US-Sweden Cooperative Science: Origin of Polygyny in a Polyterritorial System

该奖项将支持匹兹堡大学William Searcy博士和瑞典乌普萨拉大学动物学系Arne Lundberg博士在鸟类行为生态学方面的合作研究。提出的研究目的是收集和分析对多领地和一夫多妻制斑蝇进行充分研究的关键现场数据。研究者建议研究这种物种的一夫多妻制的适应性基础，其中一夫多妻制与单个雄性对多个领土的防御密切相关（多领地性）。如果雌性斑姬鹟选择已经交配的雄性，就会付出健康成本，而这种成本并不能通过获得更好的领地或配偶来补偿。目前有一种假说认为，为什么雌性仍然会选择一夫多妻制，那就是多领地制允许雄性在交配状态上欺骗雌性。第二种假设是，尽管知道雄性的真实交配状态，雌性还是选择了交配的雄性，因为继续寻找一个未交配的雄性的成本很高。研究人员计划通过确定在未交配的雌性观察期间，交配和未交配的雄性之间的行为是否存在可靠的差异来验证第一个假设。如果存在这种差异，女性应该能够决定男性的交配地位。第二个假设将通过确定最终与雄性交配的雌性是否以前遇到过未交配的雄性来验证。这两项测试都将通过跟踪单独标记的雌性的配偶寻找来进行，这些雌性被迫通过移除它们以前的配偶和巢箱来寻找新的伴侣。该项目将受益于Searcy博士和Lundberg博士对该物种的有效实地工作记录的综合实验专业知识。本研究的成果将对行为生态学领域做出重要贡献。

This award will support collaborative research in avian behavioral ecology between Dr. William Searcy, University of Pittsburgh and Dr. Arne Lundberg, Department of Zoology, Uppsala University, Sweden. The objective of the proposed research is the collection and analysis of critical field data on the well-studied polyterritorial and polygynous pied flycatcher. The investigators propose to examine the adaptive basis of polygyny in this species, in which polygyny is closely associated with the defense of multiple territories by single males (polyterritoriality). Female pied flycatchers pay a fitness cost if they choose an already-mated male, and they are not compensated for this cost by receiving a better territory or mate. One current hypothesis on why females nevertheless do mate polygynously is that the polyterritorial system allows males to deceive females about their mating status. A second hypothesis is that females choose mated males despite being aware of the male's true mating status, because of the high cost of continuing to search for an unmated male. The investigators plan to test the first hypothesis by determining whether there are reliable differences in behavior between mated and unmated males during periods when unmated females are observing them. If such differences exist, females ought to be able to determine male mating status. The second hypothesis will be tested by determining whether females that ultimately settle with mated males have previously encountered unmated males. Both tests will be performed by following the mate search of individually marked females forced to search for new mates by the removal of their previous mate and nestbox. The project will benefit from the combined experimental expertise of Dr. Searcy and Dr. Lundberg's record of productive field work with this species. The results of this research will make an important contribution to the field of behavioral ecology.