Wright Brianna M, Ford John K B, Ellis Graeme M, Deecke Volker B, Shapiro Ari Daniel, Battaile Brian C, Trites Andrew W
Marine Mammal Research Unit, Institute for the Oceans and Fisheries, University of British Columbia, AERL Building, Room 247 - 2202 Main Mall, Vancouver, BC V6T 1Z4 Canada.
Department of Zoology, University of British Columbia, #4200 - 6270 University Blvd., Vancouver, BC V6T 1Z4 Canada.
Mov Ecol. 2017 Feb 20;5:3. doi: 10.1186/s40462-017-0094-0. eCollection 2017.
We sought to quantitatively describe the fine-scale foraging behavior of northern resident killer whales (), a population of fish-eating killer whales that feeds almost exclusively on Pacific salmon ( spp.). To reconstruct the underwater movements of these specialist predators, we deployed 34 biologging Dtags on 32 individuals and collected high-resolution, three-dimensional accelerometry and acoustic data. We used the resulting dive paths to compare killer whale foraging behavior to the distributions of different salmonid prey species. Understanding the foraging movements of these threatened predators is important from a conservation standpoint, since prey availability has been identified as a limiting factor in their population dynamics and recovery.
Three-dimensional dive tracks indicated that foraging ( = 701) and non-foraging dives ( = 10,618) were kinematically distinct (Wilks' lambda: = 0.321, < 0.001). While foraging, killer whales dove deeper, remained submerged longer, swam faster, increased their dive path tortuosity, and rolled their bodies to a greater extent than during other activities. Maximum foraging dive depths reflected the deeper vertical distribution of Chinook (compared to other salmonids) and the tendency of Pacific salmon to evade predators by diving steeply. Kinematic characteristics of prey pursuit by resident killer whales also revealed several other escape strategies employed by salmon attempting to avoid predation, including increased swimming speeds and evasive maneuvering.
High-resolution dive tracks reconstructed using data collected by multi-sensor accelerometer tags found that movements by resident killer whales relate significantly to the vertical distributions and escape responses of their primary prey, Pacific salmon.
我们试图定量描述北居留虎鲸（Orcinus orca）的精细觅食行为，这是一群主要以鱼类为食的虎鲸，几乎完全以太平洋鲑鱼（Oncorhynchus spp.）为食。为了重建这些专业捕食者的水下运动，我们在32头个体上部署了34个生物记录D标签，并收集了高分辨率的三维加速度计和声学数据。我们利用由此得到的潜水路径，将虎鲸的觅食行为与不同鲑科猎物物种的分布进行比较。从保护的角度来看，了解这些受威胁捕食者的觅食运动很重要，因为猎物的可获得性已被确定为其种群动态和恢复的限制因素。
三维潜水轨迹表明，觅食潜水（n = 701）和非觅食潜水（n = 10,618）在运动学上是不同的（威尔克斯λ：λ = 0.321，P < 0.001）。在觅食时，虎鲸潜得更深，在水下停留的时间更长，游得更快，潜水路径的曲折度增加，并且身体滚动的程度比其他活动时更大。最大觅食潜水深度反映了奇努克鲑（与其他鲑科鱼类相比）更深的垂直分布，以及太平洋鲑鱼通过急剧下潜躲避捕食者的趋势。居留虎鲸追捕猎物的运动学特征还揭示了鲑鱼试图避免被捕食所采用的其他几种逃避策略，包括提高游泳速度和进行规避机动。
利用多传感器加速度计标签收集的数据重建的高分辨率潜水轨迹发现，居留虎鲸的运动与它们的主要猎物太平洋鲑鱼的垂直分布和逃避反应密切相关。
