Direct and indirect effects of high temperatures on fledging in a cooperatively breeding bird
Direct and indirect effects of high temperatures on fledging in a cooperatively breeding bird
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DOI：
10.1093/beheco/arab087
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发表时间：
2021-07-20
影响因子：
2.4
通讯作者：
Cunningham, Susan J.
中科院分区：
文献类型：
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作者：
Bourne, Amanda R.;Ridley, Amanda R.;Cunningham, Susan J.
高温和少雨一直限制着干旱地区鸟类的繁殖。了解这种模式背后的机制对于预测气候变化将如何影响种群持久性以及为保护和管理提供信息至关重要。本研究分析了南方夏季三个繁殖期南方斑花鸟（Southern Pied Babbler Turdoides）的雏鸟成活率、日生长率和成虫投资行为。高温会导致雏鸟体重降低、跗关节变短、日生长率降低。我们的分段结构方程模型表明，温度的直接影响对5日龄和11日龄雏鸟的雏鸟尺寸和日生长率的影响最大，其次是成鸟对温度相关的供给率的调节。降雨和群体大小对供给成虫的行为有影响，但对雏鸟的生长和存活没有影响。成虫供给策略的调整并不能补偿高温对雏鸟体型或日生长率的直接负面影响。像这样的详细的机制数据使我们能够模拟高温导致巢破坏的途径。反过来，这可以让我们设计有针对性的保护行动，有效地减轻气候影响。
High temperatures and low rainfall consistently constrain reproduction in arid-zone bird species. Understanding the mechanisms underlying this pattern is critical for predicting how climate change will influence population persistence and to inform conservation and management. In this study, we analyzed Southern Pied Babbler Turdoides bicolor nestling survival, daily growth rate and adult investment behavior during the nestling period over three austral summer breeding seasons. High temperatures were associated with lower body mass, shorter tarsi, and reduced daily growth rates of nestlings. Our piecewise structural equation models suggested that direct impacts of temperature had the strongest influence on nestling size and daily growth rates for both 5-day-old and 11-day-old nestlings, followed by temperature-related adjustments to provisioning rates by adults. Rainfall and group size influenced the behavior of provisioning adults but did not influence nestling growth or survival. Adjustments to adult provisioning strategies did not compensate for direct negative effects of high air temperatures on nestling size or daily growth rates. Detailed mechanistic data like these allow us to model the pathways by which high temperature causes nest failure. In turn, this could allow us to design targeted conservation action to effectively mitigate climate effects.