Cortés Pablo Andrés, Petit Magali, Lewden Agnès, Milbergue Myriam, Vézina François
Instituto de Ciencias Ambientales y, Facultad de Ciencias, Universidad Austral de Chile Campus Isla Teja, Valdivia, Chile.
J Exp Zool A Ecol Genet Physiol. 2015 Mar;323(3):179-90. doi: 10.1002/jez.1908. Epub 2015 Feb 17.
Resident passerines inhabiting high latitude environments are faced with strong seasonal changes in thermal conditions and energy availability. Summit metabolic rate (maximal metabolic rate elicited by shivering during cold exposure: M(sum)) and basal metabolic rate (BMR) vary in parallel among seasons and increase in winter due to cold acclimatization, and these adjustments are thought to be critical for survival. Wintering individuals expressing consistently higher M(sum) and BMR could therefore be seen as better performers with higher chances of winter survival than those exhibiting lower metabolic performance. In this study, we calculated repeatability to evaluate temporal consistency of body mass, BMR and M(sum) within and across three consecutives winters in black-capped chickadees (Poecile atricapillus). We found that body mass was significantly repeatable both within and across winters (R 0.51-0.90). BMR (R 0.29-0.47) was only repeatable within winter while M(sum) was repeatable both among (R 0.33-0.49) and within winters (R 0.33-0.49) with the magnitude and significance of repeatability in both variables depending on the year and whether they were corrected for body mass or body size. The patterns of repeatability observed among years also differed between the two variables. Our findings suggest that the relative ranking of individuals in winter metabolic performance is affected by local ecological conditions and can change within relatively short periods of time.
栖息在高纬度环境中的留鸟雀形目鸟类面临着热条件和能量供应的强烈季节性变化。最高代谢率（冷暴露期间颤抖引发的最大代谢率：M(sum)）和基础代谢率（BMR）在不同季节中平行变化，并由于冷适应在冬季增加，这些调节被认为对生存至关重要。因此，与那些代谢表现较低的个体相比，冬季持续表现出较高M(sum)和BMR的个体可以被视为表现更好、冬季生存机会更高的个体。在本研究中，我们计算了重复性，以评估黑头山雀（Poecile atricapillus）在三个连续冬季内及不同冬季间体重、BMR和M(sum)的时间一致性。我们发现，体重在冬季内和不同冬季间都具有显著的重复性（R 0.51 - 0.90）。BMR（R 0.29 - 0.47）仅在冬季内具有重复性，而M(sum)在不同冬季间（R 0.33 - 0.49）和冬季内（R 0.33 - 0.49）都具有重复性，这两个变量重复性的大小和显著性取决于年份以及它们是否根据体重或体型进行了校正。在不同年份观察到的重复性模式在这两个变量之间也有所不同。我们的研究结果表明，个体在冬季代谢表现中的相对排名受当地生态条件影响，并且可能在相对较短的时间内发生变化。
