Tourists approaching wild animals can potentially cause disturbance as a result of the perceived predation risk. Risk effects arise when prey alter their behaviour in response to predators. This response may carry costs through its impact on fitness-related activities such as foraging. We recorded behavioural responses of whale sharks Rhincodon typus to experimental vessel and swimmer approaches. We simulated the disturbance caused by ecotourism in the foraging site of this planktivorous fish in Bahia de Los Angeles, Gulf of Baja California, Mexico. Stress-related behaviours (vigilance, change of direction, diving and acceleration) were more common directly after both types of disturbance than before, in particular after approach by a swimmer. Individuals were more likely to be vigilant when they were new to the bay, but we did not find evidence of within-season behavioural habituation. Sharks were 24% more likely to forage before human stimuli than after. Our study highlights negative effects of vessel and swimmer approaches on whale shark behaviour, with a short-term increase in stress-related behaviours potentially carrying energetic costs, combined with a decrease in food intake following the disturbance. Our results indicate concerns about the impact of ecotourism on large fish species. An important next step would be to determine whether these short-term behavioural responses to the perception of predation risk negatively affect fitness. Among other guidelines, we recommend preventing swimmers from approaching if whale sharks stop feeding when a vessel approaches.

中文翻译：

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生态旅游对鲸鲨行为的影响：一种实验方法

由于感知到的捕食风险，接近野生动物的游客可能会造成干扰。当猎物改变其行为以应对捕食者时，风险效应就会出现。这种反应可能会通过影响与健身相关的活动（例如觅食）来产生成本。我们记录了鲸鲨的行为反应犀牛到实验船和游泳者的方法。我们在墨西哥下加利福尼亚湾的洛杉矶巴伊亚湾的这种浮游鱼类的觅食地模拟了生态旅游造成的干扰。在两种类型的干扰之后，与压力相关的行为（警惕、改变方向、潜水和加速）比之前更常见，特别是在游泳者接近之后。当人们刚到海湾时，他们更有可能保持警惕，但我们没有发现季节内行为习惯的证据。鲨鱼在人类刺激之前觅食的可能性比之后高出 24%。我们的研究强调了船只和游泳者方法对鲸鲨行为的负面影响，压力相关行为的短期增加可能会带来能量成本，加上干扰后食物摄入量的减少。我们的结果表明人们担心生态旅游对大型鱼类的影响。下一步重要的是确定这些对捕食风险感知的短期行为反应是否会对健康产生负面影响。在其他指导方针中，我们建议在船只靠近时鲸鲨停止进食时阻止游泳者靠近。