同域分布下丝光椋鸟与灰椋鸟的繁殖行为

2011年3—6月,通过悬挂巢箱人工招引丝光椋鸟(Sturnus sericeus)及同域分布下的灰椋鸟(Sturnus cineraceus),并对其繁殖生态进行了初步研究。共设置椋鸟式巢箱40个,其中椋鸟的入住率是84.6%,营巢成功率是51.5%,利用摄像机对其中3巢丝光椋鸟与3巢灰椋鸟进行了系统的繁殖行为观察。结果显示:丝光椋鸟窝卵数为6～7枚,灰椋鸟窝卵数5～7枚,后者的卵显著大于前者;丝光椋鸟的育雏期(20d)较灰椋鸟(16d)长,且亲鸟的递食率明显较高;育雏期丝光椋鸟亲鸟的警戒频次也明显高于灰椋鸟。因此,相比于灰椋鸟,丝光椋鸟具有更完善的育雏行为机制。另外,本文还首次报道了丝光椋鸟的种内巢寄生现象。

Breeding behavior of sympatric silky starlings and white-cheeked starlings

Silky starling (Sturnus sericeus) is endemic in East Asia, but little is known about its breeding behavior. From March to June 2011, an experiment with artificial nest box was conducted to study the breeding ecology of silky starlings and that of sympatric white-cheeked starlings (S. cineraceus) at the old and new campus of Nanjing University. A total of 40 nest boxes were installed, of which, 33 boxes (84.6%) were occupied by the starlings, and 17 broods (51.5%) were successfully hatched. We videotaped the reproductive behavior at three nests of silky starlings and three nests of white-cheeked starlings. The clutch size of silky starlings ranged from 6 to 7 eggs while that of white-cheeked starlings varied from 5 to 7 eggs, and the eggs of white-cheeked starlings were significantly larger than those of silky starlings. Silky starlings had a longer nestling period than white-cheeked starlings (with a mean of 20 days vs. 16 days), and also, an obviously higher feeding rate. Compared with white-cheeked starlings, silky starlings were more vigilant and aggressive during their nestling period, and thus, could have more constructive parental care mechanism than white-cheeked starlings. In addition, this paper first reported the occurrence of silky starlings intraspecific nest parasitism.