Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada.
Laterality. 2011 Jul;16(4):471-8. doi: 10.1080/1357650X.2010.485202.
Using field observations of ~15 wild adult black bear (Ursus americanus kermodei) foraging on a salmon stream during two autumns on the central coast of British Columbia, we tested for laterality of forelimb use during lunging and during handling of salmon. Of 288 lunging events observed overall, 53% were non biased, 26% were right-limb biased, and 21% left-limb biased (p = .53 between left and right bias). Among six bears in which we could ascertain individual identity (182 lunging events), there was heterogeneity among individuals (p <.05) of which two were significantly right biased and one significantly left biased (p<.005). Of 186 carcass-handling (pick-up) events, 68% were right-pawed (p <.005) and there was no heterogeneity among five individually identifiable bears (p = .19). There was no forelimb laterality in adjustment of the prey in the mouth or in securing the prey to the substrate. This is the first report of task-specific behavioural lateralisation of a wild carnivore and is suggestive of a right bias (left-hemisphere dominance) in object manipulation.
在不列颠哥伦比亚省中部海岸的两个秋季,通过对 15 只成年黑熊(Ursus americanus kermodei)在鲑鱼溪流觅食的实地观察,我们测试了在猛扑和处理鲑鱼时前肢使用的偏向性。在总共观察到的 288 次猛扑事件中,53%是非偏向性的,26%是右侧偏向性的,21%是左侧偏向性的(左侧和右侧偏向性之间的 p =.53)。在我们能够确定个体身份的六只熊中(182 次猛扑事件),个体之间存在异质性(p <.05),其中两只明显偏向右侧,一只明显偏向左侧(p<.005)。在 186 次尸体处理(捡起)事件中,68%是右爪(p <.005),五个可识别个体的熊之间没有异质性(p =.19)。在调整口中的猎物或将猎物固定在基质上时,前肢没有偏向性。这是首例关于野生食肉动物特定任务行为偏向性的报告,表明在物体操纵中存在右侧偏向性(左侧半球优势)。