Sex-specific microhabitat use is associated with sex-biased thermal physiology in Anolis lizards [RESEARCH ARTICLE]

We examined microhabitat use and thermal physiology in two ectothermic congeners that are ecologically similar but differ in their degree of sexual size dimorphism. Brown anoles (Anolis sagrei) exhibit male-biased sexual size dimorphism and live in thermally heterogeneous habitats, whereas slender anoles (Anolis apletophallus) are sexually monomorphic in body size and live in thermally homogeneous habitats. We hypothesized that differences in habitat use between the sexes would drive sexual divergence in thermal physiology in brown anoles, but not slender anoles, because male and female brown anoles may be exposed to divergent microclimates. We found that male and female brown anoles, but not slender anoles, used perches with different thermal characteristics and were sexually dimorphic in thermal tolerance traits. However, field-active body temperatures and behavior in a laboratory thermal arena did not differ between females and males in either species. Our results suggest that sexual dimorphism in thermal physiology can arise from phenotypic plasticity or sex-specific selection on traits that are linked to thermal tolerance, rather than from direct effects of thermal environments experienced by males and females.

Source: Journal of Experimental Biology - January 22, 2021 Category: Biology Authors: Logan, M. L., Neel, L. K., Nicholson, D. J., Stokes, A. J., Miller, C. L., Chung, A. K., Curlis, J. D., Keegan, K. M., Rosso, A. A., Maayan, I., Folfas, E., Williams, C. E., Casement, B., Gallegos Koyner, M. A., Padilla Perez, D. J., Falvey, C. H., Alexan Tags: RESEARCH ARTICLE Source Type: research