Friday's Findings - October 1 2021

Release Date:

Glucocorticoid hormones associated with reduced White-tailed deer fawn survival

Date: October 1, 2021 from 2-2:30 p.m. eastern time

Speakers: Tess Gingery, PA Cooperative Fish and Wildlife Research Unit, Pennsylvania State University; Duane R. Diefenbach, U.S. Geological Survey, , PA Cooperative Fish and Wildlife Research Unit, Pennsylvania State University

Image: White-Tailed Deer (Odocoileus virginianus)

White-tailed deer in a field. (Credit: John J. Mosesso, USGS. Public domain.)

 

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ID: 218853016#   

 

Summary: It is unknown how ungulate physiological responses to environmental perturbations influence overall population demographics. Moreover, neonatal physiological responses remain poorly studied despite the importance of neonatal survival to population growth. Glucocorticoid (GC) hormones potentially facilitate critical physiological and behavioral responses to environmental perturbations. However, elevated GC concentrations over time may compromise body condition and indirectly reduce survival. We evaluated baseline salivary cortisol (CORT; a primary GC in mammals) concentrations in 19 wild neonatal white-tailed deer (Odocoileus virginianus) in a northern (NS) and southern (SS) area in Pennsylvania. After ranking survival models consisting of variables hypothesized to influence neonate survival (i.e. weight, sex), the probability of neonate survival was best explained by CORT concentrations, where elevated CORT concentrations were associated with reduced survival probability to 12 weeks of age. Cortisol concentrations were greater in the SS where predation rates and predator densities were lower. As the first evaluation of baseline CORT concentrations in an ungulate neonate to our knowledge, this is also the first study to demonstrate CORT concentrations are negatively associated with ungulate survival at any life stage. Glucocorticoid hormones could provide a framework in which to better understand susceptibility to mortality in neonatal white-tailed deer.