Translocations, defined herein as the human‐assisted movement of individuals from a source population to other waters within their historical range, are prevalent in recovery plans for endangered fishes. Many translocations fail to establish new populations, however, and outcomes are often poorly documented. Endangered Humpback Chub Gila cypha persist as a self‐sustaining population in Grand Canyon, Arizona, despite threats from introduced nonnative competitors and predators and modified flow, thermal, and sediment regimes due to river regulation. In the decades following the completion of Glen Canyon Dam, the Grand Canyon population has been primarily sustained through reproduction in a single Colorado River tributary, the Little Colorado River (LCR). To establish population redundancy and aid in recovery, we annually translocated between 243 and 509 juvenile Humpback Chub from the LCR to Havasu Creek, a smaller Colorado River tributary in Grand Canyon National Park. Juvenile Humpback Chub were collected from the wild and reared in a hatchery for 8–12 months prior to the translocations. Through biannual mark–recapture sampling in Havasu Creek, we estimated annual abundance for all of the translocated cohorts and found that apparent survival and growth rates met or exceeded the demographic rates that are published for the LCR. We observed reproductively mature adults each year in May, beginning in 2012, and untagged juvenile Humpback Chub beginning in the following year and every year thereafter, with results that indicated successful reproduction. Beginning in 2016, we noted recruitment to maturity of fish that were produced in situ and the population's abundance increased through 2018, indicating potential for the establishment of a self‐sustaining population. As an example of the successful translocation of an endangered species that demonstrates the potential importance of tributaries in the recovery of large‐river fishes, our study may help to inform future recovery planning.

中文翻译：

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通过易位到亚利桑那州大峡谷的科罗拉多河支流，建立濒临灭绝的座头鲸繁殖种群

易位，在此定义为人类从原始种群到其历史范围内其他水域的人工协助移动，在濒危鱼类的恢复计划中很普遍。许多易位未能建立新的种群，但是结果往往文献记载不充分。濒临灭绝的座头鲸丘吉拉尽管受到外来竞争者和掠食者的威胁以及由于河流调节而改变的流量，热量和泥沙状况的威胁，但在亚利桑那州大峡谷作为一个自给自足的人口仍然存在。在格伦峡谷大坝建成后的几十年中，大峡谷的人口主要通过在科罗拉多河的一个支流小科罗拉多河（LCR）中繁殖而得以维持。为了建立人口冗余并帮助灾后恢复，我们每年将243至509头驼背幼崽从LCR转移到大峡谷国家公园中较小的科罗拉多河支流Havasu Creek。从野外收集幼体座头鲸，然后在易位之前在孵化场中饲养8-12个月。通过在哈瓦苏河（Havasu Creek）中每两年进行一次标记回收，我们估算了所有易位人群的年均丰度，发现表观生存率和增长率达到或超过了LCR公布的人口率。我们从2012年开始的每年5月观察到具有生殖能力的成年成年人，从次年开始及其后的每年开始观察未加标签的少年座头鲸，结果表明繁殖成功。从2016年开始，我们注意到就地捕捞到成熟鱼类的招募工作，到2018年，鱼类种群的数量增加了，这表明建立自给自足种群的潜力。作为成功转移濒危物种的一个例子，它表明了支流在大河鱼类恢复中的潜在重要性，我们的研究可能有助于为未来的恢复计划提供依据。