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192 IGUANA  •  VOLUME 13, NUMBER 3  •  SEPTEMBER 2006 HARLOW AND MORRISON

Adult Fijian Crested Iguana (Brachylophus vitiensis).

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Just 30 minutes earlier, we had left the Fijian village of
Denimanu on Yadua Island in totally calm weather, but with

heavily overcast skies, and were now skimming over gray waters.
First stop on the 8-km boat trip to Yadua Taba Island is always
to get fresh water from the only permanent stream on Yadua, in
the small bay of Waisevu (Fijian for “welcoming water”).
Because the creek near the village only flows during the wet sea-
son, the 120 inhabitants have to rely on tank or well water for
most of the year and rarely have enough to spare. On the smaller
island of Yadua Taba, no permanent fresh water exists, probably
the main reason it has remained uninhabited.

As we left Waisevu Bay with our five precious water con-
tainers full to the brim, a strong wind suddenly arrived from
nowhere and instantly whipped the sea into angry whitecaps.
Ten of us were in ranger Pita Biciloa’s overloaded 18-foot fiber-

glass boat, National Trust staff, a few of us visiting researchers,
and a scattering of helpers from the village. We squatted precar-
iously around a huge mound of camping gear, boxes of food,
and now enough fresh water to last the first week on the unin-
habited Iguana Sanctuary Island of Yadua Taba.

Unlike our previous trips to Yadua Taba during the long
dry season when rain never falls, this was our first wet-season trip
and we could expect heavy tropical downpours at least several
times a week. Sure enough, as we motored the last 5 km to
Yadua Taba, a huge angry front of heavy black clouds moved
rapidly toward us, while the wind increased and the crests of the
small, sharp waves exploded over the boat’s bow to soak us all.

Luckily the high tide allowed us to motor all the way to the
beach on Yadua Taba and we quickly began unloading and mov-
ing the huge mound of gear to our campsite just inside the for-

Soaking Wet in a Fijian Dry Forest
Peter S. Harlow1 and Suzi Morrison2

1Manager, Herpetofauna Division, Taronga Zoo, Mosman, NSW, 2088, Australia (pharlow@zoo.nsw.gov.au)
2School of Botany & Zoology, Australian National University, Canberra, ACT, 0200, Australia (suzfm@yahoo.com.au)

Photographs by Peter S. Harlow unless otherwise indicated.

IGUANA  •  VOLUME 13, NUMBER 3  •  SEPTEMBER 2006 193FIJIAN DRY FOREST

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The Yadua Taba Crested Iguana sanctuary island is surrounded by coral reefs.

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est. A wall of rain could be seen a few hundred meters out to sea,
moving quickly toward us, and the rush to complete the unload-
ing increased. The gear was thrown into a pile in a central clear-
ing and covered with a large tarpaulin just as the rain struck, a
gentle roar in the forest canopy above us at first, but within sec-
onds so heavy that we had to shout to hear each other speak. We
stood around laughing, and were all totally soaked in just a few
seconds. Even if we had them, umbrellas and raincoats are use-
less in the hot tropics, so we ignored the rain and began to erect
our largest tarpaulin, which would be the center of the camp,
our kitchen, and the only dry area for eating and working.

Erecting a large plastic sheet with only one rope on each
corner would seem to be a simple proposition. This task was
clearly up to our Fijian hosts, and, even though our suggestions
were politely considered, everyone seemed to have a different
plan. A lengthy discussion that considered the pros and cons of
where, how, and when continued as the first wall of rain dimin-
ished to a steady, heavy downpour and the wind suddenly
dropped.

Since both the rain and the tarpaulin discussions could con-
tinue indefinitely, rather than stand around in the rain looking
useless and bedraggled, we headed into the forest. We were both
eager to look for signs of nesting iguanas, so we walked toward
an area that we knew had the greatest density of Crested Iguanas
(Brachylophus vitiensis).

The forest on Yadua Taba is classified as “tropical dry for-
est.” The canopy is low, usually 6–10 m. The island receives less
than 200 cm of rain per year, nearly all during the 3–4 month

194 IGUANA  •  VOLUME 13, NUMBER 3  •  SEPTEMBER 2006 HARLOW AND MORRISON

Tima, one of our field assistants, up early and making “babakau”
(Fijian fried bread) for breakfast.

A Fijian Crested Iguana watches from a low branch.

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IGUANA  •  VOLUME 13, NUMBER 3  •  SEPTEMBER 2006 195FIJIAN DRY FOREST

wet season. This dry forest plant community is the most endan-
gered in Fiji. On most islands, it has been burned and cleared
for farming, coconut plantations, or cattle and goat grazing,
while remnant patches on other islands have been overtaken by
exotic invasive plant species. Yadua Taba Island is the single
exception, and it is the only small island example of dry forest
remaining in Fiji. To add to its lucky isolation, it has no intro-
duced cats, mongooses, or exotic rat species (only the endemic
Pacific Rat, Rattus exulans), which is probably why it supports
at least 6,000 Crested Iguanas. Even the remnant grasslands and
patches of invasive plants on the ridges of Yadua Taba are revert-
ing to native forest since burning stopped in 1980 and the last
few goats were removed in 2004. The National Trust for Fiji is
carefully monitoring, poisoning, and removing the most inva-
sive of the island’s exotic plant species in an effort to maximize
the native forest available to the critically endangered iguanas.

The first obvious differences from our dry season experi-
ences in the forest were the small purple fruits and white flow-
ers of the Cevua Trees littering the ground, a carpet of tiny green
seedlings, and abundant recent soil diggings. These diggings,
however, were from land crabs, not gravid iguanas. The main
reason for our February visit was to document Crested Iguana
nesting biology, as no records document nesting in the wild for
either species of Pacific iguana. Previous field trips to Yadua Taba
in months from May to December over seven years had not

located a single gravid or nesting female. However, we had seen
hatchlings appear toward the end of November in several years
— but when and where the eggs are laid remained a mystery.
Do female Crested Iguanas migrate to communal nesting areas,
and do they guard their nest sites like many iguanas? These are
just some of the questions that Suzi wants to answer during her
Ph.D. project on the species. Because eggs laid in captivity take

The fruiting Cevua tree (Vavaea amicorum) is important in the wet sea-
son diet of Crested Iguanas on Yadua Taba Island. Only the soft and
ripe purple fruit will be selected and eaten during this season of plenty.

The authors processing captured Crested Iguanas in the forest on a dry night.

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between 6 and 9 months to hatch (depending on incubation
temperatures), and hatching starts in late November on Yadua
Taba, we assumed that nesting had to occur during the middle
of the wet season, from February to April. John Gibbons, who
described this species after first finding it on Yadua Taba in
1979, suggested that females nest between April and May, but
he never saw a nesting female.

Yadua Taba is a small (70 ha), rocky, volcanic island with
steep slopes and many cliffs. As we slipped and slid our way up
a muddy slope in the pouring rain, we were pleased to see a
ravine, which we had only seen dry, flowing like a river between
pools of fresh water. Although we were soaked to the skin, the
possibility of a regular wash was not lost on us, as on previous
dry season trips, the lack of fresh water had meant that the salty
Pacific was our only bath for weeks at a time. Perhaps our nor-
mally precious fresh water supply could be relegated to backup
for this trip.

Deep in the forest, land crab diggings are less common and,
as we walked farther, we began seeing excavations that were
more like the agamid lizard nesting burrows with which we are
familiar in Australia. Then we saw one — a fat, green, mud-cov-
ered Crested Iguana frozen to the ground, watching us, a neat
burrow at her snout, and a pile of muddy soil at her side. She
was heavily gravid, the eggs could be seen as large lumps inside

her. We stood in silence, certainly not the first to observe this,
but knowing that we were the first to record it. We marked the
site with colored tape and left quietly, hoping not to disturb her
nesting. In less than half an hour on the island, we had found
what we had come to see.

The next day, as the rain continued and we began to rem-
inisce fondly of the dry season, we returned to that same site.

196 IGUANA  •  VOLUME 13, NUMBER 3  •  SEPTEMBER 2006 HARLOW AND MORRISON

Suzi and Mata in the village on nearby Yadua Island.

The first Crested Iguana nest located; excavated to show the three large
eggs.

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IGUANA  •  VOLUME 13, NUMBER 3  •  SEPTEMBER 2006 197FIJIAN DRY FOREST

The female and the burrow were gone, the site camouflaged to
look like it had never been disturbed. We carefully excavated the
soil with a spoon, took measurements and photos, added a tiny
temperature data-logger to the clutch of three huge eggs, and
refilled the nesting burrow. In the weeks that followed, as our
never-to-dry-again T-shirts slowly rotted off our backs with the
continued rain, we found another 13 nests.

Surprisingly, many other aspects of the Crested Iguana’s biol-
ogy also remain unknown, mostly because of the remoteness of
Yadua Taba and the expense and difficulty of working there.
Yadua Taba is not open to the public, and only researchers are
issued permits to visit. With the exception of a visiting U.S.
botanist, the last foreign visitors before us were the IUCN Iguana
Specialist Group, who visited for one day in November 2004
after their annual meeting in Suva, Fiji’s capital. For most of the
year, the island remains solely the realm of the iguanas, inter-
rupted only by short visits of the National Trust ranger, Pita, to
monitor invasive plant species and patrol for uninvited guests.

Crested Iguanas probably will be translocated from Yadua
Taba to other iguana-free islands in Fiji in the next few years.
Before this can happen, however, we need to understand not just
their breeding biology, but a host of other important ecological

attributes such as diet, population dynamics, and basic biology.
The information from this field season, added to the growing
knowledge base on the biology and habitat requirements of
Crested Iguanas, will be integral to future reintroduction or
translocation efforts. In November of this year, we will return to
Yadua Taba to witness the emergence of hatchlings from the
monitored nests. Knowing a little more this time of what to
expect from a wet season in a dry forest, we’ll be sure to bring
along a few spare T-shirts!

Suggested Reading
Gibbons, J.R.H. 1981. The biogeography of Brachylophus (Iguanidae) includ-

ing the description of a new species, B. vitiensis, from Fiji. Journal of
Herpetology 15:255–273.

Gibbons, J.R.H. 1984. Iguanas of the South Pacific. Oryx 18:82–91.

Gibbons, J.R.H. and I.F. Watkins. 1982. Behavior, ecology, and conservation
of South Pacific iguanas, Brachylophus, including a newly discovered
species, pp 419–441. In G.M. Burghardt and A.S. Rand (eds.), Iguanas
of the World: Their Behavior, Ecology and Conservation. Noyes Publ., Park
Ridge, New Jersey.

Harlow, P.S. and P.N. Biciloa. 2001. Abundance of the Fijian Crested Iguana
(Brachylophus vitiensis) on two islands. Biological Conservation 98:223–231.

Harlow, P.S. 2004. Lost in the South Pacific: The Pacific Iguanas (Genus
Brachylophus). Iguana 11:198–205.

Suzi explaining to the children in the village on Yadua why she is working on Crested Iguanas on Yadua Taba.

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