The capital and income breeding concept links energy resources used during reproduction to the timing of their acquisition. During reproduction, capital breeders rely on resources gained previously and accumulated for reproductive investment. By contrast, income breeders use mainly resources collected during the period of reproductive activity. Most commonly, this concept is applied to females; relatively few studies have considered males. Moreover, there has been little attention to the link between the capital-income divide and other aspects of mating strategy. We studied adult males of three wild ungulates with different levels of polygyny. A large dataset (4,264 red deer, 53,619 roe deer, and 13,537 Alpine chamois, respectively) was obtained during 2007–2017 in the whole territory of Slovenia and in the Trento province, Italy. During the rut, body mass loss of males in highly polygynous species was more than twice that of weakly polygynous species: on average, red deer stags lost 19.5%; chamois bucks 16.0%; and roe deer bucks 7.5% of their body mass. This indicates potential for a hitherto unrecognized link between the degree of intrasexual competition and the degree of capital mating. The variability in body mass at the end of the rut was clearly reduced in both highly polygynous species (from 15.1 to 9.4% in red deer, and from 12.5 to 10.5% in chamois), but did not change in roe deer. Finally, roe deer bucks had recovered body mass to that of the pre-rut period by just 2 months after the rut, while red deer stags did not manage to compensate the loss of weight until the end of the year. We suggest that, at least in ungulates, there is a link between the degree of polygyny and that of capital breeding. Males of capital and income breeders underwent body mass changes resulting from different reproductive investment during the rut. Capital breeders lost considerably more weight, and invested a variable amount of energy among individuals or among years, possibly to cope with different environmental or body conditions. In so doing, they ended the rut with poorer but more even condition among individuals.

中文翻译：

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雄性有蹄类动物的资本收入繁殖：物种间策略差异的原因和后果

资本和收入繁殖概念将繁殖过程中使用的能源资源与其获取时间联系起来。在繁殖过程中，资本育种者依靠先前获得的资源并积累起来进行繁殖投资。相比之下，收入育种者主要使用繁殖活动期间收集的资源。最常见的是，这个概念适用于女性；相对较少的研究考虑了男性。此外，很少有人关注资本收入差距与交配策略其他方面之间的联系。我们研究了三只具有不同程度的一夫多妻的野生有蹄类动物的成年雄性。2007-2017 年在斯洛文尼亚全境和意大利特伦托省获得了一个大型数据集（分别为 4,264 只马鹿、53,619 只狍子和 13,537 只高山羚羊）。在车辙期间，高度一夫多妻物种中雄性的体重损失是弱一夫多妻物种的两倍多：平均而言，马鹿雄鹿损失了 19.5%；麂皮 16.0%；狍的体重占其体重的 7.5%。这表明性内竞争程度与资本交配程度之间存在迄今为止未被认识的潜在联系。两种高度一夫多妻的物种（从马鹿的 15.1% 到 9.4%，羚羊的从 12.5% 到 10.5%），车辙结束时体重的变异性明显降低，但狍子没有变化。最后，狍子在发情后仅两个月就恢复到发情前的体重，而马鹿直到年底才设法弥补体重的损失。我们建议，至少在有蹄类动物中，一夫多妻制的程度与资本繁殖的程度之间存在联系。资本和收入育种者的雄性在发情期间经历了不同的生殖投资导致的体重变化。资本饲养者减掉了更多的体重，并在个体之间或在不同年份之间投入了不同数量的能量，可能是为了应对不同的环境或身体状况。通过这样做，他们结束了个人之间更差但更均衡的情况。