Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, Pennsylvania, USA.
U. S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, Pennsylvania, USA.
Integr Zool. 2021 Mar;16(2):214-225. doi: 10.1111/1749-4877.12499. Epub 2020 Nov 26.
It is unknown how ungulate physiological responses to environmental perturbation 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.
目前尚不清楚有蹄类动物对环境干扰的生理反应如何影响其总体种群动态。此外，尽管新生儿的存活对种群增长很重要，但新生儿的生理反应仍然研究甚少。糖皮质激素（GC）可能有助于对环境干扰做出关键的生理和行为反应。然而，随着时间的推移，GC 浓度的升高可能会损害身体状况，并间接降低存活率。我们评估了宾夕法尼亚州北部（NS）和南部（SS）地区 19 只野生新生白尾鹿（Odocoileus virginianus）的基础唾液皮质醇（CORT；哺乳动物中的主要 GC）浓度。在对假设影响新生儿存活率的变量（即体重、性别）的生存模型进行排名后，CORT 浓度最能解释新生儿的存活率，其中 CORT 浓度升高与 12 周龄时的存活率降低有关。在 SS 地区，捕食率和捕食者密度较低，CORT 浓度较高。这是我们所知的对有蹄类动物新生儿基础 CORT 浓度的首次评估，也是首次表明 CORT 浓度与任何生命阶段的有蹄类动物存活率呈负相关的研究。糖皮质激素可能为更好地了解新生白尾鹿的死亡率易感性提供一个框架。
