Shorebird life histories at multiple levels of analysis

生物体有多种生存和繁殖的方式和时间表，称为“生活史策略”。 这项研究解决了小滨鸟物种之间的生活史策略的差异，也在物种内的个人。 当性状对生物体的生存或繁殖成功有很大影响时，种群生物学家就面临着解释为什么这些性状的遗传变异会持续存在的挑战。 这项研究探索了允许这些特征的竞争形式共存的机制。 我的工作主要是在繁殖行为和鹬，小滨鸟迁移行为的差异。 大多数关于繁殖行为的研究都涉及到一种奇特的旧大陆鹬，（Philomachus pugnax），其中三种不同类型的男性在繁殖季节发生：（1）为交配场所而斗争的领土雄性，（2）不斗争的“卫星”雄性，而是被招募加入他们的场所中的正常领土雄性，和（3）罕见的“女性模仿”雄性，它们既不飞行也不向雌性炫耀，但仍然会交配。 我们正在研究这三种雄性如何在种群中维持自己，它们如何与雌性交配，行为如何受到生殖调控，以及类型之间存在哪些遗传差异。 对相关滨鸟物种的研究提出了一个问题，即为什么一些雌性在一次繁殖尝试中会与几个不同的雄性交配。 我们正在测试雌性如何从拥有更多基因多样性的后代中获益的理论。 在最后一个物种，西方鹬，我们正在确定迁移距离如何影响未来的生存和繁殖率。 看来，迁徙距离较远的鸟类比迁徙距离较短的鸟类有更高的生存率，但繁殖频率较低，这代表了“生活史权衡”。 了解不同的生命史如何持续，有助于我们预测物种在面对环境变化时的适应能力。

Organisms have diverse ways and schedules to survive and reproduce, referred to as their "life history strategies". This research addresses differences in life history strategies between species of small shorebirds, and also among individuals within species. When characters have strong effects on an organism's survival or reproductive success, population biologists are challenged to explain why genetic variation for such characters persists. This research explores mechanisms that permit coexistence of competing forms of such traits. I work primarily with differences in reproductive behaviour and migration behaviour of sandpipers, small shorebirds. Most of the research on reproductive behaviour involves a peculiar old-world sandpiper, the Ruff (Philomachus pugnax), in which three distinct types of males occur during the breeding season: (1) territorial males that fight for mating courts, (2) "satellite" males that do not fight, but are instead recruited to join with the normally territorial males on their courts, and (3) rare "female mimic" males, which neither flight nor display to females, but nonetheless do mate. We are studying how these three kinds of males maintain themselves in populations, how they obtain matings with females, how behaviour is regulated hormonally, and what genetic differences exist among types. Studies with related shorebird species ask why some females mate with several different males during a single breeding attempt. We are testing theories about how females may gain from having more genetically diverse offspring. In a final species, the Western Sandpiper, we are determining how migration distance affects future survivorship and reproductive rates. It appears that birds that migrate farther have higher survivorship, but breed less often, than those with shorter migrations, which would represent a "life history tradeoff". Understanding how different life histories persist helps us predict how adaptable species will be in the face of environmental changes.