The Diet of the Hispaniolan Snake Antillophis parvifrons (Colubridae)

Abstract

Snakes of the xenodontine colubrid genus Antillophis occur on Cuba, several of its satellite islands (A. andreae), and on Hispaniola and many of its satellite islands (A. parvifrons); in addition, a single specimen of A. parvifrons has been taken on Little Inagua Island in the Bahamas (Schwartz and Thomas, 1975). Both species of Antillophis are geographically and ecologically widespread and have differentiated into a number of subspecies (six in A. andreae and nine in A. parvifrons). Antillophis parvifrons is the most widespread (rivaled only by the arboreal Uromacer catesbyi) and abundant species of colubrid on Hispaniola. It is one of the smallest Hispaniolan colubrids: mean snout-vent length (SVL) in our sample was 366 ? 6 mm (range 153-557), and it is similar to some North American garter snakes (Thamnophis) in general habitus. Antillophis parvifrons is an active forager that is diurnal and ground-dwelling. It is ubiquitous in habitat, ranging from lush tropical forest to xeric scrub. It has been taken at altitudes from sea level to 1708 m (Schwartz, 1980). The most recent taxonomic review is that by Thomas and Schwartz (1965); Maglio (1970) discussed skull morphology, zoogeography and origin. Photographs of juvenile and adult A. parvifrons appear in Sajdak and Henderson (1982); a photograph of an adult A. andreae appears in Schwartz and Henderson (1985). Despite its wide distribution and relative abundance on Hispaniola, little is known about the natural history of A. parvifrons. Franz and Gicca (1982) provided information on diet and reproduction for a collection of snakes from Ile de la Gonave, Haiti; and Sajdak and Henderson (1982) added a note on clutch size, description of hatchlings and defensive behavior for animals from Isla Saona, Dominican Republic. In this paper, we present information on the diet of A. parvifrons based on examination of 649 specimens, and discuss diet in terms of foraging mode, prey size, relative prey abundance, and geography. Five hundred and sixty specimens of Antillophis parvifrons from three collections were necropsied at the Milwaukee Public Museum, and we have incorporated the results of the necropsy of 89 specimens by Franz and Gicca (1982). Specimens from collections at the American Museum of Natural History (AMNH), the Museum of Comparative Zoology at Harvard University (MCZ), and the Milwaukee Public Museum (MPM) were examined; the Franz and Gicca material is stored at the Florida State Museum at the University of Florida (FSM). Details of methods used for necropsies and determination of prey volumes appear elsewhere (Henderson 1982, 1984a). The Antillophis were collected throughout the year at many localities throughout Hispaniola (including satellite islands) over a span of about 70 years. We compared snake size (SVL), prey size and diet composition for five localities/regions. Localities in Haiti were: 1) Dept. Sud: St. Croix; (N = 14 specimens/ 8 prey items) 2) Dept. L'Ouest: Tiote (11/8) and 3) Savane Zombi; (12/12) 4) Ile de la Gonave (several sites) (22/6); 5) we lumped specimens from several localities in the Barahona Peninsula of the Dominican