Department of Biological Sciences and Edward J. Meeman Biological Station, University of Memphis, Memphis, TN, USA.
Sci Rep. 2019 Mar 26;9(1):5161. doi: 10.1038/s41598-019-41690-4.
It is widely accepted that recent increases in environmental temperature have had a causal effect on changing life histories; however, much of the evidence for this is derived from long-term observations, whereas inferences of causation require experimentation. Here, we assess effects of increased environmental temperature during incubation on posthatching development, nestling begging and parental care, and reproductive success in two wild, cavity-nesting songbirds, the Carolina wren and prothonotary warbler. We heated experimental nests only during incubation, which increased nest-cavity temperature by ca. 1 °C. This reduced the length of the incubation and nestling periods, and reduced fledging success in prothonotary warblers, while nestling Carolina wrens had similar fledging success but reduced body condition in response to increased temperature. Increased nest-cavity temperature during incubation also reduced posthatching begging by nestlings generally and parental care within Carolina wrens specifically, suggesting potential mechanisms generating these carry-over effects. Offspring body mass and fledging age are often predictive of post-fledging survival and recruitment. Thus, our results suggest that increasing temperatures may affect fitness in wild populations in species-specific ways, and induce life-history changes including the classic trade-off parents face between the size and number of offspring.
人们普遍认为，环境温度的最近升高对生物生活史的变化有因果影响；然而，这种影响的大部分证据来自长期观察，而因果关系的推断则需要实验。在这里，我们评估了在两种野生洞穴筑巢的鸣禽——卡罗莱纳鹪鹩和黄喉地莺中，孵化期间环境温度升高对出壳后发育、雏鸟乞食和亲鸟育雏以及繁殖成功率的影响。我们仅在孵化期间加热实验巢，将巢腔温度升高约 1°C。这缩短了孵化和育雏期，并降低了黄喉地莺的出飞成功率，而巢中卡罗莱纳鹪鹩的出飞成功率相似，但体温升高导致其身体状况变差。孵化期间巢腔温度升高还普遍降低了雏鸟的出壳后乞食行为，以及卡罗莱纳鹪鹩的亲鸟育雏行为，这表明可能存在产生这些滞后效应的机制。后代的体重和出飞年龄通常可以预测出飞后的存活率和补充率。因此，我们的研究结果表明，温度升高可能以特定于物种的方式影响野生动物种群的适应性，并诱导生活史变化，包括父母在后代大小和数量之间面临的经典权衡。
