Sexual dimorphism, dispersal patterns, and breeding biology of the Taiwan Yuhina: a joint-nesting passerine

摘要

We studied the breeding ecology of Taiwan Yuhinas (Yuhina brunneiceps) at the Highlands Experiment Farm at Meifeng, National Taiwan University, in 1995 and from 1997-2002. The Taiwan Yuhina is a joint-nesting, cooperatively breeding species endemic to Taiwan. Males had significantly longer wing chords and tail lengths than females, probably due to sexual selection. Males also had a longer residence time at Meifeng than their female mates, which could be explained by philopatry being greater in males. Alpha males had a significantly longer residence time at Meifeng than beta males, but this was not the case for females, because females did not remain in the same group as males did after their mates disappeared. The breeding season was approximately 6 months long and multiple brooding was common. Nest building took 3 days, egg laying occurred over 3-4 days, the average incubation period was 14 days, and the nestling period was 12 days. Breeding success did not decrease later in the breeding season. Maximum longevity was 12 years, and the estimate of average annual overwinter survival rate for adults at Meifeng was 74%.