%0 Journal Article
%T Climate-Related Variation in Body Dimensions within Four Lacertid Species
%A Stanislav Volynchik
%J International Journal of Zoology
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/795387
%X A close relationship between habitat and external morphology is widespread among many animals, including reptiles. Here, I studied the relationship between abiotic environmental conditions and body size of four lacertid species (Phoenicolacerta laevis, Ophisops elegans, Acanthodactylus boskianus, and Mesalina guttulata) occurring in Israel. I examined the effect of average annual temperature and average annual precipitation on body and limb dimensions, using linear statistical models. Temperature- and precipitation-related geographic clines in body size showed the same trend among all species. Females displayed stronger phenotypic response to temperature gradient than conspecific males, suggesting a sex-specific effect of natural selection. Snout-vent length (SVL) was negatively correlated with temperature, supporting BergmannĄ¯s rule in O. elegans and in female P. laevis and A. boskianus, but not in M. guttulata. Precipitation was positively related to SVL in O. elegans and M. guttulata, and in female P. laevis and A. boskianus. The relative extremity lengths, especially hind limb segments, generally increase towards hot and dry locations, following AllenĄ¯s rule. Among the Mediterranean region species (P. laevis, O. elegans) the morphological-environmental link with temperature was stronger than in desert dwellers (A. boskianus, M. guttulata), for which precipitation was the major determinant of spatial variation. 1. Introduction Latitudinal variation in corporeal dimensions has often been explained as a response to temperature gradients, which are strong predictors of animalsĄ¯ external morphology. Zoogeographic principles such as BergmannĄ¯s and AllenĄ¯s rules, in classical (thermal) interpretation, express the relationship between body size or shape and environmental temperature [1]. Therefore, the most renowned and generally accepted explanation for these rules is based on the heat-conservation hypothesis [2¨C4]: reduced surface area-to-volume ratio provides better heat retention in order to reduce body heat loss at low temperatures (BergmannĄ¯s rule). Bergmann [5] stated that in cooler climates, large-bodied endotherms, with a low body surface area to body volume ratio (i.e., a greater thermal inertia), typically retain body heat better than smaller ones. Similar principles contributing to reduce heat loss underlie AllenĄ¯s rule [6], which predicted that animals living in colder environments tend to have shorter protruding body parts, such as ears, tails, and limbs. Furthermore, several authors [7, 8] have shown that the geographical intraspecific
%U http://www.hindawi.com/journals/ijz/2014/795387/