A Comparative Study of Manakins at Leks: Consequences for Variance in Mating Success and Population Genetics

Leks的Manakins的比较研究：交配成功和种群遗传差异的后果Bette A.Loiselle，John G.Blake和Patricia G.Parker本项目调查了一组在新热带潮湿森林中表现出挑逗行为的近亲Manakin(鸟类：Pipridae)的空间结构、遗传亲缘关系和生殖倾斜之间的关系。觅食行为发生在许多动物类群中，其特征是雄性聚集在传统的位置上表现为雌性，交配后雄性和雌性之间缺乏联系。雌性访问Leks只是为了在没有雄性帮助的情况下在其他地方繁殖和抚养它们的幼崽。挑逗行为通常会导致雄性之间的巨大生殖差异(歪斜)，因为通常只有一只或几只雄性在LEK地点成功地与雌性交配。MANAKINS代表了一个研究繁殖偏差的模式系统，因为(1)鸟类是热带湿润森林林下的常见居民，(2)六个密切相关的物种出现在相同的地理位置，因此经历了相似的环境，(3)物种在LEK组织(例如，LEK的雄性数量和雄性之间的距离)和LEK行为方面不同，这是预测生殖偏差和分析LEK交配系统的种群遗传后果的关键。关于生殖不对称的理论已经出现了很多，但实证检验还很少。了解影响生殖倾斜的因素对于理解挑逗行为的进化至关重要。挑逗行为是一种交配系统，已经在许多分类群中进化，并在理论和经验文献中受到了极大的关注。衡量觅食物种生殖偏差的方法通常是基于对猎物交配的观察。然而，使用分子遗传学数据的亲子关系分析显示，对于许多鸟类物种来说，观察可能会提供关于父子关系的误导性结果。在这项拟议的研究中，通过对在巢中发现的后代进行亲子关系分析，将至少观察到的数据与个体雄性成功和生殖偏差的直接测量相结合。这项研究将首次比较一组密切相关的物种之间的取食行为及其遗传后果，这些物种出现在同一森林中，但取食的组织和空间结构不同。这种方法将有助于我们理解LEK交配系统的演化。拟议的研究还有效地结合了主要研究人员的生态、行为和分子遗传学专业知识，并为新的协作研究提供了途径，这将增强每个高级研究人员的研究计划。研究计划的实地和实验室部分将为来自本国机构和厄瓜多尔大学的学生提供获得研究经验的关键机会。几名厄瓜多尔人和UM-St。作为论文研究的一部分，路易学院的学生们将对提议项目的方方面面进行扩展。圣彼得堡大学在厄瓜多尔的旅费。路易斯的学生和教职员工将得到美国国家科学基金会国际科学与工程办公室的支持。

A Comparative Study of Manakins at Leks: Consequences for Variance in Mating Success and Population GeneticsBette A. Loiselle, John G. Blake, and Patricia G. ParkerAbstract This project investigates the relationship between spatial structure, genetic relatedness and reproductive skew in a set of closely related species of manakins (Aves: Pipridae) that exhibit lekking behavior in Neotropical wet forests. Lekking behavior, which occurs in many animal taxa, is characterized by a aggregation of males displaying for females in traditional locations and a lack of association between males and females after copulation. Females visit leks only to breed and rear their young elsewhere without assistance from the male. Lekking behavior often results in large reproductive variance (skew) among males because usually only one or a few males at the lek sites successfully copulate with females. Manakins represent a model system to investigate reproductive skew because (1) birds are common inhabitants of understory of tropical wet forests, (2) six closely related species occur in the same geographic location and thus experience similar environments, and (3) species differ in lek organization (e.g., number of males and distance among males at leks) and lekking behavior, characters key for predicting reproductive skew and analyzing population genetic consequences of lek mating systems. Considerable theory regarding reproductive skew has emerged, but there yet exist few empirical tests. Understanding the factors that influence reproductive skew is essential to understand the evolution of lekking behavior, a mating system that has evolved in a number of taxa and that has received a great deal of attention in theoretical and empirical literature. Measures of reproductive skew in lekking species are often based on observations of copulations at the lek. Yet, paternity analyses using molecular genetic data have revealed that for a number of bird species observations may provide misleading results about paternity. In the proposed study, observational data at leks are combined with direct measures of individual male success and reproductive skew through paternity analyses of offspring found at nests. This research will be the first to compare lekking behavior and its genetic consequences among a set of closely related species that occur in the same forest but that vary in lek organization and spatial structure. Such an approach should contribute substantially to our understanding of the evolution of lek mating system. The proposed research also effectively combines the ecological, behavioral, and molecular genetic expertise of the principal investigators and provides an avenue for new collaborative research that will enhance research programs of each senior investigator. Field and laboratory components of the research program will provide key opportunities for students from both the home institution and from Ecuadorean universities to gain research experience. Several Ecuadorean and UM-St. Louis students are expected to expand on aspects of the proposed project as part of their thesis or dissertation research. Travel expenses in Ecuador incurred by UM-St. Louis students and faculty will be supported by the NSF OFfice of International Science and Engineering.