Diet preferences as the cause of individual differences rather than the consequence

Behavioural variation within a species is usually explained as the consequence of individual variation in physiology. However, new evidence suggests that the arrow of causality may well be in the reverse direction: behaviours such as diet preferences cause the differences in physiological and morphological traits. Recently, diet preferences were proposed to underlie consistent differences in digestive organ mass and movement patterns (patch residence times) in red knots (Calidris canutus islandica). Red knots are molluscivorous and migrant shorebirds for which the size of the muscular stomach (gizzard) is critical for the food processing rate. In this study, red knots (C. c. canutus, n = 46) were caught at Banc d'Arguin, an intertidal flat ecosystem in Mauritania, and released with radio-tags after the measurement of gizzard mass. Using a novel tracking system (time-of-arrival), patch residence times were measured over a period of three weeks. Whether or not gizzard mass determined patc...

物种内的行为变异通常被解释为个体生理差异的结果。然而，新证据表明因果关系的方向很可能相反：饮食偏好等行为会导致生理及形态特征的差异。近期研究提出，饮食偏好是红腹滨鹬（Calidris canutus islandica）消化器官质量与移动模式（斑块停留时间）持续差异的潜在机制。红腹滨鹬为食软体动物的迁徙滨鸟，其肌胃（gizzard）的大小对食物处理速率至关重要。本研究中，于毛里塔尼亚的潮间带平原生态系统阿尔金滩（Banc d'Arguin）捕获红腹滨鹬（C. c. canutus，n=46），测量肌胃质量后为其佩戴无线电标签并释放。采用新型追踪系统（到达时间法，time-of-arrival），在三周内测定斑块停留时间。肌胃质量是否决定斑块...