Prévot-Julliard Anne-Caroline, Pradel Roger, Julliard Romain, Grosbois Vladimir, Lebreton Jean-Dominique
CEFE-CNRS, 1919 route de Mende, 34293, Montpellier Cedex 5, France.
CRBPO-Museum National d'Histoire Naturelle, 55 rue Buffon, 75005, Paris, France.
Oecologia. 2001 Mar;127(1):62-68. doi: 10.1007/s004420000564. Epub 2017 Apr 22.
In long-lived colonial birds, age at recruitment is an important life-history character. Variation in this parameter may reflect differences in several factors, including competitive ability and breeding strategies. Further, these differences may be due to timing of hatching (for instance through differences in competitive ability). We investigated the age of first-time breeders in relation to hatching date in a black-headed gull Larus ridibundus colony situated in central France, from 1979 to 1993. Age at first breeding was estimated for four groups of individuals (total n=550) according to their hatching date, using a recent capture-recapture methodology which allowed us to estimate recruitment rate without the limiting assumptions of methods relying on simple return rates. The age at first breeding was negatively correlated with the hatching date of individuals: individuals hatched earlier in the season started breeding at a younger age than individuals born later. Proportionally more 2-year-old late-hatched individuals were seen breeding on small peripheral colonies than young early-hatched individuals. This difference disappeared after age 3 years. These results strongly suggest that individuals hatched late in the season start to breed on peripheral colonies before recruiting to their natal colony. A difference of few weeks in hatching date has consequences which can last for several years.
在寿命较长的群居鸟类中，首次繁殖的年龄是一个重要的生活史特征。该参数的变化可能反映了几个因素的差异，包括竞争能力和繁殖策略。此外，这些差异可能归因于孵化时间（例如通过竞争能力的差异）。我们研究了1979年至1993年位于法国中部的一个黑头鸥（Larus ridibundus）种群中首次繁殖者的年龄与孵化日期的关系。根据孵化日期，使用一种最新的标记重捕方法，对四组个体（总数n = 550）的首次繁殖年龄进行了估计，该方法使我们能够在不依赖于简单回捕率方法的有限假设的情况下估计补充率。首次繁殖的年龄与个体的孵化日期呈负相关：在季节中较早孵化的个体比晚出生的个体开始繁殖的年龄更小。在小型边缘种群中，比例上更多的2岁晚孵化个体比早孵化的年轻个体繁殖。3岁以后这种差异消失。这些结果有力地表明，在季节后期孵化的个体在加入其出生种群之前先在边缘种群开始繁殖。孵化日期相差几周会产生持续数年的后果。
