GROWTH IN SONORAN DESERT POPULATIONS OF THE COMMON CHUCKWALLA (SAUROMALUS OBESUS)

摘要

The common cliuckwalla, Sauromalus obe-sus (= ater; Hollingsworth 1998), is a large, herbivorous lizard found throughout the Sonoran and Mojave Deserts of the southwestern United States and northwestern Mexico (Hollingsworth 1998). Throughout their range chuckwallas are limited to rocky outcrops typically associated with isolated mountain ranges, probably because of their unique antipredator behavior whereby they retreat into rock crevices and inflate their bodies to prevent removal by predators (Berry 1974, Hollingsworth 1998). Population subdivision resulting from their patchy distribution might be expected to lead to genetic (Lamb et al. 1992) or morphological (Hamilton 1995) variation. Although dietary (Johnson 1965, Nagy 1973) and life history (Abts 1987) investigations have been conducted for chuckwalla populations in California, Arizona populations remain little known (but see Prieto and Sorenson 1977, Prieto and Ryan 1978).