Meeting Abstract
In several avian and amphibian species, GC regulation varies such that individuals living at range edges maintain different levels in circulation than individuals living at the core of a range. These patterns are thought to arise because GCs can regulate traits important to success at different parts of a range. Here, we queried whether introduction history (i.e., whether a species was native or non-native) and location within the native range (i.e., edge versus core versus the intervening area) predicted baseline and post short-term restraint GC levels. To detect the presence of relationships, we used HormoneBase, a repository of much of the published GC data from wild vertebrates. In birds and reptiles, baseline GCs were lower in non-native than native species, although in the latter group, these effects were more pronounced in females than males. In native species, location of capture within a range also predicted GC regulation. Here though, directionality appeared to vary with taxon and sex such that no clear pattern emerged. Presently, we are assessing to what extent phylogeny (at finer levels) influences our results; many of the non-native data are available for only a few species. Nevertheless, our work further suggests that GC regulation affects the distribution of organisms, perhaps by influencing which individuals survive at the time of introduction.
