Ecol Evol. 2012 Jul;2(7):1426-36. doi: 10.1002/ece3.264.
Schultesia nitor is a gregarious species living in Cacicus and Psarocolius ssp. pouch-like nests. Due to gregariousness, opportunities for multiple copulations in both sexes are not supposed to be restricted. Females produce only one brood during their life and die within a few days following the birth of their nymphs, but this unique brood could be the result of either single or multiple mating events (i.e., monandry vs. polyandry). In this study, we first determined the age of sexual receptivity of both males and females. Larval development in this species is shorter in males than in females and thus, this species is protandric. Males were not able to copulate the day after emergence. Contrary to males, teneral females (i.e., females achieving their imaginal molt but not yet fully sclerotised and colored) were attractive and were able to mate with males. In the second experiment, we tested the existence of multiple matings in both sexes. Our results showed that females were monandrous whereas males were polygynous. Since we had observed that females were monoandrous, we expected them to be choosy and we determined their ability to discriminate between virgin and nonvirgin males. When given the choice, females preferred virgin males and overall, they were more successful at mating than experienced ones. Our results suggest that monandry may be primarily driven by the female's short life-span fecundity. The occurrence of teneral mating in this species calls into question the existence of a male strategy for monopolizing females, and as well as the implication of female choice. Although further work is required, this species provides an interesting model for understanding sexual conflicts.
黑头美洲咬鹃是一种群居性物种,生活在 Cacicus 和 Psarocolius 亚种的袋状巢中。由于群居性,雌雄两性的多次交配机会不应受到限制。雌性一生中只产一窝,在幼崽出生后的几天内死亡,但这种独特的窝可能是单次或多次交配的结果(即单配和多配)。在这项研究中,我们首先确定了雌雄两性的性接受年龄。该物种的幼虫发育在雄性中比在雌性中更短,因此,该物种是先熟雄的。雄性在出现后的第二天无法交配。与雄性相反,未成熟的雌性(即刚完成羽化但尚未完全骨化和着色的雌性)具有吸引力,能够与雄性交配。在第二个实验中,我们测试了两性中多次交配的存在。我们的结果表明,雌性是单配的,而雄性是多配的。由于我们观察到雌性是单配的,我们期望它们具有选择性,并确定它们区分处女和非处女雄性的能力。当有选择时,雌性更喜欢处女雄性,总体而言,它们比有经验的雄性更成功地交配。我们的结果表明,单配可能主要是由雌性的短寿命生育力驱动的。在该物种中发生的未成熟交配质疑了雄性垄断雌性的策略的存在,以及雌性选择的含义。尽管还需要进一步的工作,但该物种为理解性冲突提供了一个有趣的模型。