Coercive mating by overwintering male monarch butterflies
Coercive mating by overwintering male monarch butterflies
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越冬雄性帝王蝶强制交配
DOI：
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发表时间：
2012
期刊：
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通讯作者：
D. Frey
中科院分区：
文献类型：
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作者：
K. Oberhauser;D. Frey
我们研究了越冬帝王蝶交配行为的两个方面：强制求爱行为以及越冬期间交配的发生和时间。大约三分之一的雄性与雌性交配尝试以交配为结果，并且尝试的持续时间从一秒到超过 30 分钟不等。大约四分之一的尝试涉及两名男性，并且男性对男性的尝试与男性对女性的尝试一样长。先前交配过的雌性的交配尝试时间比未交配的雌性的交配时间要长。交配雄性的状况比栖息雄性差，墨西哥交配雌性比栖息雌性更大。我们使用成本/收益模型来解释这些结果。我们认为，冬季交配的回报对于两性来说可能都很低。雌性很有可能会再次交配，而帝王蝶中最后雄性精子的优先权意味着在冬季交配期间转移的精子很可能会被随后的交配所取代。从雌性的角度来看，交配的成本（携带额外的精子量和可能的物理损伤）可能不会被冬季交配的好处所抵消。我们认为，由于交配过于频繁或在前一次交配后过早而遭受交配囊破裂的代价的雌性可能会在随后的交配中挣扎更长时间，而状况不佳的雄性更愿意交配，从而导致未来的适应度降低，因为它们在以后的交配中存活的机会较小。墨西哥的雄性可能会选择体型较大的雌性，尽管雄性之间普遍存在的尝试表明雄性并没有太大的歧视性。我们认为，帝王蝶中的雄性胁迫是在越冬的背景下进化而来的。在越冬地点，未来繁殖成功率较低的雄性与雌性共存，雌性通过交配几乎没有获得什么好处，但与面临需要最大限度地延长产卵时间压力的夏季雌性相比，由于意外交配而造成的损失也更少。
We studied two aspects of ma ting behavior in overwintering monar ch butterflies: their coer cive courtship behavior, and the occur rence and timing of ma ting during the overwintering period. Approximately one third of male-f emale mating attempts r esulted in coupling , and the dur ation of attempts r anged from one second to o ver 30 minutes. About one quar ter of all attempts involved two males, and male-male a ttempts were as long as male-f emale attempts. Mating attempts involving previously-mated females were longer than those in volving virgin females. Ma ting males were in poor er condition than r oosting males,and mating females in Me xico were larger than r oosting females. We use a cost/benef it model to interpret these r esults. We argue that the payoff of winter mating is probably low for both sexes. There is a good chance tha t females will r emate, and last-male sper m precedence in monar chs means tha t sperm transferred during winter matings are likely to be super seded by subsequent ma tings. From the f emale per spective, the costs of ma ting (carying the aditional mass of a sper matophore and possib le physical damage) may not be of fset by benef its of winter matings. We suggest that females tha t could sufer the cost of a r uptured bursa copulatrix from mating too often or too soon after a pr evious mating are likely to struggle longer in a subsequent ma ting, and that males in poor condition ar e more willing to mate and thus incur r educed future fitness since the y have a smaller c hance of sur viving to mate later. Males in Mexico may be selecting large females,although the pr evalence of male-male a ttempts ar gues that males ar e not very discriminatory. We propose tha t male coer cion in monar chs evolved in the conte xt of overwintering. At overwintering sites, males with low prospects f or future reproductive success co-occur with f emales tha t have little to gain by mating, but less to lose fr om unwanted matings than summer f emales who face the pr essur e of needing to maximize time for oviposition.