04 0.02 0.01 0.02 0.02
T. grayi 0.06 0.04 0.02 0.04 0.04 0.03
E. atrocostata 0.07 0.09 0.05 0.06 0.06 0.04 0.07
B. boutengen 0. 10 0.05 0.03 0.04 0. 17 0.08 0.04 0. 13
0. cumingii 0.10 0.05 036 0. 12 0. 17 0.08 0.37 0. 13 1 . 05



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 205

Table 13. Niche overlap (Cih' X 100) among Caramoan skinks for Lepidoptera prey.

L. P. M. f M. c. L. s S. j. D. g. T. g. E. a. B. b.

L. pulchelia
M. muttifasciata 0.01
M. multicarinata 0.16 0.09
L. smaragdina 0.00 0.02 0.01
S. jagori 0.04 0.07 0.06 0.04
D. grisia 0.05 0.07 0.07 0.04 0.09
T grayi 0.06 0.08 0.08 0.04 0.10 0.10
E. atrocostata 0.06 0.09 0.36 0.05 0. 16 0.18 0.20
B. boukngen 0. 12 0.08 0.00 0.05 0. 12 0. 13 0. 14 0.02
0. cumingii 0.04 0.07 0.05 0.04 0.07 0.07 0.07 0.01 0.06

Table 14. Niche overlap (Cih, X 100) among Caramoan Skinks for Orthoptera prey.

L. P. Mf M. c. L. s. S. j. D. g. T. g. E. a. B. b.

L. pulchelia
M. muttifasciata 1 .00
M. multicarinata 0.90 0.91
L. smaragdina 0.98 0.99 0. 14
S. jagori 0.92 0. 18 0.27 0.20
D. grisia 0.99 1.65 0. 12 4. 17 0. 16
T. grayi 0.93 0.20 0.53 0.25 2.86 0. 18
E. atrocostata 0.97 0.70 0. 10 0.44 0. 10 0.18 0.08 0. 10
0. cumingii 0.99 1 . 03 0. 12 8.00 0. 17 0. 10 0.08 0.02 0. 08

Table 15. Overall niche overlap Call major prey taxa added together, X 100)

L. P. M. f, M. c. Ls S. j. D. g. T. g. E. a. B. b.

L. pulchella
M. multifasciata 35.15
M. multicarinc:fa 35.87 35.20
L. smaragdina 52. 12 88.63 49.10
S. jagori 14. 12 24.37 18.48 12.42
D. grisia . 68.42 59.23 43.15 64.67 34.70
T. grayi 25.91 29.60 34. 10 17.31 30.73 30.56
E. atrocostata 103.68 72.78 78. 16 52.21 37.41 65.88 54.53
B. boulengen 44.49 40.41 22.14 29.56 32.73 31. 18 39. 16 16.26
0. cumingii 56.99 77. 13 51.40 68.89 23.99 74.20 53.92 32.98 45 .37



206 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

Table 16. The nutritional quality of terrestrial invertebrates, shown as percent of dry weight, means
in parentheses.

Taxa Water Ash Nitrogen Fat Source

Annelida
Oligochaeta 82-85(83) 9-23(16) 9-11(10) 4-8 (6) 1,7,8

Arthropoda
Orthoptera 57-76(69) 4-9 (7) 7-12(10) 4-50(17) 1,2,4,5
Coleoptera 52-80(66) 5-10(7) 9-19(11) 5-33(16) 1, 6
Lepidoptera 56-82(73) 5-10(7) 5-9 (8) 4-61(29) 1,3,4,6
Diptera -------- 5-12(9) 10 (10) 9-15(12) 5
Hymen6ptera 44-70(59) ------- 1-10(5) 3-51(25) 2,3,6,9
Isoptera 34-81(66) 2-71(17) 6-11(8) 8-53(30) 2,9,10,

11, 12, 13

Sources: 1, Oftsal unpubl. in 9; 2; Leung 1968; 3, Leung 1972; 4, Goh] 1975; 5, DeFolliart 1975; 6,
Taylor 1975; 7, Lawrence and Miller 1945; 8, French et al. 1957; 9, Redford and Dorea 1984; 10,
Ketelhodt 1966; 11, Matsumoto 1976; 12, Phelps et al. 1975; 13, Hladik 1977.

Table 17. Frequency of food size classes (total measured food items 2585).

Frequency Food Size Classes (mm)

Species 1-5 6-10 11-15 16-20 21-25 26-30 31-40 41-50 51-80 Other

M. mulnfasci'ata 60 238 63 19 1 1
M. mumcarinata 29 189 111 25 12 11 7 5
L. pulchella 249 45 1
L.smaragdina 34 118 60 29 16 7 6 2 2
S. jagon 102 216 57 17 2 4 3
D. grisia 6 48 29 9 3 1
Tgrayi 13 65 43 9 10 2 2
E. atrocostata 2 81 61 3 3 3 1 1
B. brachymeles 20 91 24 16 3 2 16 5 1 73 2
B. samarensis 43 38 83 2

91 1
111 1

0. cumingit 12 115 46 23 11 8 23 16 5 62 3
200 1
151 1

Totals 570 1244 495 150 61 39 58 29 9 17



AUFFENBERG AND AUF*ENBERG: PHILIPPINE SKINKS 207

Table 18. Mean particle size and SVL (mm) of Caramoan skinks. -

Prey Skinks

Species Mean SD N Items SVL SD N

M. multifasciata 9.64 534 388 90.5 2.0 135
M. multicannata 11.83 7.06 387 71.0 2.5 160
L. pulchella 3.79 1.25 295 38. 1 0.8 106
L. smaragdina 11.33 6.89 274 92.0 1.8 151
S. jagori 8.26 4.82 401 78.0 6. 1 162
D. grisia 10.66 4.40 96 105.0 1 .5 23
T. grayi 11.29 5.96 144 94. 1 8. 1 121
E. atrocostata 10.63 3.69 155 86.7 3.4 139
B. boulengeri 15.20 15.99 186 813 4.8 87
B. samarensis 5.62 2.01 81 50.7 2.3 43
0. cumingii 16.18 12.60 265 118.9 12.0 63



208 
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Table 19. Differences in insect mean food particle size between skink species pairs by analysis of variance a (F values).

M. m M. c L. P. S. S. S.j. D. g. E. a. B. b.

M. multifasciata 0. 16 12.07 3. 18 0.41 0.60 2. 12 5.31 0.01
M. multicarinata 36.46 0.52 3.38 4033 2.86 3.22 1.86
L. pulchella 23.68 9.23 0.02 18.53 10.81 18.55
S. smaragdina 3.53 3.89 2.24 1 .48 0.78
S. jagori 0.68 0.05 0.05 1 .80
D. grisia 0.34 0.51 1 .57
T. grayi 0.25 1 .86
E. atrocostata 6.38
B. boulengeri
B. samarensis

a Sums of squares, simultaneous test procedure. Bold F values significantly different at a level less than .001.



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 209

Table 20. Mean volume of ingested food items by prey categories and percent
of total volume of all foods eaten.

Meaq Prey Vol. Total Food Percent of
Prey Category (mm- per item) Recorded (mm3) Total Food

Mollusca 41.3 326.3 2.8
Isopoda 6.8 27.81 2.4
Chilopoda 18.8 6.39 0.6
Araneida 3.5 10.46 0.9
Insect Eggs 0.4 0.24 trace
Isoptera 7.2 484.92 42.1
Formicidae 3.2 11.14 1.0
Coleoptera 9.6 22.84 2.0
Lepidoptera

larvae 23.2 86.54 7.5
adults 20.1 18.49 1.6

Diptera 2.0 4.02 0.3
Orthoptera 51.8 318.57 27.7
Sauria 198.0 63.36 5.5
Serpentes 140.0 21.03 1.8
Fruits 55.9 42.48 3.7



210 
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Table 21. Seasonal insect abundance in local skink microhabitats.

Microhabitats

Field Forest

Months Open Edge Rocks Trees Crevices Rocks Litter Trees

Jan. 12.3 20.9 25.6 4.8 10.2 7.3 13.1 7.3
Feb. 8.9 22.1 8.9 5.3 9.6 8.2 25.1 8.2
Mar. 8.3 12.4 31.4 7.4 5.0 4.1 24.0 4.1
Apr. 13.6 54.0 4.0 1.7 5.1 9.1 9.1 9.1
May 31.6 27.9 5.8 2.7 2.3 5.1 15.3 5.1
Jun. 16.6 40.2 12.6 3.4 11.0 25.1 11.7 25.1
Jul. 14.0 14.2 19.7 6.2 3.0 13.8 19.7 13.8
Aug. 16.1 23.4 15.8 6.0 4.2 10.1 18.1 10.1
Sep. 26.8 21.3 12.4 6.5 4.5 6.3 18.5 6.3
Oct. 18.3 21.8 13.4 9.5 5.6 5.6 20.4 5.6
Nov. 17.2 20.1 20.0 7.8 6.0 6.2 17.5 6.2
Dec. 29.0 18.0 34.5 3.7 6.0 6.1 10.3 6.1

Means 17.7 24.7 15.3 5.4 6.0 8.9 16.9 8.9
SD 7.6 7.3 9.7 3.3 2.8 2.7 5.1 4.9 1



Table 22. Seasonal use of major food categories (all skink species combined)

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct Nov. Dec.

Mollusca 5455 1 1 3 3 13 1 8
Araneida 26 27 33 27 10 12 19 37 18 19 66 49
Isoptera 281 406 487 527 818 1059 525 384 130 365 671 470
Coleoptera 174 90 81 51 86 124 82 69 79 104 101 81
Lepidoptera 20 114 65 68 18 23 59 20 11 11 40 33
Orthoptera 33 62 51 185 37 64 23 46 36 44 75 61

A
U

FFE
N

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G

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N

D
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FFE

N
B

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R

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: 

P
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P

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E

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KS  

211

Oligochaeta 23 11 111
Fruits 7 7 13 3 9 1 10 6 13 37 2

Table 23. Seasonal use of major food resources (by whole percent of category total).

Dry Cool Dry Warm Wet Warm Dry Wet Warm Wet Cool

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Mollusca 13 11 13 13 3 3 8 8 34 3 21
Araneida 9 9 11 9 3 4 6 13 6 6 22 17
Isoptera 4 6 8 8 13 16 8 6 2 6 10 7
Coleoptera 15 8 7 4 7 11 7 6 7 9 9 7
Lepidoptera 4 24 14 14 4 5 13 4 2 2 8 7
Orthoptera 5 9 7 26 5 9 3 6 5 6 10 8
Oligochaeta 20 30 10 10 10 10
Fruits 8 8 15 3 10 1 12 7 15 43 2



212 BULLETIN FLORIDA SI'ATE MUSEUM VOL. 32(2)

Table 24. Preference indices per month for selected prey categories of skinks living in secondary and primary Caramoan
forests. Boldface values suggest prey selection; empy cells = 0.0.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

S. jagon
Araneida 1.0 0.15 0.13 1.0 0.35 0.50 1.5
Formicidae 1.0 1.4 0.1 1.4 0.5 0.5 0.6 1.9
Coleoptera 1.5 0.4 1.2 0.8 0.9 0.3 0.4 0.7
Lepidoptera 1.8 0.8 0.2 0.5
Diptera 1.6 19.5 1.7 3.9
Orthoptera 8.1 0.9 1.1 0.6 1.3 1,5 1.5 1.0 8.2 12.0

L. pulchella
Araneida 1.8 0.8 1.6 1.8 1.6 1.8 1.6
Formicidae 1.1 1.3 2.3 2.9 13 2.7 2.2 0.3 1.1
Coleoptera 1.8 0.3 0.1 2.2 1.7 0.8 0.4 0.1 0 7 0.1 0.1 0.7
Lepidoptera 1.0 0.3 1.3 23 1.0
Diptera 2.2 2.7 1.6 33 3.5 1.1
Orthoptera 1.2 0.6 0.4 0.4 1.1 0.2 0.6 0.8 1.2

M. multijasciata
Araneida 1.5 2.5 2.2 0.1 1.0 1.9 0.4 1.4 1.4
Formicidae 4.0 23 1.0
Coleoptera 0.6 0.4 0.4 0.1 0.5 1.4 0.9 0.3 0.2 0.4 0.3 0.1
Lepidoptera 1.7 3.9 1.0 0.7 0.4 1.7 0.8 0.1 0.1 0.1 0.5
Diptera 0.1 0.8 0.2 0.4 0.3 0.7 0.8 0.2 0.2 0.3
Orthoptera 0.1 1.6 0.1 0.1 0.2 0.3 0.2 0.2

M. multicarinata
Araneida 1.0 0.2 0.4 0.5 1.4 1.0 1.5 1.7 0.3 1.7 0.9
Formicidae 2.3 1.3 1.5
Coleoptera 0.6 0.3 0.3 0.4 0.2 0.5 1.0 1.0 0.4 0.5 0.2
Lepidoptera 0.4 0.5 0.1 0.1 0.2 0.3 1.5 0.6 0.7 1.8
Diptera 1.1 0.4 1.1 0.3 0.4 0.2 0.1 0.1 0.5 1.0 1.7
Orthoptera 0.3 0.2 1.0 0.1 0.3 0.2 0.8 0.4 0.3 0.1 1.2

L smaragdina
Arantida 1.3 1.7 1.3
Formicidae 0.7 0.6 0.4 0.4 3.0 0.4 2.9
Coleoptera 1.5 1.0 1.4 0.2 0.2 0.3 0.3 1.0 0.6
Lepidoptera 2.5 0.1 0.3 3.0 0.3
Diptera 1.0 0.6 0.4 1.0 0.6 0.2 1.7 13 1.2
Orthoptera 3.7 1.5 0.2 0.2 1.0 1.0 1.2 0.4



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 213

Table 25. Percent of total major food categories found in all scincids examined*,
compared with relative abundance (in %) if insects in the Caramoan area.

Percent of Total Percent of Total
Prey Taxa in Stomachs in Nature

Coleoptera 10.7 12.3
Orthoptera 5.8 4.4
Lepidoptera 4.3 3.1
Formicidae 3.2 33.7
Araneida 2.8 2.7
Diptera 1.9 41.7

* Isoptera excluded because trapping technique seriously underestimates these
organisms locally.



214 BULLETIN FLORIDA SrATE MUSEUM VOL. 32(2)

Table 26. Seasonal prey of Brachymeles boulengen (total items/month).

Prey Jan. Feb . Mar. Apr. May Jun. Jul . Aug. Sep. Oct. Nov. Dec. Total

Mollusca 2 1 1 1 2 7
Chilopoda 1347331123
Araneida 22111119
Isopoda 7 11 21 2 7731 3 62
Isoptera 49 40 158 192 203 301 359 241 144 10 261 1958
Dermaptera 4 21 7
Formicidae 12 3
Coleoptera 647248598255
Lepidoptera 131 1 2 5 13
Diptera 11 1 3
Orthoptera 4141811 20
Oligochaeta 11 11 4
Sauria 1 1 111 5 1 4 15
Serpentes 28 12334 15

Totals 71 61 196 206 211 330 380 276 15 169 11 268 2194

a Including an egg.

Table 27. Seasonal prey of Brachymeles samarensis (total items/month)

Prey Jan . Feb. Mar. Apr. May Jun . Jul . Aug. Sep . Oct. Nov.' Dec. Total

Mollusca 2 2
Isoptera 225 3 4 7 5 10 5 3 46
Formicidae 1311 1 7
Coleoptera a 

1 
1

Oligochaeta 11 13

Total 3 3 6 3 2 4 4 8 5 12 6 3 59

a larva·



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 215

Table 28. Seasonal prey of Emoia atrocostata (total items/month).

Prey Jan. Feb. Mar. Apr. May Jun . Jul . Aug. Sep. Oct. Nov. Dec. Total

Isopoda 4 1 6 1.3.3 220
Decapoda 19 18 27 13 15 20 11 7 17 4 1 152
Isoptera 1 5 18 4 28
Forrnicidae 5 5
Coleoptera 2 1 1 4
Lepidoptera 1 1
Diptera 1 1 1 2 5 10
Orthoptera 1 1 2
Polychaeta 1 1
Pisces 1 1

Sauria 1 1

Totals 29 20 29 15 21 20 7 32 8 28 8 8 225

Table 29. Seasonal prey of Sphenomorphus jagori (total items/month).

Prey Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep Oct. Nov. Dec. Total

Mollusca 278 5 32
Isopoda 12 423741010 5 17 4 78
Chilopoda 1 1
Scorpionidae 1 1 1 3
Araneida 713112 94120 3 61
Isoptera 89 27 98 372 196 516 58 43 59 112 435 142 2147
Hemiptera 1 2 3
Homoptera 1 1
Formicidae 4 4 1 4 2 2 9 20 9 55
Coleoptera 6 6 12 12 8 13 1 3 8 10 31 7 117
Lepidoptera 3 5 11 6 1 4 1 1 6 38
Diptera 1 7 3 ' 7 18
Orthoptera 6 4 7 1 4 10 1 3 3 6 7 7 59
Salientia 1 1
Fruits 3 6 512 1 27

Totals 128 46 157 246 396 556 65 71 89 151 557 179 2641

a including eggs.



216 BULLETIN FLORIDA SrATE MUSEUM VOL. 32(2)

Table 30. Seasonal Prey of Tropidophorus grayi ( total items/month)

Prey Jan . Feb . Mar. Apr. May Jun . Jul . Aug. Sep. Oct. Nov. Dec. Total

Mollusca 2 7110
Isopoda 353162 4 14 38
Chilopoda 1 111116
Scorpionidae 5 5
Araneida 1 1
Isoptera 38 4 72 160 3 3 280
Formicidae 12 126
Coleoptera 9 9 1 17 1 1 17 1 3 59
Lepidoptera 4351 1 14
Diptera 1 1 1 3
Orthoptera 15443211121429
Oligochaeta 1 1
Sauria 1 1
Pisces 11243 11
Fruits 1 1

Total 54 36 11 15 16 96 3 2 163 29 12 28 465

Table 31. Seasonal prey of Lipinia pulchel/a (total items/month).

Prey Jan. Feb. Mar. Apr. May Jun . Jul . Aug. Sep. Oct. Nov. Dec. Total

Mollusca 3 1 4
Scorpionida 1 1 2
Araneida 1 1 2 1 1 2 1 2 2 13
Isopoda 4 1 1 6
Insect eggs (sp?) 61 61
Isoptera 28 13 34 42 9 17 16 6 10 11 31 217
Dermaptera 1 1
Hemiptera 132 1 7
Formicidae 23 1 7 14 73 21 1 23 28 2 18 211
Coleoptera 16 11 7 24 15 15 10 7 31 30 32 15 213
Lepidoptera 1 1 13114
Diptera 153 233421
Orthoptera 3 3 221 3 5 4 3 26
Fruit 2 2

Total 72 29 43 77 109 116 58 41 68 77 58 76 824



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 217

Table 32. Seasonal prey of Mabuya multifasciata (total items/month).

Prey Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Total

Mollusca 2 1 1 1 2 1 1 2 11
Isopoda 5 3 7 1 5 5 8 25 36 95
Chilopoda 2 1 .1 4
Araneida 2 11 141 2296644

1 1Insect eggs
Odonota 1 1

Isoptera 100 2 126 41 166 81 38 31 7 3 899
Dermaptera 1 1

Hemiptera 1 1 111218
Formicidae f 4 5 3 17
Coleoptera 27 24 34 14 47 49 52 26 10 16 21 3 323
Lepidoptera 16 85 21 4 6 27 16 4 4 21 4 10 218
Diptera 1 15 2 1 5 3 3 2 1 3 10 46
Orthoptera 4 14 1 164 14 6 8 13 12 10 34 11 291
Oligochaeta 1 12
Sauria 1 1 Za 1 5

Fruits 3 1 5 9

Total 157 158 285 232 244 297 215 92 71 102 71 51 1975

a eggs

Table 33 . Seasonal prey of Mabuya multicarinata ( total items/month).

Prey Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec Total

Mollusca 1 111 4

Isopoda 16 8 9 4 26351810516 129
Phalangida 2 2

Chelonethida 1 1 2
Scorpionida 1 1

Araneida 16 11 15 23 1 6 17 24 12 5 28 15 163

1 1Insect egg
Collembola 1 12 2 14
Odonata 1 1 13

Isoptera 10 316 63 50 58 133 44 45 51 89 199
 36 1094

Dermaptera 1 23118
Hemiptera 2111 112 9
Homoptera 3 1 12 7
Formicidae 1247
Coleoptera 2 6 11 6 1 4 7 18 12 12 5 3 87
Lepidoptera 6 11 1 1 1 7 2 1 1 7 38
Diptera 546 4221248846
Orthoptera 2 20 6 17 3 11 10 28 17 15 22 16 167

Total 56 496 123 104 70 160 100 171 119 139 275 82 1782



218 BULLETIN FLORIDA STATE MUSEUM VOL. 32(2)

Table 34. Seasonal prey of Lamprolepis smaragdina (total items/month).

Prey Jan . Feb. Mar. Apr. May Jun. Jul . Aug. Sep. Oct. Nov. Dec. Total

Mollusca 1131 1 18
Isopoda 1 5118
Chelonethida 1 1
Scorpionida 1 1
Araneida 1 618
Odonata 11 13
Isoptera 1 2 3
Hemiptera 1 1
Homoptera 1 1
Formicidae 43252 1621
Coleoptera 106 30 9 7 5 6 1 3 7 9 47 230
apidoptera 13 16 32 5 10 23 5 6 19 129
Diptera 5446 316 9 12 50
()rthoptera 33212 24320
Sauria 31 1117
Fruits 5 6 8 2 3 10 1 7 23 65

Total 132 65 65 28 25 37 13 9 3 37 71 72 558

Table 35. Seasonal prey of Dasia gn'sia (total items/month).

Prey Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Total

Isopoda .1 1
Araneida 22 4
Isoptera 9 6 2 17
Hemiptera 2 2
Formicidae .9 9
Coleoptera 4 6 12 4 2 18 4 1 1 52
Lepidoptera 2 2 11 2 4
Orthoptera 1 1
Sauria 1 1 1 3
Fruits 21 1 21 7

Total 212'14 9 19 14 2 22 10 7 5 107



AUFFENBERG AND AUFFENBERG: PHILIPPINE SKINKS 219

Table 36. Seasonal variatian in abdominal fat (in g)of Caramoan skink species, by sex. Those species missing
produce no abdominal fat accumulations. t = trace only.

Species Sex Jan. Feb. Mar. Apr. May Jun. Jul. Aug: Sep. Oct. .Nov. Dec.

E. atrocostata F 0.2 0. 1 0.2 ttt 0 0.4 0.2 0.5 0.3 0.3
M 0.4 t 0.1 0 t t 0 0.4 t 0.5 0.3 0.6

M. multicarinata F 0.5 0.5 0.4 0. 1 t t .3 t 0.5 0.2 1 .2 0.7
M 0.2 0.3 0.1 0.1 t 0 0 0.2 0.6 0.3 0.9 0.4

M. muttifasciata F 0.7 0.5 0.8 0.3 0.2 t t 0.8 0 1.0 0.9 0.7
M 0.1 0.3 0.3 0. t 0 .2 0.6 0.6 0.5 0.6 0.5

L.,smaragdina F 0.2 0.3 0.2 t 0. 1 t 0 0.2 0. 1 0.3 0.3 0.3
M 0.4 0.2 0.1 0.1 0.5 0.2 0.3 0.2 0.4 1.0 0.4 0.8

D. grisia F 1 .5 0.5 t 0.2 0.4 0.9 2.5 1 .0 0.3 0.9 2.5 1 .6
M 0.9 0.1 t 0.2 0.3 0.1 t 0.9 t 0.5 1.6 1.6



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