Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2.
World Whaling History, Redding, CA, USA.
Biol Lett. 2021 Mar;17(3):20210030. doi: 10.1098/rsbl.2021.0030. Epub 2021 Mar 17.
Animals can mitigate human threats, but how do they do this, and how fast can they adapt? Hunting sperm whales was a major nineteenth century industry. Analysis of data from digitized logbooks of American whalers in the North Pacific found that the rate at which whalers succeeded in harpooning ('striking') sighted whales fell by about 58% over the first few years of exploitation in a region. This decline cannot be explained by the earliest whalers being more competent, as their strike rates outside the North Pacific, where whaling had a longer history, were not elevated. The initial killing of particularly vulnerable individuals would not have produced the observed rapid decline in strike rate. It appears that whales swiftly learned effective defensive behaviour. Sperm whales live in kin-based social units. Our models show that social learning, in which naive social units, when confronted by whalers, learned defensive measures from grouped social units with experience, could lead to the documented rapid decline in strike rate. This rapid, large-scale adoption of new behaviour enlarges our concept of the spatio-temporal dynamics of non-human culture.
动物可以减轻人类的威胁，但它们是如何做到的，又能多快适应呢？十九世纪，猎捕抹香鲸曾是一项主要产业。对北太平洋地区美国捕鲸者数字化航海日志数据的分析发现，在一个区域的最初几年的开发中，捕鲸者成功用鱼叉刺中（“击中”）目击鲸鱼的成功率下降了约 58%。这一下降不能用早期捕鲸者更有能力来解释，因为他们在北太平洋以外地区（那里的捕鲸历史更长）的刺中率并没有提高。最初对特别脆弱的个体的捕杀不会导致所观察到的刺中率的快速下降。看来，鲸鱼很快就学会了有效的防御行为。抹香鲸生活在以亲缘关系为基础的社会群体中。我们的模型表明，社会学习——当面临捕鲸者时，没有经验的社会群体从有经验的群体中学习防御措施——可能导致记录到的刺中率的快速下降。这种快速、大规模采用新行为扩大了我们对非人类文化的时空动态的概念。
