LTREB Renewal: Long-term Investigation of Territorial Behavior and Population Dynamics in the Common Loon

这个长期项目的重点是普通的潜鸟，这种潜水鸟在美国北部的湖泊上繁殖，以其响亮的、类似人类的叫声而闻名。雄性和雌性都保护自己的领地不受入侵者的侵犯，入侵者通常会用武力夺取它们。大约三分之一的雄性接管对被取代的繁殖者来说是致命的；雌性很少搏斗至死。目前的理论预测，在短命的动物中，致命的战斗应该是频繁的，因为它们很少有繁殖的机会，但像飞禽这样的生物不应该战斗到死，因为它们寿命长，领土丰富。在十年的时间里，该项目正在测试三种假设来解释致命的战斗：1)致命的战斗是年老的、衰落的雄性的“终极投资”；2)战斗到死的雄性会很好地保护雏鸟，这抵消了它们的过度攻击性；3)对领地的极度熟悉会导致致命的战斗。为了验证这些假设，研究人员跟踪并观察了大量被标记的个体，测量了捕获的潜鸟的体重，并分析了一段时间内的领土斗争、篡夺和生存模式。这项研究的结果将帮助科学家了解动物的致命竞争、攻击性行为和衰老过程。虽然潜鸟在它们的活动范围内很常见，但它们被威斯康星州自然资源部认为是特别值得关注的，并且在它们的活动范围内正在减少。该项目的长期数据和结果将为保护和管理计划提供信息。此外，该项目将培养一大批本科生，他们将通过开展独立的实地项目，学习实验设计、数据收集和统计分析。关于这种受欢迎的鸟类的发现将通过流行文章、电视、广播采访和项目网站与更广泛的公众分享。

This long-term project focuses on common loons, diving birds that breed on lakes in the northern U.S. and are famous for their loud, humanlike vocalizations. Both sexes defend territories from intruders, which often take them by force. About one-third of all male takeovers are fatal for the displaced breeder; females seldom fight to the death. Current theory predicts that lethal battles should be frequent in short lived animals because they have few reproductive opportunities, but organisms such as loons should never fight to the death because they are long-lived and territories are plentiful. Over the course of ten years, the project is testing three hypotheses to account for fatal fighting: 1) fatal battles constitute a 'terminal investment' for old, declining males, 2) males that fight to the death defend chicks well, which offsets their hyper-aggressiveness, and 3) extreme familiarity with a territory causes fatal battles. To test these hypotheses, the researchers follow and observe a large number of marked individuals, measure body mass of captured loons, and analyze territorial fights, usurpations and survival patterns across time. Results from this study will help scientists understand lethal contests in animals, aggressive behavior, and the process of aging. Though loons are common within their range, they are considered of special concern by the Wisconsin Department of Natural Resources, and are declining across their range. Long-term data and results from this project will inform conservation and management programs. In addition, the project will train a large number of undergraduate students who, by initiating independent field projects, will learn about experimental design, data collection and statistical analysis. Discoveries about this popular bird will be shared with the broader public via popular articles, T.V. and radio interviews, and a project website.