The Breeding Ecology Of Red Whiskered Bulbul(Pycnonotus Jocosus) In Xishuangbanna

Red-Whiskered Bulbul(Pycnonotus jocosus) has a significant function for ecosystem as a common seed disperser in Asia. But there are many vacancies in breeding ecology. In 2013, we studied the breeding ecology of P.jocosus in Xishuangbanna through field survey(control group), exchanging the nestlings between different broods(cross-fostering group) and the video recording technology. The purpose and results of our research are below:(1) The breeding biology of P.jocosus: Breeding began in the end of February and continued until early August. Small open cup nests were built on 50 different plant species, mean clutch size was 2.53 ± 0.51 eggs. Egg mass was 2.81 ± 0.25 g. Average incubation period was 11.07 ± 0.47 days, and average nestling period was 10.97 ± 0.80 days. Both of hatching and fledging may have two patterns(asynchrony or synchrony). The growth rate constant(k) for mass was 0.45; the asymptote(A) was 18.10 g. The parents have parental roles in nestling period. Overall nest success was 34.22%. In Xishuangbanna, P. jocosus has a smaller clutch size, a shorter incubation and nestling period than other regions, which suggested that P. jocosus can adapt its breeding biology to different environmental conditions.(2) The egg mass of P.jocosus increased with laying order, in the broods clutch size 3 the egg mass of laying order 3 was significant higher than laying order 1. The laying order was a predictor of hatching order in asynchrony broods. The egg mass of hatching order 2 was significant higher than hatching order 1.(3) Our results supported parents manipulation hypothesis in nestlings fledging: a) the parents control food distribution: In nature group and cross-fostering group, food distribution has no significant difference in synchronous fledging broods, but the frequency of senior was significant higher than junior in asynchronous fledging broods. b) Feeding frequency in the fledging day was significant lower than the day before; the parents may decrease feeding frequency to increase starving intensity of nestlings to stimulate the nestlings fledging. c) The parents have allure behavior by flying through nest with food in mouth but without feeding. We predicted that the parents could adjust the nestling growth through food distribution, and decrease feeding frequency and lure them by food to stimulate the nestlings fledging, which showed that they can control nestlings fledging.(4) In nature group, the factors influenced food intake of a nestling was age, begging intensity, and nestling mass, the nestling mass was the most important one. In cross fostering group, the begging intensity and begging time of junior was significant higher than the senior, but the food allocation rate of junior was reverse.(5) The individual feeding frequency in brood size 1 was significant higher than the nestlings in brood size 2 and 3, but the begging intensity and begging time of nestling in brood size 1 was significant higher than in the others, which predicted that the begging behavior play a role in stimulating parents to provide food for the brood; the begging intensity and begging time of nestlings in brood size 3 was higher than brood size 2. It seemed that the begging behavior has an effect on food competition. The nestlings may adjust begging behavior under the assumption of revenue maximum.In conclusion, the P. jocosus has a special mechanism in egg laying and incubation stage. The parents can control food distribution and nestlings fledging to adjust the breeding strategy with environment change, which supports the brood reduction hypothesis. However, further research is needed to make the predictions and conclusions since our sample size was not enough.