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.
Knowledge of the historical responses of animal species to climate changes is critical for understanding their evolutionary history and conservation.During the late Quaternary period,Southeast Asia had a larger land area than today due to lower sea levels,and its terrestrial landscape was covered by extensive forests and savannah.To date,however,the general fluctuations in landscape distribution and their impacts on the demographics history of native species during the late Quaternary periods are still disputed.Specifically,the responses of animals on Hainan Island,which is located in the northernmost region of Southeast Asia,to historical climate changes,are poorly understood.Here,we performed a series of demographic analyses based on mitochondrial DNA genes to examine the response of the resident Hainan Peacock Pheasant(Polyplectron katsumatae) to climate change.Unlike the pattern of population collapse during the ice age and expansion during the warming period,we detected a historical expansion pattern in the demographic history of Hainan Peacock Pheasant through the late Quaternary period.It was concluded that the Hainan Peacock Pheasant survived through the late Quaternary periods,despite of its currently limited distribution and population size on Hainan Island.Anthropogenic influences must be considered in conservation planning due to their impacts on currently fragmented habitats and populations.
