Post-fledging survival of northern goshawks: the importance of prey abundance, weather, and dispersal.
Post-fledging survival of northern goshawks: the importance of prey abundance, weather, and dispersal.
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北方苍鹰羽翼未丰后的生存：猎物丰富度、天气和扩散的重要性。
DOI：
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发表时间：
2006
影响因子：
5
通讯作者：
Richard T. Reynolds
中科院分区：
文献类型：
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作者：
J. Wiens;B. Noon;Richard T. Reynolds
有效的野生动物保护战略需要了解波动的环境条件如何影响敏感的生命阶段。作为一项长期研究的一部分，我们研究了89个放射性标记的少年北方苍鹰（鹰generus）从48个巢在美国亚利桑那州北方，在1998-2001年期间，羽翼丰满和独立后的生存。信息理论的方法被用来检查内和第二年的生存变化相对于环境（猎物丰度，天气），领土（孵化日期，育雏大小），和个人（性别，体重）的变化来源。研究结果支持年龄和集群特定的生存差异，最好的解释发生在不同阶段的青少年发展，主要鸟类和哺乳动物猎物物种的密度每年的变化，和性别相关的差异体重的行为。初出茅庐和独立之间的生存率随年龄线性增加，并在放射性标记的青少年的年度队列中变化，从0.81（95% CI = 0.60-0.93）至1.00（95% CI = 0.95-1.00）与猎物密度的年度差异有关;猎物密度对存活率的加性效应的斜率系数为1.12（95% CI = 0.06-2.19）。存活率下降到0.71（95%CI = 0.60-0.93）后不久，少年开始分散（8-12周后羽翼），并搬到更开放的栖息地在低海拔。生存率与天气或领土水平参数没有密切关系。环境，领土，和个人为基础的生存模型的预测比较表明，食物的可用性是限制少年生存的主要因素。这一发现表明，森林管理处方，旨在支持丰富的猎物种群，同时提供森林结构条件，让苍鹰进入他们的猎物在繁殖区应有利于少年生存。
Effective wildlife conservation strategies require an understanding of how fluctuating environmental conditions affect sensitive life stages. As part of a long-term study, we examined post-fledging and post-independence survival of 89 radio-marked juvenile Northern Goshawks (Accipiter gentilis) produced from 48 nests in northern Arizona, USA, during 1998-2001. Information-theoretic methods were used to examine within- and among-year variation in survival relative to environmental (prey abundance, weather), territory (hatching date, brood size), and individual (gender, body mass) sources of variation. The results support age- and cohort-specific differences in survival that were best explained by behaviors occurring at distinct stages of juvenile development, annual changes in the density of primary bird and mammal prey species, and gender-related differences in body mass. Survival between fledging and independence increased linearly with age and varied among annual cohorts of radio-marked juveniles from 0.81 (95% CI = 0.60-0.93) to 1.00 (95% CI = 0.95-1.00) in association with annual differences in prey density; the slope coefficient for the additive effect of prey density on survival was 1.12 (95% CI = 0.06-2.19). Survival declined to 0.71 (95% CI = 0.60-0.93) shortly after juveniles initiated dispersal (weeks 8-12 post-fledging) and moved to more open habitats at lower elevations. Survival was not closely associated with weather or territory-level parameters. A comparison of the predictions of environmental-, territory-, and individual-based models of survival demonstrated that food availability was the primary factor limiting juvenile survival. This finding indicates that forest management prescriptions designed to support abundant prey populations while providing forest structural conditions that allow goshawks to access their prey within breeding areas should benefit juvenile survival.