Bedford Tom, Oliver Caitlin Jade, Andrews Clare, Bateson Melissa, Nettle Daniel
Centre for Behaviour and Evolution & Institute of Neuroscience, Newcastle University, Newcastle, UK.
Anim Behav. 2017 Jun;128:51-60. doi: 10.1016/j.anbehav.2017.03.026.
Dominance in socially foraging animals may be related to sex and to variation in individual quality. Individual quality may in turn reflect conditions during early development. We studied dominance in a cohort of adult European starlings, , that had been subject to experimental manipulations of food supply and begging effort when they were nestlings. We measured dominance in two different contexts, contests over a food resource and relative position on a sloping perch, over the course of 3 weeks. Dominance in food contests was extremely stable over the 3 weeks and relative perch position somewhat stable. Males were dominant over females in contests over food and perched in higher positions. These sex differences were not explained by males' greater size or body weight. Food dominance and perch position were uncorrelated. Neither early life food supply nor early life begging effort affected food dominance; nor did an alternative measure of developmental stress, developmental telomere attrition. Birds that had been made to beg more as nestlings perched in higher positions than those that had begged less. Our results did not support the hypothesis that early life adversity leads to lower adult dominance rank in the context of feeding, and we suggest that relative perch position may have measured individual preference rather than competitive ability.
在社会性觅食动物中,优势地位可能与性别以及个体质量的差异有关。个体质量反过来可能反映早期发育期间的状况。我们研究了一群成年欧洲椋鸟的优势地位,这些椋鸟在雏鸟时期曾接受过食物供应和乞食努力的实验性操控。在3周的时间里,我们在两种不同情境下测量优势地位,即争夺食物资源的竞争以及在倾斜栖木上的相对位置。食物竞争中的优势地位在3周内极其稳定,栖木上的相对位置则略显稳定。在食物竞争中,雄性比雌性更具优势,且栖息在更高的位置。这些性别差异并不能用雄性更大的体型或体重来解释。食物优势地位与栖木位置不相关。早期生活中的食物供应和早期生活中的乞食努力都不会影响食物优势地位;发育应激的另一种衡量指标——发育过程中的端粒损耗——也不会产生影响。与乞食较少的雏鸟相比,那些在雏鸟时期被迫更多乞食的鸟栖息在更高的位置。我们的研究结果并不支持早期生活逆境会导致成年后在觅食情境中优势等级较低这一假设,并且我们认为栖木上的相对位置可能衡量的是个体偏好而非竞争能力。