Demography and Fragmentation in an Avian Species: A Genetic Analysis

这个项目调查了在一个稀有和消失的栖息地中成为一名极端生态专家的遗传后果。佛罗里达灌丛鸦是一种受联邦政府威胁的鸟类，其栖息地正迅速被人类消灭。对一个有标记的种群进行了22年的详细研究表明，这些松鸦有一种不同寻常的社会制度，它们很少离开它们孵化的地方。这种非常有限的扩散可能导致基因变化在短距离内迅速发展，特别是在高度分散的栖息地。各种复杂的遗传技术（DNA“指纹”和测序）将被用于在地方和区域尺度上检查遗传变异。具体目标是：1)确认生殖只在每个领地上由配偶进行（即，很少或没有额外的配偶或域外受精）；2)检验近交水平是否影响终生生殖性能；3)比较距离、生境隔离程度和种群规模对遗传变异和分化的影响；4)检验这些遗传效应是否与长期人口统计数据预测的结果相符。除了理论应用外，本研究还将通过生境丧失和破碎化如何影响生态特化物种的基因组成，进一步保护生物多样性。

This project investigates the genetic consequences of being an extreme ecological specialist in a rare and vanishing habitat. The Florida Scrub Jay is a federally Threatened bird species, restricted to a habitat that is rapidly being eliminated by man. Twenty-two years of detailed study of a marked population have shown that these jays have an unusual social system, and rarely move more than a few territories from where they were hatched. This very limited dispersal may result in rapid development of genetic changes over short distances, especially within a habitat that is highly fragmented. A variety of sophisticated genetic techniques (DNA 'fingerprinting' and sequencing) will be used to examine genetic variation at both local and regional scales. Specific goals are to: 1) confirm that reproduction takes place only by the mated pair on each territory (i.e., extra-pair or extra-territorial fertilizations are rare or absent); 2) test whether levels of inbreeding affect lifetime reproductive performance; 3) compare the effects of distance, degree of habitat isolation, and population size on genetic variation and differentiation, and 4) test whether these genetic effects match those predicted by long-term demographic data. Besides its theoretical applications, this study will further the protection of biodiversity by showing how habitat loss and fragmentation affect the genetic makeup of ecologically specialized species.