Hopkins Brittney Cole, Durant Sarah Elizabeth, Hepp Gary Richard, Hopkins William Alexander
Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, USA.
J Exp Zool A Ecol Genet Physiol. 2011 Jun 1;315(5):274-9. doi: 10.1002/jez.673. Epub 2011 Mar 1.
Incubation temperature is an important maternal effect in birds that can influence numerous offspring traits. For example, ducklings from eggs incubated at lower temperatures have lower growth rates, protein content, and are in poorer body condition than ducklings from eggs incubated at higher temperatures. Based on these observations, we predicted that incubation temperature would indirectly influence performance through its direct effects on body size. Wood duck (Aix sponsa) eggs were incubated at three ecologically relevant temperatures (35, 35.9, 37°C). After hatching, all ducklings were housed under identical conditions and were subjected to aquatic and terrestrial racing trials at 15 and 20 days posthatch (dph). Contrary to our prediction, incubation temperature did not influence most duckling body size parameters at 15 or 20 dph. However, incubation temperature did have a strong influence on locomotor performance independent of body size and body condition. Ducklings hatched from eggs incubated at the lowest temperature had significantly reduced maximum aquatic swim velocity than ducklings from higher temperatures. Maximum terrestrial sprint velocity followed a similar pattern, but did not differ statistically among incubation treatments. To our knowledge, this is the first study to demonstrate that slight changes in incubation temperature can directly affect locomotor performance in avian offspring and thus provide a significant source of phenotypic variation in natural wood duck populations.
孵化温度是鸟类中一种重要的母体效应，会影响众多后代性状。例如，与在较高温度下孵化的蛋所孵出的小鸭相比，在较低温度下孵化的蛋所孵出的小鸭生长速度较慢、蛋白质含量较低，身体状况也较差。基于这些观察结果，我们预测孵化温度会通过对体型的直接影响间接影响其表现。林鸳鸯（Aix sponsa）的蛋在三个与生态相关的温度（35、35.9、37°C）下孵化。孵化后，所有小鸭都在相同条件下饲养，并在孵化后15天和20天（dph）进行水上和陆地赛跑试验。与我们的预测相反，孵化温度在15或20 dph时并未影响大多数小鸭的体型参数。然而，孵化温度对运动表现有强烈影响，且与体型和身体状况无关。在最低温度下孵化的蛋所孵出的小鸭，其最大水上游泳速度比在较高温度下孵化的蛋所孵出的小鸭显著降低。最大陆地冲刺速度也呈现类似模式，但在不同孵化处理之间没有统计学差异。据我们所知，这是第一项证明孵化温度的微小变化可直接影响鸟类后代运动表现的研究，因此为野生林鸳鸯种群的表型变异提供了一个重要来源。
