Background: Melanin?based coloration is often found to be associated with variations in physiological and behavio?ral traits that are essential in avian communication.However,the function of melanin?based traits to th...Background: Melanin?based coloration is often found to be associated with variations in physiological and behavio?ral traits that are essential in avian communication.However,the function of melanin?based traits to their bearers has been investigated less than that of carotenoid?based ones.It is commonly believed that expression of melanin?based pigmentation is genetically controlled.However,whether it could be modulated by physical condition has remained controversial.In this study,we demonstrate that the level of melanin?based plumage pigmentation could be nega?tively correlated with an individual's oxidative stress level.Methods: In this study,we used two groups of Black Bulbuls(Hypsipetes leucocephalus nigerrimus) obtained from a pet?shop in 2010 and 2011 to examine the correlation between the melanin?based plumage coloration and the ratio of lymphocytes to heterocytes,which is an indicator of the oxidative stress experienced by an individual.Results: We found a negative correlation between oxidative stress levels and expression of melanin?based pigmen?tation on the breast and scapular feathers,but the correlation only appeared in the 2011 group,individuals of which had higher oxidative stress level and brighter plumage(i.e.more melanins) than those of the 2010 group.Conclusions: Our data suggest that melanin?based plumage could reflect an individual's physical condition in certain situations.Therefore,melanin?based plumage coloration could have a function in Himalayan Black Bulbuls' communication.展开更多
To fill the gap in breeding biology information about the Red-Whiskered Bulbul （Pycnonotus jocosus）, in 2013, we studied the breeding biology of this species in Xishuangbanna, southwest China. The breeding began fro...To fill the gap in breeding biology information about the Red-Whiskered Bulbul （Pycnonotus jocosus）, in 2013, we studied the breeding biology of this species in Xishuangbanna, southwest China. The breeding began from February and continued until early August. The breeding strategy of P. jocosus was more flexible and their nests were only built in cultivated landscapes, whereas, no nest building in native tropical rain forest was found. Small open cup nests were built on 50 different plant species, and at heights ranging from 2.1±0.6 m above the ground （n=102）. The mean clutch size was 2.53±0.51 eggs （n=40） and the mean egg mass was 2.81±0.25 g （n=60）. The average incubation period was 11.1±0.5 days （n=14）, and the average nestling period was 11.0±0.8 days （n=31）. The overall nest success was 34.22%.The hatching and fledging showed either asynchrony or synchrony. Invertebrate food decreased with nestling age, whereas, plant food increased with nestling age. Moreover, distinct parental roles of the parents in nestling period were found. Compared with other passerine species, P. jocosus spent less time in incubating （58%）. The clutch size, incubation and nestling period of the P. jocosus in southwest China were different from those of the R jocosus in India.展开更多
Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows the...Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows them to identify the parasitic eggs, so that egg discrimination behavior may have evolved from nest sanitation behavior. However, whether nest sanitation behavior could improve egg rejection in cuckoo hosts was inconclusive.Methods: In this study, we investigated the relationship between nest sanitation and egg discrimination behavior in a potential cuckoo host, the Brown-breasted Bulbul(Pycnonotus xanthorrhous) with two experimental groups. In the first group, we added a blue, non-mimetic egg to the nest of the host, while in the second group we added a blue, non-mimetic egg and a peanut half-shell.Results: The results showed that in the first group, the probability of rejecting the non-mimetic eggs was 53.8%(n = 26 nests). In comparison, all of the Brown-breasted Bulbuls in the second group were able to rapidly remove the peanut shells from the nest, but only 52.6%(n = 19 nests) rejected the non-mimetic eggs. The rejection rates of the non-mimetic eggs in both experimental groups were not significantly different.Conclusions: Our study indicated that nest sanitation behavior of Brown-breasted Bulbuls did not influence their egg recognition and that egg discrimination ability of Brown-breasted Bulbuls was not directly related to nest sanitation behavior.展开更多
基金founded by the Population Genetics Lab,Department of Life Science,National Taiwan Normal University
文摘Background: Melanin?based coloration is often found to be associated with variations in physiological and behavio?ral traits that are essential in avian communication.However,the function of melanin?based traits to their bearers has been investigated less than that of carotenoid?based ones.It is commonly believed that expression of melanin?based pigmentation is genetically controlled.However,whether it could be modulated by physical condition has remained controversial.In this study,we demonstrate that the level of melanin?based plumage pigmentation could be nega?tively correlated with an individual's oxidative stress level.Methods: In this study,we used two groups of Black Bulbuls(Hypsipetes leucocephalus nigerrimus) obtained from a pet?shop in 2010 and 2011 to examine the correlation between the melanin?based plumage coloration and the ratio of lymphocytes to heterocytes,which is an indicator of the oxidative stress experienced by an individual.Results: We found a negative correlation between oxidative stress levels and expression of melanin?based pigmen?tation on the breast and scapular feathers,but the correlation only appeared in the 2011 group,individuals of which had higher oxidative stress level and brighter plumage(i.e.more melanins) than those of the 2010 group.Conclusions: Our data suggest that melanin?based plumage could reflect an individual's physical condition in certain situations.Therefore,melanin?based plumage coloration could have a function in Himalayan Black Bulbuls' communication.
基金supported by funding from the National Nature Science Foundation of China(31370452)the Chinese Academy of Science(KSCX2-EW-Q-17)
文摘To fill the gap in breeding biology information about the Red-Whiskered Bulbul （Pycnonotus jocosus）, in 2013, we studied the breeding biology of this species in Xishuangbanna, southwest China. The breeding began from February and continued until early August. The breeding strategy of P. jocosus was more flexible and their nests were only built in cultivated landscapes, whereas, no nest building in native tropical rain forest was found. Small open cup nests were built on 50 different plant species, and at heights ranging from 2.1±0.6 m above the ground （n=102）. The mean clutch size was 2.53±0.51 eggs （n=40） and the mean egg mass was 2.81±0.25 g （n=60）. The average incubation period was 11.1±0.5 days （n=14）, and the average nestling period was 11.0±0.8 days （n=31）. The overall nest success was 34.22%.The hatching and fledging showed either asynchrony or synchrony. Invertebrate food decreased with nestling age, whereas, plant food increased with nestling age. Moreover, distinct parental roles of the parents in nestling period were found. Compared with other passerine species, P. jocosus spent less time in incubating （58%）. The clutch size, incubation and nestling period of the P. jocosus in southwest China were different from those of the R jocosus in India.
基金supported by the National Natural Science Foundation of China(Nos.31672303 to CY,31472013 and 31772453 to WL)
文摘Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows them to identify the parasitic eggs, so that egg discrimination behavior may have evolved from nest sanitation behavior. However, whether nest sanitation behavior could improve egg rejection in cuckoo hosts was inconclusive.Methods: In this study, we investigated the relationship between nest sanitation and egg discrimination behavior in a potential cuckoo host, the Brown-breasted Bulbul(Pycnonotus xanthorrhous) with two experimental groups. In the first group, we added a blue, non-mimetic egg to the nest of the host, while in the second group we added a blue, non-mimetic egg and a peanut half-shell.Results: The results showed that in the first group, the probability of rejecting the non-mimetic eggs was 53.8%(n = 26 nests). In comparison, all of the Brown-breasted Bulbuls in the second group were able to rapidly remove the peanut shells from the nest, but only 52.6%(n = 19 nests) rejected the non-mimetic eggs. The rejection rates of the non-mimetic eggs in both experimental groups were not significantly different.Conclusions: Our study indicated that nest sanitation behavior of Brown-breasted Bulbuls did not influence their egg recognition and that egg discrimination ability of Brown-breasted Bulbuls was not directly related to nest sanitation behavior.
