Iguana 11.3 b&w text


IGUANA  •  VOLUME 11, NUMBER 3  •  SEPTEMBER 2004 147SPECIES PROFILE

S P E C I E S  P R O F I L E

Among West Indian snakes, only the Dwarf Boas (Tropidophis)
and the Blind Snakes (Typhlops) are represented by more

species than the Racers (Alsophis). Racers are variable in color and
pattern and members of the same species may look quite differ-
ent on different islands. In the Lesser Antilles, home to five species
of Alsophis, each is found on only one or a few islands. Alsophis
antillensis is the most widely distributed, occurring on the
Monserrat, Guadeloupe, and Dominica island banks. Alsophis
rijgersmaei is found on the main islands of the Anguilla Bank, A.
rufiventris on the Saba and St Christopher (St. Kitts) banks, A.
antiguae on the Antigua Bank, and A. sanctonum on the Isles des
Saintes Bank near Guadeloupe. The introduced Mongoose
(Herpestes javanicus) poses a threat to most species of Racers on
one or more islands, and several populations have been extirpated.
The Red-bellied or Black Racer, A. rufiventris, for example, has
been extirpated from Nevis and St. Kitts, and occurs today only
on mongoose-free Saba and St. Eustatius (Statia).

On Saba and Statia, Alsophis rufiventris is widely distributed.
It is a habitat generalist, found in disturbed and natural areas from
near sea level to some of the highest elevations on these islands. It
has been observed on the rim of The Quill at an elevation of 550
m on Statia, and within 30 m of the 864-m top of Mount Scenery
on Saba. On St. Eustatius, this snake is most commonly encoun-
tered in shaded, rocky areas, which also harbor the densest popu-
lations of Anolis schwartzi, the predominant prey of A. rufiventris
on Statia.

Like other members of the genus, Alsophis rufiventris is an
actively foraging diurnal predator. Although primarily terrestrial,
it sometimes ascends into shrubs and trees. Observations on Statia
indicate that it spends roughly half of its time moving, with about
half of that time spent searching for prey in leaf litter, under dead-
fall, or in the abundant crevices of rock piles. Once a prey item
has been seized, the snake may inject a weak venom to subdue its
victim. Alsophis rufiventris is a non-aggressive species that rarely
bites. Even if it does, it is generally considered to be harmless, as
its venom infrequently elicits even mild reactions in humans. Like
all other species of Alsophis, the Red-bellied Racer is oviparous, but
little else is known about its reproduction.

References
Breuil, M. 2002. Histoire naturelle des Amphibiens et Reptiles terrestres

de l’archipel Guadeloupéen. Guadeloupe, Saint-Martin, Saint-
Barthélemy. Patrimoines Naturels 54: 1–339.

Censky, E.J. and H. Kaiser. 1998. Lesser Antillean herpetofauna, pp.
181–221. In: B.I. Crother (ed.), Caribbean Amphibians and
Reptiles. Academic Press, San Diego.

Heinz, H.M., A.J. Maley, A.Z. Savit, R.W. Henderson, and R. Powell.
2004. Behaviour and time allotment in the West Indian Snake
Alsophis rufiventris (Colubridae). Herpetol. Bull. (89): in press.

Henderson, R.W. and R.A. Sajdak. 1986. West Indian Racers: disap-
pearing act or a second chance? Lore 36: 13–18. 

Henderson, R.W. and R.A. Sajdak. 1996. Diets of West Indian Racers
(Colubridae: Alsophis): composition and biogeographic implica-
tions, pp. 327–338. In: R. Powell and R.W. Henderson (eds.),
Contributions to West Indian Herpetology: A Tribute to Albert
Schwartz. SSAR Contrib. Herpetol., vol. 12. Ithaca, New York.

Sajdak, R.A. and R.W. Henderson. 1991. Status of West Indian racers
in the Lesser Antilles. Oryx 25: 33–38.

Schwartz, A. and R.W. Henderson. 1991. Amphibians and Reptiles of the
West Indies: Descriptions, Distributions, and Natural History. Univ.
Florida Press, Gainesville.

Red-bellied Racer (Alsophis rufiventris)
Abigail J. Maley

Ohio Wesleyan University, Delaware, Ohio

Adult Alsophis rufiventris from St. Eustatius (top) and from Saba.
Photographs by John S. Parmerlee, Jr.