Testing mating systems theory in a polygynous model system: the reindeer/caribou (Rangifer tarandus)

在过去的几十年里，许多模型试图为交配系统开发一个预测框架。然而，在该领域量化性选择和测试交配系统理论已被证明是困难的。我的目标是用实验方法来检验交配系统理论的关键预测。我将操纵女性密度，食物分散，和操作性比（OSR），以评估它们如何影响交配组动态和交配策略。有蹄类动物是研究交配系统进化的极好模型系统，因为它们在性二态性方面具有最高的变异性，并且因为它们最少的父亲照顾和交配系统的巨大变异性。我使用驯鹿（Rangifer tarandus）从一个特殊的人口，所有个人将安装GPS项圈和操纵是可能的，因为我的模型系统。具体来说，我们将测试：（i）平均群体大小，裂变率，融合率和斑块（ii）雌性聚集在食物斑块，导致更高的平均群体大小和斑块在聚集比分散的治疗;（3）集群处理和分散处理的雄性交配策略不同，集群处理的雄性交配策略具有资源防御性，分散处理的雄性交配策略具有独占性，这是雄性交配策略可塑性的基础;（iv）斑块与性选择机会之间的相关性是正的;以及（v）雄性对雄性的攻击性是否随着OSR而增加，而雌性对雌性的攻击性是否减少;求爱率随着OSR而下降，因为雄性对雄性的竞争增加。通过使用完全受控的基于GPS的种群，我的研究将严格测试驯鹿交配系统理论的关键预测，并显示是否可以通过操纵当地环境来最大限度地减少竞争强度。该研究具有管理的意义，显示密度依赖的影响，男性交配成功和人口生产力的分布，并提供必要的信息，长期保护。因此，这项工作提供了对人口调节机制的深入了解。

Over the past several decades, many models have attempted to develop a predictive framework for mating systems. However, quantifying sexual selection and testing mating systems theory in the field have proven difficult. My aim is to use an experimental approach to test the key predictions of mating systems theory. I will manipulate female density, food dispersion, and operational sex ratio (OSR) to assess how they influence mating group dynamics and mating tactics. Ungulates are excellent model systems to study the evolution of mating systems because they have the highest variability in sexual dimorphism, and because of their minimal paternal care and great variability in mating systems. I use reindeer (Rangifer tarandus) from an exceptional population where all individuals will be fitted GPS collars and manipulation is possible as my model system. Specifically we will test whether : (i) the average group size, the rate of fission, the rate of fusion, and patchiness (a measure of the degree to which females are clumped in space), increase with density; (ii) females aggregate at food patches, leading to higher average group size and patchiness in clumped than dispersed treatments; (iii) males mating strategy differs between the clumped and dispersed treatments, with resource defense in the clumped treatment and monopolization in the dispersed treatment, underlying the plasticity of mating strategies; (iv) the correlation between patchiness and the opportunity for sexual selection is positive; and whether (v) male-male aggression increases with OSR whereas female-female aggression decreases; and courtship rate decreases with OSR, because of increased male-male competition. By using a fully-controlled GPS-based population, my research will rigorously test key predictions of mating systems theory on reindeer and show whether the intensity of competition can be minimized by manipulating the local environment. The research has management implications by showing density-dependent influence on the distribution of male mating success and population productivity, and by providing information necessary for long term conservation. The work, therefore, provides insight into the mechanisms of population regulation.