贵州宽阔水自然保护区小杜鹃对小鳞胸鹪鹛的巢寄生

Brood Parasitism on Pnoepyga pusilla by Cuculus poliocephalus in Kuankuoshui Nature Reserve,Guizhou,China

2015年4—8月,在贵州宽阔水国家级自然保护区记录到小杜鹃Cuculus poliocephalus在小鳞胸鹪鹛Pnoepyga pusilla巢中寄生繁殖。发现时小鳞胸鹪鹛已处于孵卵后期,巢内有1枚红棕色的小杜鹃寄生卵和3枚小鳞胸鹪鹛的白色卵。小杜鹃卵质量为2.55 g,体积2.72 cm^3,小鳞胸鹪鹛卵质量(1.64±0.16)g(n=7),体积(1.65±0.08)cm^3(n=7),两者的卵在颜色和大小上差别明显。光纤光谱仪对卵色的测量和分析结果表明,小鳞胸鹪鹛的卵色亮度显著高于小杜鹃,小杜鹃的卵为高度非模拟寄生卵。这是小鳞胸鹪鹛被小杜鹃寄生的第二例报道,说明其可能是小杜鹃的适宜寄主。

During the breeding season from April to August 2015,one case of brood parasitism on pygmy wren babbler（ Pnoepyga pusilla） by lesser cuckoo（ Cuculus poliocephalus） was observed in Kuankuoshui National Nature Reserve,Guizhou,southwestern China. The parasitized nest with one chocolate cuckoo egg and three white babbler host eggs were found at the late incubation period. The cuckoo egg mass was 2. 55 g and egg volume was 2. 72 cm^3,while the babblers＇ egg mass was 1. 64 g ± 0. 16 g and egg volume was 1. 65 cm^3± 0. 08 cm^3（ n = 7）. Egg reflectance analysis showed that egg hue and chroma of the pygmy wren babbler were significantly different with those of lesser cuckoo,and therefore lesser cuckoo will lay a highly non-mimetic egg in its babbler host＇s nest. This was the second report of interspecific brood parasitism on pygmy wren babbler by lesser cuckoo,and suggested that pygmy wren babbler may be one of the suitable hosts for lesser cuckoo.