Cases of nest usurpation in Japanese Tits (Parus minor) with mixed brood

This study was done at three sites. Saihanba National Forest Park (SHB, 116°92' E, 42°20' N) is located in the northernmost part of Hebei Province, China. It is the main natural secondary forest and artificial forest area in Hebei (Liu et al. 2017). Xiaolongmen National Forest Park (XLM, 115°25' E, 39°57' N) is about 110 km from the urban area of Beijing, and its vegetation is mainly composed of secondary temperate deciduous broad-leaved forests (Liang et al. 2016). Diaoluoshan National Forest Park (DLS, 109°54' E, 18°40' N) is about 20 km from Lingshui county, Hainan Island. The study area mainly planted Areca catechu, with secondary broadleaf forest and scrub (Liang et al. 2016).We reported five cases of nest usurpation related to Japanese Tits (Parus minor): 1) Willow Tits (Poecile montanus) usurped a Japanese Tit nest, 2) Japanese Tits usurped the nests of Oriental Magpie Robins (Copsychus saularis), 3) Willow Tits, 4) Coal Tits (Periparus ater), and 5) Coal Tits usurped a Japanese Tit nest. In three of the five cases, mixed brood were successfully fledged. Our results and discussion suggest several cases of successful mixed brood have been observed in nest usurpation events associated with Paridae.