Shoji Akiko, Aris-Brosou Stéphane, Fayet Annette, Padget Oliver, Perrins Christopher, Guilford Tim
Oxford University, Department of Zoology, South Parks Road, Oxford OX1 3PS, UK
University of Ottawa, Department of Mathematics, Ottawa, Ontario, Canada K1N 6N5.
J Exp Biol. 2015 Jul;218(Pt 13):2116-23. doi: 10.1242/jeb.120626. Epub 2015 May 11.
The optimal allocation of time and energy between one's own survival and offspring survival is critical for iteroparous animals, but creates a conflict between what maximises the parent's fitness and what maximises fitness of the offspring. For central-place foragers, provisioning strategies may reflect this allocation, while the distance between central-places and foraging areas may influence the decision. Nevertheless, few studies have explored the link between life history and foraging in the context of resource allocation. Studying foraging behaviour alongside food load rates to chicks provides a useful system for understanding the foraging decisions made during parent-offspring conflict. Using simultaneously deployed GPS and time-depth recorders, we examined the provisioning strategies in free-living Manx shearwaters Puffinus puffinus, which were caring for young. Our results showed a bimodal pattern, where birds alternate short and long trips. Short trips were associated with higher feeding frequency and larger meals than long trips, suggesting that long trips were performed for self-feeding. Furthermore, most foraging was carried out within 100 km of sea fronts. A simple model based on patch quality and travel time shows that for Manx shearwaters combining chick feeding and self-maintenance, bimodal foraging trip durations optimise feeding rates.
对于多次繁殖的动物来说，在自身生存和后代生存之间合理分配时间和精力至关重要，但这在最大化亲代适合度和最大化子代适合度之间产生了冲突。对于中心地觅食者而言，育雏策略可能反映了这种分配情况，而中心地与觅食区域之间的距离可能会影响这一决策。然而，很少有研究在资源分配的背景下探讨生活史与觅食之间的联系。结合雏鸟食物负载率来研究觅食行为，为理解亲子冲突期间的觅食决策提供了一个有用的系统。我们同时使用全球定位系统（GPS）和时间深度记录仪，研究了自由生活的正在育雏的马恩岛剪水鹱（Puffinus puffinus）的育雏策略。我们的研究结果显示出一种双峰模式，即鸟类在短途和长途旅行之间交替。与长途旅行相比，短途旅行的喂食频率更高，每餐食量更大，这表明长途旅行是为了自我觅食。此外，大多数觅食活动在距海前线100公里范围内进行。一个基于斑块质量和旅行时间的简单模型表明，对于兼顾雏鸟喂食和自我维持的马恩岛剪水鹱来说，双峰觅食行程持续时间能优化喂食率。
