Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coa...Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coastal Waterbird Census was organized by volunteer birdwatchers in China's coastal region.Waterbirds were surveyed synchronously once every month at 14 sites,as well as irregularly at a further 18 sites,between September 2005 and December 2013.Results:A total of 75 species of waterbirds met the 1 % population level Ramsar listing criterion at least once at one site.The number of birds of the following species accounted for over 20 % of the total flyway populations at a single site:Mute Swan(Cygnus olor),Siberia Crane(Grus leucogeranus),Far Eastern Oystercatcher(Haematopus osculans),Bar-tailed Godwit(Limosa lapponica),Spotted Greenshank(Tringa guttifer),Great Knot(Calidris tenuirostris),Spoon-billed Sandpiper(Calidris pygmeus),Saunders' s Gull(Larus saundersi),Relict Gull(Larus relictus),Great Cormorant(Phalacrocorax carbo),Eurasian Spoonbill(Platalea leucorodia),Black-faced Spoonbill(Platalea minor) and Dalmatian Pelican(Pelecanus crispus).A total of 26 sites supported at least one species of which their number met the1 % criterion.Forty-two species met the 1 % criterion in the Yellow River Delta,Shandong;29 at the Cangzhou coast,Hebei and 26 species at the Lianyungang coast,Jiangsu.Conclusions:The results highlight the international importance of China's coastal wetlands for waterbirds.This study also demonstrates that participation of local birdwatchers in waterbird surveys results in data that are invaluable not only for understanding the current status of waterbirds in China's coastal regions but also for waterbird conservation and management.展开更多
Sex differences in morphology provide key information for understanding a species'morphological adaptations in relation to the evolution of sexual selection.In migratory birds,morphological traits have adapted to ...Sex differences in morphology provide key information for understanding a species'morphological adaptations in relation to the evolution of sexual selection.In migratory birds,morphological traits have adapted to long-distance travel,and sexual dimorphism is typically related to sex-differential migration phenology.Little Buntings(Emberiza pusilla)have one of the longest migrations and are the least dichromatic species among the Emberiza buntings.In this study,we measured sexual size dimorphism and sexual dichromatism of Little Buntings in relation to the spring arrival dates at a stopover site in Korea.Wing length was the most important predictor for identifying sex;the wings of males were longer than those of females.Males also had a significantly stronger chestnut color of the head feathers than females,but this color difference was more prominent in the spring than in the fall.Males arrived earlier than females by four days.Arrival dates correlated with both size and color,but unlike other bunting species previously studied in the same area,there was no clear sex-differential trend in the relationship between arrival date and morphological characteristics.Seasonal differences in the degree of sexual dichromatism suggest that chestnut plumage coloration can be used as a social or sexual signal of males in the breeding season.The correlation of size and color to early arrival regardless of sex may indicate that a preference for assortative mating exists or that a sex-differential migration strategy is not clearly defined in the early stages of northward migration.Our findings on the sexual dimorphism of Little Buntings provide insight into the evolution of the sex-differential migration of buntings in the East Asian Flyway.展开更多
文摘Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coastal Waterbird Census was organized by volunteer birdwatchers in China's coastal region.Waterbirds were surveyed synchronously once every month at 14 sites,as well as irregularly at a further 18 sites,between September 2005 and December 2013.Results:A total of 75 species of waterbirds met the 1 % population level Ramsar listing criterion at least once at one site.The number of birds of the following species accounted for over 20 % of the total flyway populations at a single site:Mute Swan(Cygnus olor),Siberia Crane(Grus leucogeranus),Far Eastern Oystercatcher(Haematopus osculans),Bar-tailed Godwit(Limosa lapponica),Spotted Greenshank(Tringa guttifer),Great Knot(Calidris tenuirostris),Spoon-billed Sandpiper(Calidris pygmeus),Saunders' s Gull(Larus saundersi),Relict Gull(Larus relictus),Great Cormorant(Phalacrocorax carbo),Eurasian Spoonbill(Platalea leucorodia),Black-faced Spoonbill(Platalea minor) and Dalmatian Pelican(Pelecanus crispus).A total of 26 sites supported at least one species of which their number met the1 % criterion.Forty-two species met the 1 % criterion in the Yellow River Delta,Shandong;29 at the Cangzhou coast,Hebei and 26 species at the Lianyungang coast,Jiangsu.Conclusions:The results highlight the international importance of China's coastal wetlands for waterbirds.This study also demonstrates that participation of local birdwatchers in waterbird surveys results in data that are invaluable not only for understanding the current status of waterbirds in China's coastal regions but also for waterbird conservation and management.
基金supported by the New Faculty Startup Fund from Seoul National University (Grant No.500-20200268)supported by the National Research Foundation of Korea (NRF) grants funded by the Republic of Korea Government (Ministry of EducationNRF2018R1D1A1B07050135 & NRF-2019R1I1A1A01063760)
文摘Sex differences in morphology provide key information for understanding a species'morphological adaptations in relation to the evolution of sexual selection.In migratory birds,morphological traits have adapted to long-distance travel,and sexual dimorphism is typically related to sex-differential migration phenology.Little Buntings(Emberiza pusilla)have one of the longest migrations and are the least dichromatic species among the Emberiza buntings.In this study,we measured sexual size dimorphism and sexual dichromatism of Little Buntings in relation to the spring arrival dates at a stopover site in Korea.Wing length was the most important predictor for identifying sex;the wings of males were longer than those of females.Males also had a significantly stronger chestnut color of the head feathers than females,but this color difference was more prominent in the spring than in the fall.Males arrived earlier than females by four days.Arrival dates correlated with both size and color,but unlike other bunting species previously studied in the same area,there was no clear sex-differential trend in the relationship between arrival date and morphological characteristics.Seasonal differences in the degree of sexual dichromatism suggest that chestnut plumage coloration can be used as a social or sexual signal of males in the breeding season.The correlation of size and color to early arrival regardless of sex may indicate that a preference for assortative mating exists or that a sex-differential migration strategy is not clearly defined in the early stages of northward migration.Our findings on the sexual dimorphism of Little Buntings provide insight into the evolution of the sex-differential migration of buntings in the East Asian Flyway.
