Beauchamp Guy
Faculty of Veterinary Medicine, University of Montreal, PO Box 5000, St-Hyacinthe, Québec, Canada J2S 7C6.
Biol Lett. 2009 Feb 23;5(1):9-11. doi: 10.1098/rsbl.2008.0490.
Individuals in groups are often thought to scan their surroundings for threats independently of one another. Models, however, suggest that foragers should monitor the vigilance level of their neighbours to prevent cheating, and to gather information about incipient predation risk. Evidence for monitoring of vigilance is scant. Here, I examined changes in vigilance levels in sleeping gulls (Larus sp.) surrounded by neighbours in various states of alertness. Controlling for group size and neighbour density, gulls interrupted sleep more often to scan their surroundings, and were therefore more vigilant, when their neighbours were alert rather than sleeping or preening. The results provide evidence for copying of vigilance within groups of birds, suggesting a complex flow of information about predation risk in groups.
群体中的个体通常被认为会相互独立地扫视周围环境以寻找威胁。然而，模型表明觅食者应该监测邻居的警惕程度，以防止欺骗行为，并收集有关初期捕食风险的信息。关于监测警惕性的证据很少。在这里，我研究了处于不同警觉状态的邻居环绕下的睡眠海鸥（鸥属）警惕水平的变化。在控制了群体规模和邻居密度后，当邻居处于警觉状态而非睡眠或梳理羽毛时，海鸥会更频繁地中断睡眠来扫视周围环境，因此也更加警惕。这些结果为鸟类群体内警惕性的模仿提供了证据，表明群体中存在关于捕食风险的复杂信息流动。
