LTREB: Linking Individual and Spatial Variation to Demography and Population Dynamics of a Neotropical Parrotlet

LTREB：将个体和空间变化与新热带鹦鹉的人口统计学和种群动态联系起来这个长期的研究项目将继续对南美鹦鹉绿背鹦鹉（Forpus passerinus）进行研究，以解决个体之间和小距离内行为、人口统计学和种群动态的显著差异。自1988年以来在委内瑞拉继续进行的长期研究将把社会制度、人口分散和人口统计同人口动态联系起来。13年的类似工作揭示了一个复杂的社会系统，在不同的社会群体中，大量的非繁殖雄性占主导地位，低率的额外交配受精通常分配给远离筑巢对的雄性，两个种群（高地和低地）之间的交配开始的空间差异不寻常，距离仅500米，海拔相差1-2米。他们还发现，这两个种群的人口增长模式不同，这可以归因于：(1)高地种群的繁殖成功率更高；(2)年轻雌性比雄性分散得更远，经常完全离开研究区域；(3)年轻雄性从质量较差的低地栖息地分散到质量较好的高地栖息地。该研究的具体目标是：(1)确定繁殖者和非繁殖者的运动模式和从属关系，以及幼崽的分散，以了解它们如何解释额外的配对亲代模式、繁殖开始时的小规模变化以及性别和种群之间的差异；(2)记录在小空间尺度上的鹦鹉种群繁殖开始的年变化，并测量食物的可获得性，以了解这对产卵时间的影响；(3)通过建立将人口行为与性别和生境相关的人口差异相结合的人口模型，了解人口个体和空间差异对人口动态的影响。研究目标将通过扩大所研究的鹦鹉种群数量来实现；利用无线电遥测技术跟踪正在繁殖的雄性和非繁殖的雄性的日常活动和相互作用；继续进行行为，人口统计和环境监测，以完善我们对社会系统的理解，并估计死亡率。

LTREB: Linking Individual and Spatial Variation to Demography and Population Dynamics of a Neotropical ParrotSteven R. BeissingerThis long-term research project will continue studies of a South American parrot, the Green-rumped Parrotlet (Forpus passerinus), to address marked variation among individuals and across small distances in behavior, demography and population dynamics. Continued long-term studies, which have been conducted since in Venezuela since 1988, will link social system, dispersal and demography to population dynamics. Thirteen years of similar work has revealed a complex social system dominated by large numbers of nonbreeding males which occur in various social groupings, a low rate extra-pair fertilizations that are often assigned to males residing far from the nesting pair, and unusual spatial variation in the onset of breeding between two populations (upland and lowland) located only 500 m apart and differing in elevation by 1-2 meters. They have also found different patterns of population growth in the two populations that can be attributed to: (1) higher reproductive success in the upland population, (2) young females dispersing much farther than males, often leaving the study area altogether, and (3) young males dispersing from the poorer quality lowland habitat to the better quality upland habitat.Specific objectives of the study are to: (1) determine movement patterns and affiliations of breeders and nonbreeders, and dispersal of young to understand how they might account for extra-pair parentage patterns, small-scale variation in the onset of breeding, and differences among the sexes and populations; (2) document annual variation in the onset of breeding among populations of parrotlets that occurs at small spatial scales and measure food availability to see how this affects timing of laying; and (3) understand the effects of the individual and spatial differences in demography and population dynamics by developing population models that integrate behavior with sexual- and habitat-related differences in demography. Study goals will be accomplished by expanding the number of parrotlet populations under study; using radio-telemetry to track the daily movements and interactions of breeding pairs and nonbreeding males; and continuing behavioral, demographic and environmental monitoring to refine our understanding of the social system and to estimate vital rates.