Long-term elevation of indicators of physiological stress in captive garter snakes

SPARKMAN, A. M.; PALACIOS, M. G.; BRONIKOWSKI, A. M.

San Francisco

Congreso; Annual Meeting of the Society for Integrative and Comparative Biology Meeting; 2013

Society for Integrative and Comparative Biology

The physiological response to captive stress varies among species, with some adapting quickly to captive environments, but others adjusting slowly or exhibiting long-term deviation from baseline patterns in the wild. To evaluate the effects of captivity on any given species, it is essential to compare captive measures with measures taken in the wild. We tested for hematological indicators of captive stress in juvenile and adult western terrestrial garter snakes, Thamnophis elegans . We measured baseline plasma corticosterone and heterophil to lymphocyte (H:L) ratios in both juvenile and adult snakes upon capture in the field, and in adult females after one and three months in captivity. Corticosterone and H:L ratios were also measured at three and thirteen months of age in captive-born offspring of wild-caught females. Interestingly, while corticosterone levels were strongly positively correlated to H:L ratios in the field, the relationship between the two disappeared over time spent in captivity, and was not present in juveniles born in captivity. Longitudinal samples of adult females showed higher levels of both corticosterone and H:L ratios in captivity than in the field; both variables were at their highest levels after three months in captivity. Offspring corticosterone and H:L ratios were also significantly higher than a mixed-age sample of animals in the field. Our findings suggest that captivity has long-term consequences for physiological indices of stress in Thamnophis elegans , and that these consequences are manifest in both wild-born and captive-born individuals.