Wildfowl & Wetlands Trust, Slimbridge Wetland Centre, Slimbridge, Gloucestershire, United Kingdom.
Centre for Research in Animal Behaviour, Psychology, Washington Singer, University of Exeter, Exeter, Devon, United Kingdom.
PLoS One. 2022 Jul 8;17(7):e0271257. doi: 10.1371/journal.pone.0271257. eCollection 2022.
Individual animals engage in many behaviours which are mutually exclusive, and so where individuals increase the duration of time spent on one type of behavioural activity, this must be offset by a corresponding decrease in at least one other type of behaviour. To understand the variation observed in animal behaviour, researchers need to know how individuals trade-off these mutually-exclusive behaviours within their time-activity budget. In this study, we used remotely collected behavioural observations made from a live-streaming webcam to investigate trade-offs in the behaviour of two bird species, the mute swan (Cygnus olor) and whooper swan (Cygnus cygnus). For both species, we tested for correlations in the duration of time spent on key mutually exclusive behaviours: aggression, foraging, maintenance, and resting. We detected a negative association between aggression and resting behaviours in both species, indicating that increased aggression is achieved at the expense of resting behaviour. In contrast, there was no apparent trade-off between aggression and foraging, aggression and maintenance, or maintenance and resting. Foraging and resting behaviours were negatively correlated in both species, highlighting a trade-off between these distinct modes of behaviour. A trade-off between foraging and maintenance behaviours was detected for the sedentary mute swans, but not the migratory whooper swans. Our findings show how birds can trade-off their time investments in mutually exclusive behaviours within their time-activity budgets. Moreover, our study demonstrates how remotely-collected data can be used to investigate fundamental questions in behavioural research.
个体动物会进行许多相互排斥的行为，因此当个体增加某种行为活动的持续时间时，这必须通过相应减少至少另一种行为来抵消。为了理解动物行为中观察到的变化，研究人员需要了解个体如何在其时间活动预算内权衡这些相互排斥的行为。在这项研究中，我们使用从实时流媒体网络摄像头远程收集的行为观察结果，调查了两种鸟类（默西鹅（Cygnus olor）和大天鹅（Cygnus cygnus））行为的权衡。对于这两个物种，我们测试了关键的相互排斥行为（攻击、觅食、维护和休息）的持续时间之间的相关性。我们在两个物种中都检测到攻击和休息行为之间存在负相关，这表明增加攻击是以牺牲休息行为为代价的。相比之下，攻击和觅食、攻击和维护或维护和休息之间似乎没有明显的权衡。在两个物种中，觅食和休息行为呈负相关，突出了这两种不同行为模式之间的权衡。对于久坐不动的默西鹅，觅食和维护行为之间存在权衡，但对于迁徙的大天鹅则不存在。我们的研究结果表明，鸟类如何在其时间活动预算内权衡相互排斥的行为中的时间投入。此外，我们的研究表明，如何使用远程收集的数据来研究行为研究中的基本问题。
