Abstract Species extinctions are becoming a global crisis, affecting biodiversity and ecosystem services, with island populations being particularly vulnerable. In response, conservation managers are increasingly turning to ex situ conservation breeding programs to establish assurance populations and provide a source for release and re-establishment of wild populations. The 'Alalā (Hawaiian crow, Corvus hawaiiensis) is a critically endangered and territorial island corvid that became extinct in the wild in 2002, following a severe and prolonged population decline during the late 20th century. Surviving individuals of the species were brought into captivity to establish an assurance population to serve as a source for reintroduction, which commenced in 2016. We analyzed the extent to which a range of captive housing conditions impact 'Alalā reproductive success, using 19 years of breeding program data. We found that reproductive success was most strongly affected by the distance between aviaries and their closest neighbors and whether breeding pairs had visual access to other adult conspecifics. Pairs located in aviaries that were more spatially isolated and without visual access to conspecifics were more likely to produce fertile eggs than pairs housed in aviaries that were closer to others or those with visual access to other birds. Our results have direct management implications relevant to the design of conservation breeding centers geared towards the recovery of endangered, territorial bird species. Moreover, since suboptimal housing conditions can increase stress levels in captive birds, our findings are also relevant to improving animal welfare for 'Alalā and other species in conservation breeding programs.

中文翻译：

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鸟舍间距离和视觉可达性影响领土濒危鸟类的保护育种结果

摘要 物种灭绝正在成为全球危机，影响生物多样性和生态系统服务，岛屿人口尤其脆弱。作为回应，保护管理者越来越多地转向异地保护育种计划，以建立保证种群并为野生种群的释放和重建提供来源。'Alalā（夏威夷乌鸦，Corvus hawaiiensis）是一种极度濒临灭绝的领土岛鸦科动物，在 20 世纪后期经历了严重而长期的人口下降之后，于 2002 年在野外灭绝。该物种的幸存个体被圈养，以建立保证种群作为重新引入的来源，该工作于 2016 年开始。我们分析了一系列圈养住房条件影响的程度。Alalā 繁殖成功，使用 19 年的育种计划数据。我们发现繁殖成功受鸟舍与其最近邻居之间的距离以及繁殖对是否可以看到其他成年同种动物的影响最大。位于空间上更隔离且无法看到同种鸟的鸟舍中的配对比饲养在与其他鸟类更近的鸟舍中或与其他鸟类有视觉接触的鸟舍中的配对更有可能产生受精卵。我们的研究结果对旨在恢复濒临灭绝的领土鸟类物种的保护繁殖中心的设计具有直接的管理意义。此外，由于次优的饲养条件会增加圈养鸟类的压力水平，我们的研究结果也与改善动物福利有关