The hormonal milieu that exists during reproduction is one of the key factors influencing the trade-off between reproductive investment and self-maintenance. Much previous work in birds has focused on prolactin as a physiological mediator since prolactin is involved in the onset and maintenance of parental care. However, how prolactin relates to reproductive success in terms of altering parental behavior in wild bird populations is not fully understood. Here, we report prolactin concentrations in breeding Kentish plovers (Charadrius alexandrinus), a small shorebird with variable mating systems and parental care, as an ecological model of mating system evolution. Throughout the breeding season, we estimated the circulating prolactin concentrations in male and female plovers during incubation. In addition, we monitored parental behavior and determined the fate of nests. We found that prolactin concentrations decreased during incubation but increased with clutch completion date. In addition, males and females with high prolactin concentrations spent more time on incubation than those with low prolactin concentrations. Importantly, higher prolactin concentrations in either males or females predict higher nest survival. Our results suggest that prolactin is an indicator of parental behavior in a wild shorebird population, although additional studies including experimental manipulation of prolactin concentrations are necessary to verify this relationship.

中文翻译：

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催乳素的浓度可以预测父母的投资以及自由生活的水鸟的巢生存。

生殖过程中存在的荷尔蒙环境是影响生殖投资与自我维持之间权衡的关键因素之一。由于泌乳素参与了父母护理的开始和维持，以前在鸟类中进行的许多工作都将催乳素作为一种生理介质。然而，就改变野生鸟类种群的亲代行为而言，催乳素与生殖成功之间的关系尚不完全清楚。在这里，我们报告了繁殖肯特郡三叶草（Charadrius alexandrinus）中的催乳素浓度，这是一种具有可变交配系统和父母关怀的小型水鸟，是交配系统进化的生态模型。在整个繁殖季节，我们估算了孵化过程中雄性和雌性三叶草中循环催乳素的浓度。此外，我们监控了父母的行为，并确定了巢穴的命运。我们发现，催乳素的浓度在孵育过程中降低，但随着离体完成日期的增加而升高。此外，高催乳素浓度的男性和女性比低催乳素浓度的男性和女性在孵化上花费的时间更多。重要的是，雄性或雌性中较高的催乳素浓度预示着较高的巢存活率。我们的结果表明，催乳素是野生水鸟种群中父母行为的指标，尽管需要进行其他实验，包括实验性控制催乳素浓度，以验证这种关系。催乳素浓度高的雄性和雌性比低催乳素浓度的雄性在孵化上花费更多的时间。重要的是，雄性或雌性中较高的催乳素浓度预示着较高的巢存活率。我们的结果表明，催乳素是野生水鸟种群中父母行为的指标，尽管需要进行其他研究，包括对催乳素浓度进行实验性操作，以验证这种关系。催乳素浓度高的雄性和雌性比低催乳素浓度的雄性在孵化上花费更多的时间。重要的是，雄性或雌性中较高的催乳素浓度预示着较高的巢存活率。我们的结果表明，催乳素是野生水鸟种群中父母行为的指标，尽管需要进行其他实验，包括实验性控制催乳素浓度，以验证这种关系。