Annual population growth in songbirds can be particularly sensitive to post-fledging survival, but research and management are frequently biased toward the nesting stage. Post-fledging information is particularly scarce for species breeding in desert bird communities, many of which have collapsed in recent decades. During 2017–2019 at Sevilleta National Wildlife Refuge, New Mexico, USA, we used radio telemetry to monitor survival, movements, and habitat associations of 90 fledgling Gray Vireos (Vireo vicinior), a desert-dwelling species of conservation concern. We used logistic exposure models to investigate the relationship between fledgling survival and habitat features at two spatial scales. Overall, we estimated that 51 ± 8% of fledglings survived the monitoring period. All mortalities occurred during the first 12 days post-fledging and were attributed to predation and environmental exposure. In daily survival models focused on predation mortalities, age was the strongest predictor of survival. Daily survival rate was not related to any habitat variables we measured. Percent tree cover used by birds during the first 12 days post-fledging was similar to that of nesting sites and greater than that of random locations. Similarly, fledglings occupied individual trees and shrubs with lateral vegetation cover similar to that of nest locations. Minimum daily distance traveled, distance from nests, and variance associated with these measures, all increased with age. Except for the use of a larger area, habitats used by Gray Vireos during the post-fledging period were similar to those used for nesting in our study population, indicating that maintenance of large patches of moderately dense juniper is desirable for this species. More study is needed from populations in less pristine and more heterogeneous landscapes. More broadly, given the importance of first-year survival in demographic models and the declines of dryland birds, information is needed on the post-fledging period of many desert songbirds.

中文翻译：

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新墨西哥州 Grey Vireos 羽化后的生存、运动和栖息地关联

鸣禽的年种群增长对羽化后的生存特别敏感，但研究和管理经常偏向筑巢阶段。对于沙漠鸟类群落的物种繁殖来说，羽翼后的信息尤其稀缺，其中许多已经在近几十年里崩溃了。2017-2019 年期间，我们在美国新墨西哥州的塞维利亚国家野生动物保护区使用无线电遥测技术监测了 90 只初出茅庐的 Grey Vireos (Vireo vicinior) 的生存、活动和栖息地关联，这是一种受到保护的沙漠栖息物种。我们使用逻辑暴露模型来研究两个空间尺度上的新生生存与栖息地特征之间的关系。总体而言，我们估计有 51 ± 8% 的雏鸟在监测期内幸存下来。所有死亡都发生在羽化后的前 12 天，归因于捕食和环境暴露。在以捕食死亡率为重点的日常生存模型中，年龄是生存的最强预测因子。每日存活率与我们测量的任何栖息地变量无关。鸟类在羽化后的前 12 天内使用的树木覆盖百分比与筑巢地点相似，并且高于随机位置。同样，雏鸟占据了与巢穴位置相似的侧向植被覆盖的个别树木和灌木。每日最少行进距离、与巢穴的距离以及与这些措施相关的差异，都随着年龄的增长而增加。除了使用面积更大，Gray Vireos 在羽化后使用的栖息地与我们研究种群中用于筑巢的栖息地相似，这表明该物种需要维持大片中等密度的杜松。需要对不太原始和更多异质景观的人群进行更多研究。更广泛地说，鉴于人口模型中第一年生存的重要性和旱地鸟类的减少，需要有关许多沙漠鸣禽后羽期的信息。