塞罕坝林区大杜鹃在黑喉石(即鸟)巢中寄生观察

Nest Parasitism on Siberian Stonechat by Common Cuckoo in Saihanba Forest Region

2012～2015年,在河北省塞罕坝机械林场发现9巢黑喉石被大杜鹃寄生,巢寄生率23.08%。发现的大杜鹃的卵色、卵形一致,卵淡灰褐色,其上被有深褐色斑点,形似溅落的墨迹,多集中在钝端,大小平均23.18 mm×17.38 mm,重量平均3.83 g,卵孵化期13 d,雏鸟在巢期19 d。黑喉石卵灰绿色(近鸭蛋青色),其上被有橙褐色斑和淡褐色细纹,橙褐色斑多集中在钝端,卵大小平均17.48 mm×13.80 mm,重量平均1.81g。大杜鹃卵与黑喉石卵的差别明显,均被黑喉石接受。

From 2012 to 2015,we found nine nests of Siberian stonechat(Saxicola torquata)that were parasitized by common cuckoo(Cuculus canorus)in Hebei Province,Saihanba Machinery Forest Farm.The nest parasitism rate was 23%.The color and shape of common cuckoo eggs were consistent.The eggs were grey brown,with many dark brown speckles resembling splashes of ink,most of which were near the blunt end of the egg.The average size was 23.2 mm×17.4 mm,the average egg weight was 3.83 g.The hatching period of the eggs was 13 days,the nestlings remained in the nest for 19 days.Siberian Stonechat eggs were greyish green(similar to the cyan of duck eggs),there were many orange and brown speckles and light brown fine lines on the shell surface,the orange and brown speckles were mainly at the blunt end of the egg.Average egg size was 17.5 mm×13.8 mm and average egg weight was 1.8 g.The difference between common cuckoo eggs and siberian stonechat eggs was obvious,but all eggs were incubated by siberian stonechat.