Fish crows (Corvus ossifragus) can be important seabird egg predators. In southwestern Florida, USA, crows were previously documented as causing the abandonment of black skimmer (Rynchops niger) colonies. While lethal crow control might be the most effective strategy, there are ethical and practical concerns about corvid control in an urban setting. Illness‐induced aversion to egg eating (conditioned taste aversion) is an alternative that has the potential for decreasing corvid depredation of seabird eggs. In addition, conditioned stimulus aversion using nonlethal shocks on corvids taking electrified eggs might also be effective. We tested conditioned taste aversion using quail eggs injected with carbachol (emetic eggs) at 3 black skimmer colonies during the 2016 breeding season. We tested conditioned stimulus aversion using electrified quail eggs at the same colonies during the 2017 breeding season. We compared the number of skimmer eggs in a colony depredated by crows before and after a 10‐day treatment. Both methods of treatment significantly decreased the number of skimmer eggs depredated by crows and were relatively inexpensive to conduct. In urban settings, electrified eggs are the safer option as many of the crows took the emetic eggs, but did not consume them while near the colony, potentially exposing non‐target species to a toxicant. © 2020 The Wildlife Society.

中文翻译：

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两种抑制海鸟卵淘汰鱼乌鸦方法的比较。

鱼乌鸦（乌鸦ossifragus）可能是重要的海鸟蛋捕食者。在美国佛罗里达州西南部，以前有乌鸦被记录为导致抛弃了黑色撇渣器（Rynchops niger）） 群落。尽管致命的乌鸦控制可能是最有效的策略，但在城市环境中，对狂犬病的控制仍存在道德和实践上的顾虑。疾病引起的对食蛋的厌恶（条件性味觉厌恶）是一种可能减少海鸟卵弯弯剥落的替代方法。此外，对带电蛋的幼崽使用非致命性电击进行条件刺激规避也可能是有效的。我们在2016繁殖季节期间使用3个黑色撇渣器菌落注射了卡巴胆碱的鹌鹑蛋（催吐卵）测试了条件化口味回避。我们在2017繁殖季节的相同殖民地使用带电鹌鹑蛋测试了条件刺激刺激。我们比较了在10天的治疗前后乌鸦淘汰的菌落中分离器卵的数量。两种处理方法均显着减少了乌鸦不赞成使用的撇蛋的数量，并且实施起来相对便宜。在城市环境中，带电鸡蛋是更安全的选择，因为许多乌鸦都吃了催吐卵，但在殖民地附近却没有食用它们，这有可能使非目标物种接触到有毒物质。©2020野生动物协会。