Chinese bulbuls （Pycnonotus sinensis） are small passerine birds that inhabit areas of central, southern and eastern China. Previous observations suggest that flee-living individuals of this species may change their ...Chinese bulbuls （Pycnonotus sinensis） are small passerine birds that inhabit areas of central, southern and eastern China. Previous observations suggest that flee-living individuals of this species may change their food intake in response to seasonal changes in ambient temperature. In the present study, we randomly assigned Chinese bulbuls to either a 30 ~C or 10 ~C group, and measured their body mass （BM）, body temperature, gross energy intake （GEl）, digestible energy intake （DEI）, and the length and mass of their digestive tracts over 28 days of acclimation at these temperatures. As predicted, birds in the 30 ℃ group had lower body mass, GEI and DEI relative to those in the 10 ℃ group. The length and mass of the digestive tract was also lower in the 30 ℃ group and trends in these parameters were positively correlated with BM, GEl and DEI. These results suggest that Chinese bulbuls reduced their absolute energy demands at relatively high temperatures by decreasing their body mass, GEI and DEI, and digestive tract size.展开更多
Food resources play an important role in the regulation of animals’ physiology and behavior. We investigated the effect of short-term food restriction on metabolic thermogenesis of Chinese bulbuls（Pycnonotus sinensi...Food resources play an important role in the regulation of animals’ physiology and behavior. We investigated the effect of short-term food restriction on metabolic thermogenesis of Chinese bulbuls（Pycnonotus sinensis） by measuring changes in body mass, body fat, basic metabolic rate（BMR）, and organ mass of wild-caught Chinese bulbuls from Wenzhou, China. Short-term food restriction induced a significant decrease in body mass and body fat but body mass returned to normal levels soon after food was no longer restricted. Food restriction caused a significant reduction in BMR after 7 days（P〈0.05）, which returned to normal levels after food restriction ceased. Log total BMR was positively correlated with log body mass（r2=0.126, P〈0.05）. The dry masses of livers and the digestive tract were higher in birds that had been subject to temporary food restriction than in control birds and those subject to continual food restriction（P〈0.001 and P〈0.05, respectively）. There was also significant differences in the dry mass of the lungs（P〈0.05）, heart（P〈0.01）, and spleen（P〈0.05） in birds subject to short-term food restriction compared to control birds and those subject to continual food restriction. BMR was positively correlated with body and organ（heart, kidney and stomach） mass. These results suggest that the Chinese bulbul adjusts to restricted food availability by utilizing its energy reserves, lowering its BMR and changing the weight of various internal organs so as to balance total energy requirements. These may all be survival strategies that allow birds to cope with unpredictable variation in food abundance.展开更多
The light-vented bulbul Pycnonotus sinensis is a small resident passerine that is found widely in central and south China,North Vietnam,and some East Asian islands,including Hainan,Taiwan and the Ryukyu Islands.Its su...The light-vented bulbul Pycnonotus sinensis is a small resident passerine that is found widely in central and south China,North Vietnam,and some East Asian islands,including Hainan,Taiwan and the Ryukyu Islands.Its subspecies status has been under considerable debate.A total of 10 subspecies have been proposed,but only 4 are widely recognized,including 1 continental taxon,P.s.sinensis,and 3 insular subspecies:P.s.hainanus,P.s.formosae and P.s.orii.Two mitochondrial DNA genes and 9 microsatellite loci were used to investigate the genetic divergence of this species,to identify the evolutionary status of 2 insular subspecies(P.s.hainanus and P.s.formosae)and to uncover probable historical causes that shaped them.The results reveal that P.s.formosae has diverged significantly from the other 2 subspecies because of a substantial time of isolation for populations on Taiwan Island.There was no significant genetic differentiation between P.s.sinensis and P.s.hainanus.The notable morphological difference in P.s.hainanus might be attributed to a rapid,recent adaptation to the tropical environment of Hainan Island.The low genetic divergence between P.s.sinensis and P.s.hainanus might result from a recent divergence or gene flow between them.Two insular subspecies of light-vented bulbul populations might have diverged recently from their continental relatives through a complex evolution history owing to island isolation,ecological isolation,and possibly even hybridization.Both P.s.hainanus and P.s.formosae should be considered important conservation units because of their morphological and genetic distinctiveness.展开更多
基金supported by the National Natural Science Foundation of China(31070366)the‘Xinmiao’Project in Zhejiang Province
文摘Chinese bulbuls （Pycnonotus sinensis） are small passerine birds that inhabit areas of central, southern and eastern China. Previous observations suggest that flee-living individuals of this species may change their food intake in response to seasonal changes in ambient temperature. In the present study, we randomly assigned Chinese bulbuls to either a 30 ~C or 10 ~C group, and measured their body mass （BM）, body temperature, gross energy intake （GEl）, digestible energy intake （DEI）, and the length and mass of their digestive tracts over 28 days of acclimation at these temperatures. As predicted, birds in the 30 ℃ group had lower body mass, GEI and DEI relative to those in the 10 ℃ group. The length and mass of the digestive tract was also lower in the 30 ℃ group and trends in these parameters were positively correlated with BM, GEl and DEI. These results suggest that Chinese bulbuls reduced their absolute energy demands at relatively high temperatures by decreasing their body mass, GEI and DEI, and digestive tract size.
基金financially supported by grants from the National Natural Science Foundation of China（31070366 and 31470472）the Zhejiang Province Natural Science Foundation（LY13C030005）
文摘Food resources play an important role in the regulation of animals’ physiology and behavior. We investigated the effect of short-term food restriction on metabolic thermogenesis of Chinese bulbuls（Pycnonotus sinensis） by measuring changes in body mass, body fat, basic metabolic rate（BMR）, and organ mass of wild-caught Chinese bulbuls from Wenzhou, China. Short-term food restriction induced a significant decrease in body mass and body fat but body mass returned to normal levels soon after food was no longer restricted. Food restriction caused a significant reduction in BMR after 7 days（P〈0.05）, which returned to normal levels after food restriction ceased. Log total BMR was positively correlated with log body mass（r2=0.126, P〈0.05）. The dry masses of livers and the digestive tract were higher in birds that had been subject to temporary food restriction than in control birds and those subject to continual food restriction（P〈0.001 and P〈0.05, respectively）. There was also significant differences in the dry mass of the lungs（P〈0.05）, heart（P〈0.01）, and spleen（P〈0.05） in birds subject to short-term food restriction compared to control birds and those subject to continual food restriction. BMR was positively correlated with body and organ（heart, kidney and stomach） mass. These results suggest that the Chinese bulbul adjusts to restricted food availability by utilizing its energy reserves, lowering its BMR and changing the weight of various internal organs so as to balance total energy requirements. These may all be survival strategies that allow birds to cope with unpredictable variation in food abundance.
基金The research was supported by the National Nature Science Foundation of the China-Guangdong Joint Fund(U0833005)the National Nature Science Foundation of China(30770305)the Guangdong Natural Science Fund(9451026001003544 and 10151026001000008).
文摘The light-vented bulbul Pycnonotus sinensis is a small resident passerine that is found widely in central and south China,North Vietnam,and some East Asian islands,including Hainan,Taiwan and the Ryukyu Islands.Its subspecies status has been under considerable debate.A total of 10 subspecies have been proposed,but only 4 are widely recognized,including 1 continental taxon,P.s.sinensis,and 3 insular subspecies:P.s.hainanus,P.s.formosae and P.s.orii.Two mitochondrial DNA genes and 9 microsatellite loci were used to investigate the genetic divergence of this species,to identify the evolutionary status of 2 insular subspecies(P.s.hainanus and P.s.formosae)and to uncover probable historical causes that shaped them.The results reveal that P.s.formosae has diverged significantly from the other 2 subspecies because of a substantial time of isolation for populations on Taiwan Island.There was no significant genetic differentiation between P.s.sinensis and P.s.hainanus.The notable morphological difference in P.s.hainanus might be attributed to a rapid,recent adaptation to the tropical environment of Hainan Island.The low genetic divergence between P.s.sinensis and P.s.hainanus might result from a recent divergence or gene flow between them.Two insular subspecies of light-vented bulbul populations might have diverged recently from their continental relatives through a complex evolution history owing to island isolation,ecological isolation,and possibly even hybridization.Both P.s.hainanus and P.s.formosae should be considered important conservation units because of their morphological and genetic distinctiveness.
