Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX 77843, USA.
Department of Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY 10027, USA.
Integr Comp Biol. 2022 Aug 13;62(1):9-20. doi: 10.1093/icb/icac018.
Female competitive behaviors during courtship can have substantial fitness consequences, yet we know little about the physiological and social mechanisms underlying these behaviors-particularly for females of polygynous lek mating species. We explored the hormonal and social drivers of female intersexual and intrasexual behavior during courtship by males in a captive population of Indian peafowl. We investigated whether (1) female non-stress induced circulating estradiol (E2) and corticosterone (CORT) levels or (2) female dominance status in a dyad predicts female solicitation behavior. We also tested whether female circulating E2 and CORT predict dominant females' aggressive behaviors toward subordinate females in the courtship context. Our findings demonstrate that females with higher levels of circulating E2 as well as higher levels of circulating CORT solicit more courtships from males. Dominant females also solicit more courtships from males than subordinate females. Female intrasexual aggressive behaviors during courtship, however, were not associated with circulating levels of E2 or CORT. Overall, we conclude that circulating steroid hormones in conjunction with social dominance might play a role in mediating female behaviors associated with competition for mates. Experimental manipulation and measures of hormonal flexibility throughout the breeding season in relation to competitive and sexual behaviors will be necessary to further examine the link between hormonal mechanisms and female behavior in polygynous lekking systems.
雌性在求偶期间的竞争行为可能会对其适应度产生重大影响,但我们对这些行为背后的生理和社会机制知之甚少——特别是对于多配偶制的地栖鸟类交配物种的雌性而言。我们通过对圈养的印度孔雀种群中的雄性进行研究,探索了雌性在求偶期间的两性间和同性间行为的激素和社会驱动因素。我们调查了以下两个问题:(1)雌性非应激诱导的循环雌二醇(E2)和皮质酮(CORT)水平,或(2)雌性在对偶中的支配地位是否可以预测雌性的求偶行为。我们还测试了雌性的循环 E2 和 CORT 是否可以预测支配地位的雌性在求偶环境中对从属地位的雌性的攻击行为。我们的研究结果表明,循环 E2 水平较高和循环 CORT 水平较高的雌性会向雄性发出更多的求偶信号。支配地位的雌性向雄性发出的求偶信号也比从属地位的雌性更多。然而,雌性在求偶期间的同性间攻击行为与循环 E2 或 CORT 水平无关。总的来说,我们得出的结论是,循环类固醇激素与社会支配地位可能共同在调节与争夺配偶相关的雌性行为方面发挥作用。在繁殖季节中进行激素灵活性的实验操作和测量,并结合竞争和性行为,将有助于进一步研究激素机制与多配偶制地栖鸟类交配系统中雌性行为之间的联系。