Sutton Grace J, Hoskins Andrew J, Berlincourt Maud, Arnould John P Y
Deakin University, School of Life and Environmental Sciences (Burwood Campus), Victoria, Australia.
CSIRO Land and Water, Canberra, Australian Capital Territory, Australia.
PLoS One. 2017 Aug 23;12(8):e0182734. doi: 10.1371/journal.pone.0182734. eCollection 2017.
Recent studies have documented that little penguins (Eudyptula minor) associate at sea, displaying synchronised diving behaviour throughout a foraging trip. However, previous observations were limited to a single foraging trip where only a small number of individuals were simultaneously tracked. Consequently, it is not known whether coordinated behaviour is consistent over time, or what factors influence it. In the present study, breeding adults were concurrently instrumented with GPS and dive behaviour data loggers for at least 2 consecutive foraging trips during guard and post-guard stage at two breeding colonies (London Bridge and Gabo Island, south-eastern Australia) of contrasting population size (approximately 100 and 30,000-40,000, respectively). At both colonies, individuals were sampled in areas of comparable nesting density and spatial area. At London Bridge, where individuals use a short (23 m) common pathway from their nests to the shoreline, > 90% (n = 42) of birds displayed foraging associations and 53-60% (n = 20) maintained temporally consistent associations with the same conspecifics. Neither intrinsic (sex, size or body condition) nor extrinsic (nest proximity) factors were found to influence foraging associations. However, individuals that departed from the colony at a similar time were more likely to associate during a foraging trip. At Gabo Island, where individuals use a longer (116 m) pathway with numerous tributaries to reach the shoreline, few individuals (< 31%; n = 13) from neighbouring nests associated at sea and only 1% (n = 1) maintained associations over subsequent trips. However, data from animal-borne video cameras indicated individuals at this colony displayed foraging associations of similar group size to those at London Bridge. This study reveals that group foraging behaviour occurs at multiple colonies and the pathways these individuals traverse with conspecifics may facilitate opportunistic group formation and resulting in foraging associations irrespective of nesting proximity and other factors.
最近的研究记录表明，小企鹅（小企鹅属）在海上会聚集在一起，在整个觅食行程中表现出同步潜水行为。然而，先前的观察仅限于单次觅食行程，当时仅同时追踪了少数个体。因此，尚不清楚协调行为是否随时间保持一致，或者哪些因素会对其产生影响。在本研究中，在澳大利亚东南部两个种群规模不同（分别约为100只和30000 - 40000只）的繁殖群体（伦敦桥和加波岛）的警戒期和警戒后期，对繁殖成年企鹅同时配备了GPS和潜水行为数据记录器，进行至少连续2次觅食行程的监测。在两个群体中，均在筑巢密度和空间区域相当的区域对个体进行采样。在伦敦桥，个体从巢穴到海岸线使用一条较短（23米）的公共路径，超过90%（n = 42）的鸟类表现出觅食关联，53 - 60%（n = 20）与相同的同种个体保持时间上一致的关联。未发现内在因素（性别、大小或身体状况）和外在因素（巢穴距离）对觅食关联有影响。然而，同时离开群体的个体在觅食行程中更有可能聚集在一起。在加波岛，个体使用一条较长（116米）且有许多支流的路径到达海岸线，来自相邻巢穴的个体很少（< 31%；n = 13）在海上聚集，只有1%（n = 1）在后续行程中保持关联。然而，动物携带的摄像机数据表明，该群体的个体表现出的觅食聚集群体规模与伦敦桥的类似。这项研究表明，群体觅食行为在多个群体中都会出现，这些个体与同种个体一起走过的路径可能有助于机会性群体的形成，并导致觅食关联，而与筑巢距离和其他因素无关。
