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

论文研究：成虫孵化行为对胚胎生长和新陈代谢的影响克里斯托弗·R·奥尔森和卡罗尔·M·弗莱克爱荷华州立大学孵化鸡蛋的鸟类必须在保持胚胎生长所需的蛋温和花费时间觅食之间分配时间。很早就知道，卵成功孵化的温度条件范围很窄。然而，当成年鸣禽离开巢去觅食时，许多小型鸣禽的蛋经常经历广泛的温度波动，但蛋成功孵化。鸟类的孵化行为各不相同。在一些物种中，双亲都孵化，卵很少冷却。在其他物种中，只有雌性孵化，导致当雌性离开巢去觅食时，卵会时不时地冷却。这表明，一些禽类胚胎已经进化出耐热性，也就是说，它们能够在降温期间存活下来，并仍然保持正常生长。这项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。它将包括两个在实验室进行的关于胚胎对间歇性降温的生理和发育反应的实验，以及一个现场实验。1.在模拟降温和复温过程中，对斑雀卵的代谢进行了研究，以确定胚胎对不同程度降温的代谢反应。2.将研究在整个发育过程中间歇性冷却的表型和生存后果。然后，这一知识将扩展到该领域，以研究成年和胚胎鸟类所承受的限制和限制。3.提高或降低家禽卵的降温速度，监测成虫的反应。当降温速度加快时，成虫预计会通过改变有利于卵子的行为来进行补偿，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，将有助于理解鸡蛋热生理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.