Past reproductive effort allows males to assess their ability to acquire mates, but it also consumes resources that can reduce their future competitive ability. Few studies have examined how a male’s reproductive history affects his subsequent mate choice; and, to date, no study has determined the relative contribution of past mating behavior and past ejaculate production because these two forms of investment are naturally highly correlated. Here, we disentangled the relative effects of past mating behavior and past ejaculate production in mosquitofish (Gambusia holbrooki) by experimentally preventing some males from ejaculating when trying to mate. We assessed the effect of mating behavior on mate choice by comparing males that had previously been with or without access to females and male rivals for 8 and 16 weeks; and assessed the effect of ejaculation on mate choice by comparing males that either could or could not ejaculate when they had access to females for 16 weeks. Reproductive treatment did not affect male attractiveness, but it did affect male mate choice. Somewhat surprisingly, in 5 of the 6 treatment-age at testing combinations, males preferred a female in the vicinity of a male rival over a solitary female. This preference was marginally stronger for males that had previously engaged in mating behavior but was unaffected by past ejaculate production. We discuss the potential benefits to males of associating with another male when seeking mates. This is the first study to quantify the relative influence of pre- and post-copulatory reproductive investment on male mate choice.

中文翻译：

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过去的交配行为与过去的射精对男性择偶和男性吸引力的影响

过去的繁殖努力可以让雄性评估他们获得配偶的能力，但它也会消耗资源，从而降低他们未来的竞争能力。很少有研究探讨男性的生育史如何影响其随后的择偶选择。迄今为止，还没有研究确定过去的交配行为和过去的射精产生的相对贡献，因为这两种形式的投资本质上是高度相关的。在这里，我们通过实验阻止一些雄性试图交配时射精，理清了食蚊鱼（Gambusia holbrooki）过去交配行为和过去射精产生的相对影响。我们通过比较雄性在8周和16周内是否接触过雌性和雄性竞争对手，评估了交配行为对择偶的影响。通过比较雄性在与雌性接触 16 周后是否能够射精，评估了射精对择偶的影响。生殖治疗并不影响男性的吸引力，但确实影响了男性的择偶选择。有点令人惊讶的是，在测试组合的 6 个治疗年龄中有 5 个中，雄性更喜欢在雄性竞争对手附近的雌性，而不是孤独的雌性。对于之前有过交配行为但未受过去射精影响的雄性来说，这种偏好稍强一些。我们讨论了雄性在寻找配偶时与另一只雄性交往的潜在好处。这是第一项量化交配前和交配后生殖投资对雄性择偶的相对影响的研究。