Department of Ethology, Eötvös Loránd University, Budapest 1117, Pázmány Péter sétány 1/c, Hungary.
Horm Behav. 2012 May;61(5):734-40. doi: 10.1016/j.yhbeh.2012.03.011. Epub 2012 Mar 31.
One of the fundamental principles of the life-history theory is that parents need to balance their resources between current and future offspring. Deserting the dependent young is a radical life-history decision that saves resources for future reproduction but that may cause the current brood to fail. Despite the importance of desertion for reproductive success, and thus fitness, the neuroendocrine mechanisms of brood desertion are largely unknown. We investigated two candidate hormones that may influence brood desertion in the Kentish plover Charadrius alexandrinus: prolactin ('parental hormone') and corticosterone ('stress hormone'). Kentish plovers exhibit an unusually diverse mating and parental care system: brood desertion occurs naturally since either parent (the male or the female) may desert the brood after the chicks hatch and mate with a new partner shortly after. We measured the hormone levels of parents at hatching using the standard capture and restraint protocol. We subsequently followed the broods to determine whether a parent deserted the chicks. We found no evidence that either baseline or stress-induced prolactin levels of male or female parents predicted brood desertion. Although stress-induced corticosterone levels were generally higher in females compared with males, individual corticosterone levels did not explain the probability of brood desertion. We suggest that, in this species, low prolactin levels do not trigger brood desertion. In general, we propose that the prolactin stress response does not reflect overall parental investment in a species where different parts of the breeding cycle are characterized by contrasting individual investment strategies.
生命史理论的基本原则之一是，父母需要在当前和未来的后代之间平衡资源。抛弃依赖的幼崽是一种激进的生活史决策，它可以为未来的繁殖节省资源，但可能导致当前的一窝幼崽失败。尽管遗弃对繁殖成功（即适应度）很重要，但弃巢的神经内分泌机制在很大程度上尚不清楚。我们研究了两种可能影响肯特滨鹬 Charadrius alexandrinus 弃巢的候选激素：催乳素（“亲代激素”）和皮质酮（“应激激素”）。肯特滨鹬表现出一种异常多样化的交配和育雏系统：由于雄性或雌性亲代在雏鸟孵化后可能会弃巢，并在短时间内与新伴侣交配，因此自然会发生弃巢现象。我们使用标准的捕获和限制协议在孵化时测量亲代的激素水平。随后，我们跟踪这些鸟巢以确定亲代是否抛弃了雏鸟。我们没有发现证据表明雄性或雌性亲代的基础或应激诱导催乳素水平预测了弃巢行为。尽管雌性的应激诱导皮质酮水平通常高于雄性，但个体皮质酮水平并不能解释弃巢的概率。我们认为，在这种物种中，低催乳素水平不会引发弃巢行为。总的来说，我们提出，在繁殖周期的不同阶段具有不同的个体投资策略的物种中，催乳素应激反应并不反映总体亲代投资。
