Meeting Abstract

P1.186  Friday, Jan. 4  It’s About Time: Chelonian Physiological Ecology and Conservation HENEN, BT; United States Marine Corps bthenen@yahoo.com

Rate phenomena are central measures of the physiological and ecological exaptations and adaptations of many vertebrate endotherms and ectotherms. For Agassiz’s Desert Tortoises, Gopherus agassizii, physiological and ecological rates help demonstrate advantages of ectothermy in a harsh, variable environment, and vulnerability on a conservation timescale. The ability to temporally relax or abandon homeostasis with regards to osmoregulation, body condition, metabolic rate, and water flux helps them endure short or extended droughts in their desert clime. Their morphology, behavior, and physiology, including follicular atresia and long-term vitellogenesis, support their long, iteroparous lives and a bet-hedging reproductive strategy. However, this combination makes them less than ideal ‘canaries in the coal mine’ or indicators of habitat quality and degradation. Their ability to persist and reproduce for long periods under harsh conditions and degraded landscapes, at individual and population levels, suggest that range-wide declines for G. agassizii portend considerable habitat degradation and community and biodiversity loss. The physiological and ecological rate phenomena, including the slow reproduction and low juvenile survivorship of G. agassizii and other chelonians, indicate that these species require extended periods to recover from anthropogenic-based threats.