八声杜鹃在两种缝叶莺巢中寄生繁殖

了解杜鹃对不同寄主的选择和利用,可为研究两者之间的协同进化提供重要基础资料。2012至2014年每年的3~6月,在广西弄岗地区共记录到3例八声杜鹃(Cacomantis merulinus)的寄生繁殖,其中,2例寄生于栗头缝叶莺(Orthotomus cuculatus)的巢(寄生率1.4%,n=142),其中2枚杜鹃卵均为白色具棕色斑点;1例寄生于黑喉缝叶莺(O.atrogularis)(寄生率10%,n=10),杜鹃卵为白色具棕色斑点。栗头缝叶莺为八声杜鹃寄主的首次报道,而两种缝叶莺均首次在中国记录到被八声杜鹃寄生。八声杜鹃的卵重为(1.45±0.09)g,卵体积为(1.46±0.07 cm3)(n=3),其卵大小和重量均显著大于栗头缝叶莺和黑喉缝叶莺的卵(t检验,P0.001)。

Brood Parasitism on Two Tailorbird Hosts (Orthotomus spp.) by Plaintive Cuckoo (Cacomantis merulinus)

During the breeding season from March to July in 2012-2014, two nests (1.4% of parasitism rate, n=142) of the Mountain Tailorbird (Orthotomus cuculatus) and one nest (10%, n=10) of the Dark-necked Tailorbird (O. atrogularis) were found to be parasitized by the Plaintive Cuckoo (Cacomantis merulinus) in Nonggang area, Guangxi, Southwestern China. The Mountain Tailorbird was firstly recorded as host species by Plaintive Cuckoo, and both the two tailorbird species were firstly recorded as Plaintive Cuckoo hosts in China. The egg mass and volume of the Plaintive Cuckoo were significantly larger than those of the two tailorbird hosts. Spectra analysis of egg reflectance showed that both background color and spot markings of the cuckoo eggs were much different from its two tailorbird hosts.