Long‐term within‐season changes in the diet of Common Guillemot Uria aalge chicks at a North Sea colony: implications for dietary monitoring
Long‐term within‐season changes in the diet of Common Guillemot
Uria aalge
chicks at a North Sea colony: implications for dietary monitoring
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北海群体海鸠幼鸟饮食的长期季节内变化：对饮食监测的影响
作者：
M. Harris;S. Albon;M. Newell;Carrie Gunn;F. Daunt;S. Wanless
在过去的四十年（1982-2019）中，在常见的Guillemoturia aalgechick饮食中，关键猎物物种（Lesser SandeelAmmodytes marinus）的比例在季节内发生了明显的变化。随着山鸡的数量越来越少，它们的出现主要局限于雏鸟时期的早期。因此，如果采样发生在很短的时间窗口内，特别是如果这是在赛季的早期或晚期，桑德尔的平均年比例估计不佳。在饮食监测中很少考虑季节内的变化，但我们的结果强调需要对其他物种和地点进行进一步分析，以更深入地了解如何最好地优化采样方案。
Over four decades (1982–2019) there were pronounced within‐season changes in the proportion of a key prey species (Lesser SandeelAmmodytes marinus) in Common GuillemotUria aalgechick diet. As Sandeels became scarcer their occurrence was largely confined to the early part of the chick period. Consequently, the mean annual proportion of Sandeels was poorly estimated if sampling occurred within a short time window, particularly if this was early or late in the season. Within‐season variation is rarely considered in diet monitoring but our results highlight the need for further analyses across other species and sites to develop a deeper understanding of how best to optimize sampling protocols.