The Central American Herpetofauna: An Ecological Perspective

Abstract

Six major herpetological habitats (biociations) are recognized in Central America; these are based principally on the physiognomic characteristics of the vegetation. There are three tropical habitats (evergreen forest, scrub forest, and savanna) and three montane habitats (cloud forest and low montane wet forest, oak-pine forest, and alpine and subalpine habitats including fir forest, pine-cypress forest, and montane meadows). Temperature and moisture are the principal environmental factors affecting the distributions of amphibians and reptiles in Central America. Secondarily, cover in the form of shade or mulch, and suitable breeding sites are significant factors determining the distribution of species. Five major ecological assemblages are defined in the Central American herpetofauna; characteristic species are noted in each, and the geographical distribution of each assemblage is described. The humid tropical and arid tropical assemblages contain the largest numbers of species and are widespread in the lowlands. The humid montane assemblage is characterized by a high degree of local endemism and inhabits cloud forest and low wet forest in the mountainous regions. The arid montane assemblage consists of an impoverished fauna inhabiting oak-pine forests, and the high montane assemblage is made up of a few species living in the alpine and subalpine habitats. A geographical analysis shows that a greater continuity exists in the lowland than in the montane assemblages; the latter often more closely resemble assemblages in the adjacent lowlands than in geographically remote highlands and characteristically exhibit a higher degree of local endemism than the lowland faunas. Climatic fluctuations in the Pleis-