Abstract: 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.

Key words: aquatic organism, oxidative stress, hexavalent chromium, antioxidant system.