Remote islands as natural laboratories: human-food association increases attraction to humans and novelty exploration in a seabird.

Increased attraction to humans and their objects often arises after repeated and positive human-wildlife encounters (e.g., food provided in tourist settings). Causes of this ‘over-attraction’, which may result from a learned association between humans and food, are still poorly studied in wild animals. Understanding the influence of humans on animals’ responses is yet crucial to prevent negative effects (e.g., aggression). We presented three novel objects to two groups of free-ranging brown skuas (Catharacta antarctica ssp. lonnbergi) in the remote sub-Antarctic, where their habitats show no or minimal human disturbance. Skuas in one group (Verte) had previously participated in repeated food-rewarded behavioural and cognitive tasks with a human experimenter; skuas in the other group (Ratmanoff) had never done so. Objects consisted of (i) one natural-food-resembling object (plastic fish), (ii) one anthropogenic food object (real cake slice), and (iii) one anthropogenic non-food object (yellow glove). Verte group skuas approached the human experimenter and pecked significantly more and sooner at novel objects. Human-food association may have thus resulted in increased attraction to humans and novelty exploration in previously naive brown skuas, making this species a useful model for investigating the consequences of experience with humans on wildlife behaviour.

人类与野生动物间反复且积极的互动（例如旅游场景中的食物投喂）后，野生动物往往会提升对人类及其物品的吸引力。这种‘过度吸引力（over-attraction）’可能源于人类与食物之间的习得性关联，但其成因在野生动物中仍鲜有研究。明晰人类对动物行为反应的影响，对规避攻击等负面后果至关重要。本研究在人类干扰极少甚至完全无干扰的偏远亚南极区域，向两组自由活动的棕贼鸥（Catharacta antarctica ssp. lonnbergi）展示了三种全新物品。其中一组（Verte组）的棕贼鸥此前曾与人类实验员参与过多次以食物为奖励的行为学与认知任务；另一组（Ratmanoff组）的个体则从未参与过此类实验。本次实验所用物品分别为：(i) 模仿天然食物的塑料鱼模型，(ii) 人工食物类物品（真实蛋糕块），以及(iii) 人工非食物类物品（黄色手套）。实验结果显示，Verte组的棕贼鸥会主动靠近人类实验员，且对全新物品的啄击频次显著更高、首次啄击的潜伏期更短。由此可见，人类与食物的习得性关联，或许会让此前无人类互动经验的棕贼鸥增强对人类的亲近性与对新奇事物的探索欲，该物种因此可作为研究人类互动经历对野生动物行为影响的理想模型。