Captive-reared European hamsters follow an offensive strategy during risk-assessment

Understanding whether captive-reared animals destined to reintroduction are still able to discriminate predators has important implications for conservation biology. The endangered European hamster benefits from conservation programs throughout Europe, in which several thousand individuals are released into the wild every year. Despite this, the anti-predator strategy of hamsters and their ability to maintain predator discrimination in captivity remain to be investigated. Here, we explore the predator discrimination behaviour of captive-reared European hamsters and their response to different predation cues. When first exposed to the urine of cats and goats in a Y-maze test, hamsters spent more time close to the cat scent rather than to the goat scent. In a second experiment, during which hamsters were exposed to a non-mobile European ferret (inside a cage), hamsters significantly increased the time spent close to the ferret’s cage and displayed aggressive behaviour towards the ferret. Furthermore, they did not take refuge inside an anti-predation tube (APT), a device designed to upgrade wildlife underpasses and reconnect wild hamster populations. Finally, when exposed to a mobile ferret (but without physical contact), hamsters displayed mobbing and aggressive behaviours towards the ferret, before taking refuge inside the APT. Taken together, our results show that captive-reared hamsters are still able to detect and react to predation cues, but that they initially adopt an offensive strategy (grunting, spitting, mobbing) during the risk-assessment phase. After risk assessment, however, hamsters used the APT as a refuge. Our study provides important insights into the anti-predator behaviour of hamsters. Testing the efficacy of the APT, a device that will allow upgrading wildlife underpasses for the hamster and other rodents, is also of great importance and is instrumental in conservation efforts for these species.探明用于野化放归的人工繁育动物是否仍具备天敌识别能力，对保护生物学领域具有重要价值。作为濒危物种，欧洲仓鼠（European hamster）受益于全欧范围内的保护计划，每年均有数千只个体被放归野外。尽管如此，该物种的反捕食策略及其在人工圈养条件下维持天敌识别能力的机制仍有待探究。 本研究针对人工繁育的欧洲仓鼠，探究其天敌识别行为及对不同捕食线索的响应模式。在Y型迷宫（Y-maze）试验中，当首次接触猫与山羊的尿液气味时，仓鼠会在猫的气味区域停留更长时间，而非山羊气味区域。在第二项实验中，当仓鼠接触笼养不动的欧洲雪貂时，其在雪貂笼附近停留的时间显著增加，并对雪貂表现出攻击行为。此外，仓鼠并未选择进入反捕食通道（anti-predation tube, APT）——该装置旨在升级野生动物地下通道，以促进野生仓鼠种群间的连通。最后，当接触可移动的雪貂（无物理接触）时，仓鼠会先对雪貂表现出围攻与攻击行为，随后才进入APT避难。 综合来看，本研究结果表明，人工繁育的欧洲仓鼠仍可感知并响应捕食线索，但在风险评估阶段初期会采取主动进攻策略（包括低吼、喷吐、围攻行为）。完成风险评估后，仓鼠则会将APT作为避难场所。本研究为仓鼠的反捕食行为研究提供了重要参考。同时，针对APT（用于升级仓鼠及其他啮齿类动物的野生动物地下通道）的效能评估，也对该类物种的保护工作具有重要的推动作用。