DISSERTATION RESEARCH: Implications of Adult Incubation Behavior on Embryo Growth and Metabolism

博士论文研究：成人孵化行为对胚胎生长和代谢的影响。Olson和Carol M.孵化鸡蛋的鸟类必须在维持胚胎生长所需的鸡蛋温度和花费时间觅食之间分配时间。 人们早就知道，鸡蛋成功孵化的热条件范围很窄。 然而，许多小型鸣禽的蛋经常经历广泛的温度波动时，成年人离开他们的巢觅食，但蛋孵化成功。 鸟类的孵化行为各不相同。 在某些物种中，父母双方都孵化，蛋很少冷却。 在其他物种中，只有雌性孵化，当雌性离开巢穴觅食时，会导致卵的间歇性冷却。 这表明，一些鸟类胚胎已经进化出耐热性，也就是说，它们能够在冷却过程中存活下来，并仍然保持正常的生长。本研究的总体目标是描述卵的温度分布与孵化成虫的孵化策略之间的关系。 它将包括在实验室进行的两个关于胚胎对间歇性冷却的生理和发育反应的实验和一个田间实验。 1.代谢斑胸草雀（Taeniopygia guttata）蛋将在模拟冷却和复温的较量，以确定胚胎代谢反应，以不同程度的情节冷却。 2.将检查整个发育过程中偶发性降温的表型和生存后果。 然后，这些知识将扩展到该领域，以研究成年和胚胎鸟类所承受的约束和限制。 3.将增加或减少家鹪鹩（Troglodytes aedon）卵的冷却速率，并监测成虫的反应。 当冷却速度增加时，预计成年人会通过转向有利于蛋的行为来补偿，主要是在巢上花费更多的时间。 然而，当降温速度降低时，成年人应该花更多的时间寻找食物。 结合这三个实验的结果将有助于了解卵的热生理学如何限制成虫的孵化行为和繁殖生物学。

Dissertation Research: Implications of Adult Incubation Behavior on Embryo Growth and MetabolismChristopher R. Olson and Carol M. VleckIowa State UniversityBirds incubating eggs must allocate time between maintaining egg temperatures required for embryonic growth and spending time foraging for food. It has long been known that the range of thermal conditions for eggs to hatch successfully is narrow. However, the eggs of many small songbirds frequently undergo wide thermal fluctuations when the adults leave their nests to forage, and yet the eggs hatch successfully. Birds vary in their incubation behaviors. In some species both parents incubate and eggs seldom cool. In other species only the female incubates, resulting in episodic cooling of the eggs when the female leaves the nest to forage. This suggests that some avian embryos have evolved thermal tolerance, that is, they are able to survive episodes of cooling and still maintain normal growth. This study's general goal is to describe the relationship between the thermal profile of the eggs and the incubation strategy of the incubating adult. It will incorporate two experiments carried out in the lab on the physiological and developmental responses of embryos to episodic cooling and one field experiment. 1. Metabolism of zebra finch (Taeniopygia guttata) eggs will be examined during simulated cooling and rewarming bouts to define the embryonic metabolic response to different degrees of episodic cooling. 2. The phenotypic and survival consequences of episodic cooling throughout development will be examined. This knowledge will then be extended to the field to study constraints and limitations that both adult and embryonic birds endure. 3. Cooling rates of house wren (Troglodytes aedon) eggs will be increased or decreased and adult response monitored. When cooling rates are increased, adults are predicted to compensate by shifting to behaviors that benefit the eggs, mainly spending increased time on the nest. However, when cooling rates are decreased, adults should spend more searching for food. Combining the results of these three experiments will aid in understanding how egg thermal physiology places limits on adult incubation behavior and breeding biology.