Eco-Ethology Research Unit, ISPA, Lisboa, Portugal.
Ecology. 2013 Jun;94(6):1230-5. doi: 10.1890/12-2177.1.
Carry-over effects relate to events or processes that influence individual performance in a subsequent season, but their occurrence in the annual cycle of migratory avian taxa is seldom studied. We investigated if different levels of resource allocation to reproduction may result in carry-over effects that change the timing and destination of long-distance migration. We reduced the parental investment of Cory's Shearwaters Calonectris diomedea by removing their chick at an early stage. When compared to individuals with greater parental investment (controls that raised chicks to close to fledging), manipulated birds started most stages of migration sooner and returned to the colony earlier at the start of the following breeding season. Late arrival in the subsequent nesting season increased the probability of skipping a breeding year. Manipulated males were less likely to engage in long-distance migration, which supports the idea that partial migration is condition dependent. Our study demonstrates experimentally that energetic or time-dependent costs of reproduction may have an enduring impact on migration schedule and on nonbreeding geographical distribution of long-distance migrants, which may also influence the ability to breed in the following season.
延续效应是指影响个体在后一个季节表现的事件或过程，但它们在候鸟年度周期中的发生频率很少被研究。我们调查了不同层次的资源分配对繁殖的影响，这些影响是否会导致延续效应，从而改变长距离迁徙的时间和目的地。我们通过在早期阶段移走雏鸟，减少了白玄鸥（Cory's Shearwater）亲鸟的繁殖投资。与投资较大的个体（将雏鸟抚养到接近离巢的对照组）相比，操纵组的鸟类更早地开始了大多数迁徙阶段，并在下一个繁殖季节开始时更早地返回了群体。在随后的繁殖季节晚到增加了跳过繁殖年份的可能性。操纵组的雄性不太可能进行长距离迁徙，这支持了部分迁徙取决于条件的观点。我们的研究通过实验证明，繁殖的能量或时间依赖性成本可能对迁徙计划和长距离候鸟的非繁殖地理分布产生持久影响，这也可能影响它们在下一个季节繁殖的能力。
