Functional and population responses of the lizard Cnemidophorus tigris to environmental fluctuations

Abstract

SYNOPSIS. An understanding of the ecology of a species depends upon knowing the eifects of an array of biotic and abiotic environmental variations on individuals. Population patterns are determined by the collective responses of individuals to environmental variation. Moreover, each individual, age class, size class, and both sexes may have a unique array of abilities. Therefore, it should be an imperative to focus on autecologyas a mechanistic foundation of population and community ecology and conservation biology. The autecology of the western whiptail lizard, Cnemidophoru tigris (Teiidae)-an abundant and tractable species-was examined in the Sonoran desert of southern California for eight years. Spring-to-summer changes in the spatial and temporal patterns of foraging in adult C. tigris were related to arthropod distribution and abundance. Moreover, year-to-year variation in rainfall and plant productivity influenced (1) arthropod abundance and (2) the patterns of behavior, growth, and reproduction of C. tigris. Changes in the population size of C. tigris also were closely related to environmental variation. The perspective of a multi-year study may provide enough knowledge of a species to enable one to anticipate and perhaps, obviate the consequences of impending anthropogenic disturbance for that species, other members of the biological community, and its congeners in other biological communities ©1994 by the American Society of Zoologists.