Meeting Abstract
While reptiles are commonly considered solitary animals, they can have complex social interactions in nature. This has been confirmed by observed adverse behavioral changes in reptiles housed individually when in captivity. However, few studies have examined the true physiological consequences of this practice. In this study, we tested how being housed with and without conspecifics caused physiological changes, including circulating corticosterone and reproductive hormone concentrations, and bactericidal ability in male and female side-blotched lizards (Uta stansburiana). While there were no significant physiological changes in females, we found that males housed alone had significantly higher corticosterone concentrations, and that males housed with a female had higher testosterone levels. In addition, males housed in pairs had relatively reduced immune function when compared to individually housed males. The difference among sexes may be due to the stronger territoriality males exhibit when compared to females. Our results suggest that individually housing male reptiles might be stressful, and that males group-housed with female conspecifics maintain higher levels of testosterone indicative of better reproductive function. This group housing is not without cost, however, as animals with elevated testosterone also show reduced immune ability. As both scenarios may be adverse or beneficial to an animal, research and animal husbandry facilities must take these physiological changes into consideration when determining housing regimes for reptiles.
