The Ecology of Cooperative Breeding Taiwan Yuhinas (Yuhina brunneiceps) in Mayfeng Areas

• Main Authors: Sheng-Feng Shen, 沈聖峰
• Other Authors: Pei-Fen Lee
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/37542287845342544104

碩士 === 國立臺灣大學 === 動物學研究所 === 90 === We studied Taiwan yuhinas(Yuhina brunneiceps), the only found passerine with frequent joint-nesting behaviors, to study the male incubation hypothesis and the costs and benefits of joint-nesting behavior in the mountains of central Taiwan, from June 1999 to September 2001. Alpha females took the major incubation works in both diurnal (67%, n=27) and nocturnal (73%, n=11) incubations, which didn’t fit the male incubation hypothesis. Yuhinas inhabited in a sub-tropic fluctuating environment with high nest predation and frequent typhoons. In the aspects of fitness components, larger groups did not have higher nest success rates or more fledglings. Instead, they reduced their investment to single nest attempt by laying fewer eggs in one nest, lightening the work loads of incubation and provision in joint-nesting groups. Individuals, except alpha males, in larger groups had higher survival probabilities, especially for the females who lightened the incubation works in larger groups. Larger groups could also build nests and renest faster than solitary pairs and have better home ranges in terms of possible nests site, food and tree covers. Therefore, the joint-nesting behavior was possibly benefit from bet-hedging strategies in the fluctuating environment.