The Herpetofauna of the Islas de la Bahia, Honduras

Abstract

After a brief description of the Bay Islands' position, physiography, geology, vegetation, and previous work done there, the 35 species of reptiles and amphibians known from the Bay Islands are discussed with, where pertinent, their morphological variation, taxonomic relationships, and habitat preferences. No island subspecies are recognized and the names Cnemidophorus lemniscatus ruatanus, Leptotyphlops phenops magnamaculata, Elaphe flavirufa polysticha, and Tretanorhinus nigroluteus dichromaticus are placed in synonymy. No consistent pattern of increase in average numbers of ventrals over those of the adjacent mainland, such as is evident on certain other islands, occurs in the snakes of the Bay Islands. The Bay Island herpetofauna is arranged into three assemblages on the basis of present-day distributions; an endemic assemblage (4 species), a West Indian assemblage (2 species), and a mainland Honduran assemblage (29 species). Three of the endemic species are related to mainland counterparts and one to West Indian counterparts. Of the mainland Honduran assemblage, 8 species are widespread geographically, ecologically, and altitudinally, 4 species occur in dry ecological formations, 1 is restricted to coastal situations, and 16 occur in wet ecological formations. Species that have colonized the Bay Islands are widespread ecologically and geographically, are relatively abundant, or inhabit "weed" habitats, or exhibit a combination of these features. The species compositions of the herpetofauna of the three major islands of the Bay Island group are distinctive and nonrecurrent and are largely depauperate reflections of the mainland herpetofauna. Colonization of the Bay Islands appears to have been effected by fortuitous, over-water dispersal. Inter-island dispersal has probably been largely limited to movements between islands. A gazetteer of specimen localities is appended.