Molt-breeding overlap alters molt dynamics and behavior in zebra finches, Taeniopygia guttata castanotis
Molt-breeding overlap alters molt dynamics and behavior in zebra finches, Taeniopygia guttata castanotis
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DOI：
10.1242/jeb.065474
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发表时间：
2012-06-01
影响因子：
2.8
通讯作者：
Hau, Michaela
中科院分区：
文献类型：
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作者：
Echeverry-Galvis, Maria A.;Hau, Michaela
生物体生命史周期中代价高昂的事件，如繁殖、迁移和毛皮/羽毛更换，通常在时间上分开，以最大限度地提高其结果。这种时间分离被认为是能量权衡所必需的，并通过生理过程介导。然而，某些物种，如热带鸟类，能够重叠两个昂贵的生命史阶段：繁殖和羽毛更换。目前尚不清楚这两个事件在长时间内同时发生时的进展情况。在这里，我们确定了这种重叠的后果和潜在的成本，通过比较蜕皮和行为模式，在两种性别的圈养斑胸草雀（Taeniopygia guttata castanotis），单独蜕皮或重叠繁殖和蜕皮。与处于换羽期但没有繁殖的鸟类相比，处于繁殖早期阶段的个体的羽毛生长速度下降了大约40%。此外，重叠繁殖和蜕皮的个体倾向于同时蜕皮较少的羽毛，并且在尾部或同一翅膀上脱落连续羽毛之间的间隔较长，以及在相对两侧脱落相应的飞羽的延迟。重叠的个体也改变了他们的时间预算：与只蜕皮的个体相比，他们花了两倍多的时间喂养，而花在羽毛护理上的时间减少了一半。这些数据为以前未经检验的假设提供了实验支持，即当蜕皮和繁殖时间重叠时，羽毛替换将以较慢和较低的速度发生。在评估的任何变量中没有性别差异，除了在重叠期间女性身体状况随时间下降的趋势比男性更强烈。我们的数据表明，重叠繁殖和蜕皮的主要后果的存在，表现在两个蜕皮动态和两性的时间预算的变化。在自然环境中更严酷的条件下，这种后果可能会更严重，并可能导致健身后果。
Costly events in the life history cycle of organisms such as reproduction, migration and pelage/plumage replacement are typically separated in time to maximize their outcome. Such temporal separation is thought to be necessitated by energetical trade-offs, and mediated through physiological processes. However, certain species, such as tropical birds, are able to overlap two costly life history stages: reproduction and feather replacement. It has remained unclear how both events progress when they co-occur over extended periods of time. Here we determined the consequences and potential costs of such overlap by comparing molt and behavioral patterns in both sexes of captive zebra finches (Taeniopygia guttata castanotis) that were solely molting or were overlapping breeding and molt. Individuals overlapping the early stages of breeding with molt showed a roughly 40% decrease in the growth rate of individual feathers compared with birds that were molting but not breeding. Further, individuals that overlapped breeding and molt tended to molt fewer feathers simultaneously and exhibited longer intervals between shedding consecutive feathers on the tail or the same wing as well as delays in shedding corresponding flight feathers on opposite sides. Overlapping individuals also altered their time budgets: they devoted more than twice the time to feeding while halving the time spent for feather care in comparison to molt-only individuals. These data provide experimental support for the previously untested hypothesis that when molt and reproduction overlap in time, feather replacement will occur at a slower and less intense rate. There were no sex differences in any of the variables assessed, except for a tendency in females to decline body condition more strongly over time during the overlap than males. Our data indicate the existence of major consequences of overlapping breeding and molt, manifested in changes in both molt dynamics and time budgets of both sexes. It is likely that under harsher conditions in natural environments such consequences will be more severe and may result in fitness consequences.