دانلود رایگان مقاله بازتاب استرس حاد استراتژی مقابله واگرا در گیاهخوار بزرگ

Abstract

Individuals differ in the manner that they cope with risk. When these behavioral differences are manifested in risky or challenging environments (i.e. stressful situations), they are generally interpreted within the “coping style” framework. As studying inter-individual variability in behavior is particularly challenging in the wild, we used a captive facility to explore consistency in the individual behavioral response to an acute stress in roe deer (Capreolus capreolus). Using behavioral and physiological parameters measured six times across a calendar year, we first quantified individual repeatability and, second, explored the correlations among these parameters that might indicate a coherent stress response. Finally, we analyzed the link between the stress response and individual body mass, a reliable indicator of phenotypic quality in roe deer. We found that the measured parameters were highly repeatable across seasons, indicating that the individual stress response is consistent over time. Furthermore, there was considerable covariation among the stress response parameters, describing a proactivity-reactivity gradient at the individual level. Finally, proactive individuals had higher body mass than reactive individuals. We suggest that consistent individual differences in energy metabolism and physiology may promote consistent individual differences in behavioral traits, providing a mechanistic link between food acquisition tactics and demographic performance.

4. Discussion

Our overall aim was to quantify inter-individual variation in the stress response in captive roe deer and to explore the link between this variation and individual condition or quality. Firstly, we showed that the four stress response parameters, rectal temperature, behavioral score, hematocrit level and N/L ratio, were all highly repeatable across seasons, indicating that the stress response of individuals appears to be consistent over time. From a meta-analysis, Bell et al. (2009) reported that behavioral traits are generally repeatable, with an average value of 0.37, whereas the repeatability of our behavioral score was substantially higher (r = 0.61, 95% confidence of interval = [0.365, 0.790]). Published information on the repeatability of other stress parameters is scarce (Biro and Stamps, 2010; Szafranska et al., 2007). For instance, although a stress-induced rise in temperature has been extensively studied on model organisms in controlled environments (Cabanac and Guillemette, 2001; Cabanac, 1975; Carere and van Oers, 2004; Moe and Bakken, 1997), consistency in this parameter was only clearly demonstrated recently in eastern chipmunks (Tamias striatus, Careau et al., 2011). I