Nest Usurpation between Mandarin Duck Aix galericulata and Coexisting Bird Species in Nest Boxes in a Secondary Forest, Zuojia Nature Reserve, China
Ye Gong, Nehafta Bibi and Haitao Wang*
While using artificial nest boxes to protect Mandarin duck Aix galericulata in a secondary forest in Northeast China, we found mixed clutches that contained eggs of Mandarin duck and other species over 11 breeding seasons (2004 - 2014). We monitored the frequency of occurrence and the fate of eggs in those nests and recorded fourteen cases of mixed clutches that contained Mandarin duck eggs. Nine cases were classified as successful nest usurpation: in six cases nests of other birds were usurped by Mandarin duck and in three cases nests of Mandarin duck were usurped by other birds. The remaining mixed clutches may be incomplete usurpation. For the nests taken over by Mandarin ducks, all heterospecific eggs were rejected and four clutches were incubated successfully. For the other mixed clutches, none of Mandarin duck eggs were removed, only two eggs were hatched but the ducklings did not survive. Nest usurpation may interfere with normal breeding activities and lead to a reduced breeding success in Mandarin duck and other coexisting bird species, which should be taken into account when providing nest boxes to protect the local population.