Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada.
Biol Lett. 2011 Oct 23;7(5):661-3. doi: 10.1098/rsbl.2011.0115. Epub 2011 Apr 6.
Facultative, partially migratory animals provide a contemporary window into the evolution of migration, offering rare opportunities to examine the life-history trade-offs associated with migration. For the first time, to our knowledge, we describe the nature of these trade-offs, using a lek-breeding tropical bird, the white-ruffed manakin (Corapipo altera). Previous evidence indicated that weather drives post-breeding migration to lower elevations bringing condition-related benefits. Using elevation-sensitive stable isotope measurements and more than 1200 h of behavioural observations, we show that male manakins which migrate incur costs of diminished social status and matings with females the following breeding season. Because migratory tendency depends on inter-annual variation in weather, physical costs of displays and breeding prospects the following year, migratory decisions are subject to both natural and sexual selection, with the outcome of such decisions linked to changing climatic regimes.
兼性、部分迁徙动物为我们了解迁徙的进化提供了一个当代窗口，为研究与迁徙相关的生活史权衡提供了难得的机会。据我们所知，这是我们第一次使用热带领地繁殖的白颈蓝须雀（Corapipo altera）来描述这些权衡的本质。先前的证据表明，天气会促使繁殖后的鸟类迁徙到较低海拔地区，从而带来与健康相关的好处。利用对海拔敏感的稳定同位素测量和超过 1200 小时的行为观察，我们发现迁徙的雄雀会付出社会地位下降和在下一个繁殖季节与雌雀交配的代价。由于迁徙倾向取决于天气的年际变化、次年展示和繁殖的身体成本，因此迁徙决策受到自然选择和性选择的影响，而这些决策的结果与不断变化的气候模式有关。
