We use the term 'basal birds' for a relatively small number of primitive fossil birds that fall outside the major clade Ornithothoraces,which includes both modern birds and enantiorni-thines. Eight genera and ...We use the term 'basal birds' for a relatively small number of primitive fossil birds that fall outside the major clade Ornithothoraces,which includes both modern birds and enantiorni-thines. Eight genera and twelve valid species have been reported from China in the last 15 years,whereas Archaeopteryx lithographica remains the only basal bird to have been described from non-Chinese specimens(although confuciusornithid material is apparently present in North Korea).Here we briefly review the Chinese basal birds and their anatomy,phylogeny and ecology.Chinese fossils have contributed extensively to scientific understanding of early avian evolution,demon-strating collectively that basal birds were generally relatively large and morphologically and eco-logically quite diverse.Although some significant uncertainties remain,particularly with respect to the relative phylogenetic positions of Jeholornis,Sapeornis and Zhongornis,an increasingly clear picture of the first stages of avian evolution is emerging from the Chinese fossil record.展开更多
Some Miocene ratite eggshell fragments from Gashunyinadege (about 17.5 Ma) and Baogedawula (7.11 ± 0.48 Ma), Inner Mongolia, China, are described. The outer surfaces of eggshell fragments from Gashunyinadege are ...Some Miocene ratite eggshell fragments from Gashunyinadege (about 17.5 Ma) and Baogedawula (7.11 ± 0.48 Ma), Inner Mongolia, China, are described. The outer surfaces of eggshell fragments from Gashunyinadege are smooth with a sting pore pattern, while their entire thickness is around 2.12 mm. In a cross-sectional view, the surface crystal layer is very thin and the ratio of cone layer to the those from Gashunyinadege, but seem much thinner and have a lower pore density. Both characteristics fit aepyornithid-type eggshells, implying that the distribution of aepyornithid-type eggshells can be extended to East Asia. The sediments at Gashunyinadege date to approximately 17.5 Ma, implying that the specimens from this locality are relatively early examples of aepyornithid-type eggshells. Aepyornithidtype eggshells seem to have appeared in Eurasia much earlier than struthionid-type eggshells. The faunal compositions in the two localities reflect gradual drying of the Mongolian plateau during the Miocene. A reduction in the number of pores 10 Ma ago, probably occurred in response to this drying process.展开更多
The Red-breasted Flycatcher （Ficedula parva） and Taiga Flycatcher （F albicila） have long been considered having a conspecific status under the species Red-throated Flycatcher （Fparva）. Based on the studies on th...The Red-breasted Flycatcher （Ficedula parva） and Taiga Flycatcher （F albicila） have long been considered having a conspecific status under the species Red-throated Flycatcher （Fparva）. Based on the studies on the morphology, vocalizations and molecular biology, the two subspecies have recently been split into separate species that are allopatrically distributed in the Palearctic region. Before our report, there was no formal record of taxon parva in China. Between April and May of 2007, two birds of parva were recorded respectively at Potoi Island, Hong Kong SAR and Xiangyundao Tree Farm, Laoting, Hebei Province, the first known recording of this species in China. We also briefly discussed the general characteristics and field identification of Red-breasted Flycatchers in this article.展开更多
Background: The most dominant global threat to natural forests and their biodiversity is land-cover change, which has negative impacts on both species persistence and ecosystem functions. Land-cover change could alter...Background: The most dominant global threat to natural forests and their biodiversity is land-cover change, which has negative impacts on both species persistence and ecosystem functions. Land-cover change could alter animal behaviour and disrupt seed dispersal mutualisms. However, its effects on the role of bird functional traits in seed dispersal are not well studied.Methods: In the present study, we assessed the contributions of bird functional traits(behavioural traits: food habit, foraging pattern, foraging frequency, and habitat specialisation; morphological traits: weight, body length, wing length, and tail length) to both seed removal patterns and seed dispersal distances of an endangered and native tree species, Chinese yew(Taxus chinensis), in farmland, patchy habitat, and natural habitat, of southeast China.Results: We found that the ability of T. chinensis trees to form seed dispersal mutualisms with local birds varied across the different disturbed habitats. As a consequence of these mutualisms, more seeds were removed by birds from the patchy habitat than from the other two habitats. The number of seeds removed increased with bird foraging frequency. Moreover, the dispersal distance from the three habitats differed, and the longest dispersal distances were observed at both the patchy habitat and the farmland site. Seed dispersal distance increased with bird tail and wing length.Conclusions: Our results highlight the importance of bird functional traits in the seed dispersal patterns of endangered trees across disturbed forest habitats, which should be considered for tree conservation and management.展开更多
Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to...Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to clarify the population trends of and threats to waterbirds as well as to put forward conservation recommendations.Methods: We collected data of population trends of a total of 260 waterbird species in China from Wetlands International database. We calculated the number of species with increasing, declining, stable, and unknown trends. We collected threatened levels of waterbirds from the Red List of China's Vertebrates(2016), which was compiled according to the IUCN criteria of threatened species. Based on literature review, we refined the major threats to the threatened waterbird species in China.Results: Of the total 260 waterbird species in China, 84 species(32.3%) exhibited declining, 35 species(13.5%) kept stable, and 16 species(6.2%) showed increasing trends. Population trends were unknown for 125 species(48.1%). There was no significant difference in population trends between the migratory(32.4% decline) and resident(31.8% decline) species or among waterbirds distributed exclusively along coasts(28.6% decline), inland(36.6% decline), and both coasts and inland(32.5% decline). A total of 38 species(15.1% of the total) were listed as threatened species and 27 species(10.8% of the total) Near Threatened species. Habitat loss was the major threat to waterbirds, with 32 of the total 38(84.2%) threatened species being affected. In addition, 73.7%(28 species), 71.1%(27 species), and 57.9%(22 species) of the threatened species were affected by human disturbance, environmental pollution, and illegal hunting, respectively.Conclusions: We propose recommendations for waterbird conservation, including(1) strengthening conservation of nature wetlands and restoration of degraded wetlands,(2) enhancing public awareness on waterbird conservation,(3) improving the enforcement of Wildlife Protection Law and cracking down on illegal hunting,(4) carrying out longterm waterbird surveys to clarify population dynamics,(5) restoring populations of highly-threatened species through artificial intervention, and(6) promoting international and regional exchanges and cooperation to share information in waterbirds and their conservation.展开更多
This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic ...This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic University(NWPU)in China.Firstly,the main components,flight capability and flight verification of the Chinese"Dove"are presented.Then,the methods for the aerodynamic simulation and wind tunnel experiments are put forward.Secondly,the design of high-lift and high-thrust flexible flapping wings,a series of flapping mechanisms,gust-resistance layout and micro flight control/navigation system are presented.Some future studies on the application system of bionic micro air vehicles are given,including observation of natural flight creatures,aerodynamics in flight,mechanical and new material driving systems,structural mechanics,flight mechanics,and the information perception and intelligent decision-making control,which are related to research of flight bioinformatic perception and brain science.Finally,some application examples of complex flapping movements,active/passive deformation of bird wings,new low-energy motion-driven system,bionic intelligent decision-making and control/navigation are discussed.展开更多
Increasing human activities have contributed to global climate change, and thus resulted in a downward trend in the number of species and population sizes of migratory birds. This trend is closely related to a reducti...Increasing human activities have contributed to global climate change, and thus resulted in a downward trend in the number of species and population sizes of migratory birds. This trend is closely related to a reduction in habitat size and lower habitat quality. The Poyang Lake wetland in China constitutes one of Asia's largest overwintering habitats for migratory birds. Over the past 10 years, restoration projects have improved the habitat ecology of these wetlands. In this study, we assessed the changes in habitat quality for overwintering migratory birds from 2000 to 2012 near two villages in the Poyang Lake wetland using the In VEST model. Average habitat quality for migratory birds has been improved by 18.8% and47.7%. Differences in the degrees of habitat improvement can be attributed to differences in the change of habitat size and in the impact of threat sources that resulted from the combined effects of restoration and human activities in these two villages.展开更多
Old-age pension, a fundamental part of the Chinese social security system, is perceived by the Chinese government as the last support for rural-to-urban migrant workers upon retreating from the labor market. Using sur...Old-age pension, a fundamental part of the Chinese social security system, is perceived by the Chinese government as the last support for rural-to-urban migrant workers upon retreating from the labor market. Using survey data collected by the authors, this paper examines a host of factors which influence migrant workers' participation in the old-age scheme. The result shows that individual characteristics, employment status, attitudes toward old-age support and perception of the old-age pension system significantly differentiate two groups of migrant workers between those that have participated in and their counterparts who have not participated in the old-age pension schemes. Among a number of factors, age, educational attainment, holding labor contract, etc. are found to be significant factors influencing migrants' behavior participating(or not participating) the available age-pension schemes. Policy implications for how to improve the rate of participation in existing old-age pension schemes among migrant workers are drawn from the findings.展开更多
This paper will look at the importance that the migrant labors in China are doing today. The main question posed in this paper is “how migrant labors in China are contributing to rural development？”. Furthermore, t...This paper will look at the importance that the migrant labors in China are doing today. The main question posed in this paper is “how migrant labors in China are contributing to rural development？”. Furthermore, the paper will answer the following sub-questions： （1） Is migration an important factor in the development of rural areas？ （2） Can migration bridge the poverty gap between urban and rural areas？ The objectives of this paper are the following： （1） to identify the migrant labors contributions in China’s rural development; （2） to look into the importance of migration for the rural Chinese; and （3） to know and analyze the problems that migrant workers in China are facing in relation to their migratory work. Furthermore, this paper posits that migrant labors in China are contributing to rural development through their remittances, their investments, and the new knowledge and techniques that they acquired in the urban areas which they share in their home areas. In addition to that, this research looks at the migrant labors’ remittances, their investments, and the new knowledge and techniques that they acquired in their home areas as their contributions to rural development.展开更多
基金supported by the Ministry of Science and Technology of Chinathe National Natural Science Foundation of China,and the Chinese Academy of Sciences
文摘We use the term 'basal birds' for a relatively small number of primitive fossil birds that fall outside the major clade Ornithothoraces,which includes both modern birds and enantiorni-thines. Eight genera and twelve valid species have been reported from China in the last 15 years,whereas Archaeopteryx lithographica remains the only basal bird to have been described from non-Chinese specimens(although confuciusornithid material is apparently present in North Korea).Here we briefly review the Chinese basal birds and their anatomy,phylogeny and ecology.Chinese fossils have contributed extensively to scientific understanding of early avian evolution,demon-strating collectively that basal birds were generally relatively large and morphologically and eco-logically quite diverse.Although some significant uncertainties remain,particularly with respect to the relative phylogenetic positions of Jeholornis,Sapeornis and Zhongornis,an increasingly clear picture of the first stages of avian evolution is emerging from the Chinese fossil record.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-120)the Key Laboratory of Evolutionary Systematics of Vertebrates,Chinese Academy of Sciences(2010LESV007)
文摘Some Miocene ratite eggshell fragments from Gashunyinadege (about 17.5 Ma) and Baogedawula (7.11 ± 0.48 Ma), Inner Mongolia, China, are described. The outer surfaces of eggshell fragments from Gashunyinadege are smooth with a sting pore pattern, while their entire thickness is around 2.12 mm. In a cross-sectional view, the surface crystal layer is very thin and the ratio of cone layer to the those from Gashunyinadege, but seem much thinner and have a lower pore density. Both characteristics fit aepyornithid-type eggshells, implying that the distribution of aepyornithid-type eggshells can be extended to East Asia. The sediments at Gashunyinadege date to approximately 17.5 Ma, implying that the specimens from this locality are relatively early examples of aepyornithid-type eggshells. Aepyornithidtype eggshells seem to have appeared in Eurasia much earlier than struthionid-type eggshells. The faunal compositions in the two localities reflect gradual drying of the Mongolian plateau during the Miocene. A reduction in the number of pores 10 Ma ago, probably occurred in response to this drying process.
文摘The Red-breasted Flycatcher （Ficedula parva） and Taiga Flycatcher （F albicila） have long been considered having a conspecific status under the species Red-throated Flycatcher （Fparva）. Based on the studies on the morphology, vocalizations and molecular biology, the two subspecies have recently been split into separate species that are allopatrically distributed in the Palearctic region. Before our report, there was no formal record of taxon parva in China. Between April and May of 2007, two birds of parva were recorded respectively at Potoi Island, Hong Kong SAR and Xiangyundao Tree Farm, Laoting, Hebei Province, the first known recording of this species in China. We also briefly discussed the general characteristics and field identification of Red-breasted Flycatchers in this article.
基金supported by the National Natural Science Foundation of China(No.31700468)Natural Science Foundation of Jiangsu Province(No.BK2017636)the Key Subject of Ecology of Jiangsu Province
文摘Background: The most dominant global threat to natural forests and their biodiversity is land-cover change, which has negative impacts on both species persistence and ecosystem functions. Land-cover change could alter animal behaviour and disrupt seed dispersal mutualisms. However, its effects on the role of bird functional traits in seed dispersal are not well studied.Methods: In the present study, we assessed the contributions of bird functional traits(behavioural traits: food habit, foraging pattern, foraging frequency, and habitat specialisation; morphological traits: weight, body length, wing length, and tail length) to both seed removal patterns and seed dispersal distances of an endangered and native tree species, Chinese yew(Taxus chinensis), in farmland, patchy habitat, and natural habitat, of southeast China.Results: We found that the ability of T. chinensis trees to form seed dispersal mutualisms with local birds varied across the different disturbed habitats. As a consequence of these mutualisms, more seeds were removed by birds from the patchy habitat than from the other two habitats. The number of seeds removed increased with bird foraging frequency. Moreover, the dispersal distance from the three habitats differed, and the longest dispersal distances were observed at both the patchy habitat and the farmland site. Seed dispersal distance increased with bird tail and wing length.Conclusions: Our results highlight the importance of bird functional traits in the seed dispersal patterns of endangered trees across disturbed forest habitats, which should be considered for tree conservation and management.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.31572280 and 31071939)
文摘Background: China is one of the countries with abundant waterbird diversity. Over the past decades, China's waterbirds have suffered increasing threats from direct and indirect human activities. It is important to clarify the population trends of and threats to waterbirds as well as to put forward conservation recommendations.Methods: We collected data of population trends of a total of 260 waterbird species in China from Wetlands International database. We calculated the number of species with increasing, declining, stable, and unknown trends. We collected threatened levels of waterbirds from the Red List of China's Vertebrates(2016), which was compiled according to the IUCN criteria of threatened species. Based on literature review, we refined the major threats to the threatened waterbird species in China.Results: Of the total 260 waterbird species in China, 84 species(32.3%) exhibited declining, 35 species(13.5%) kept stable, and 16 species(6.2%) showed increasing trends. Population trends were unknown for 125 species(48.1%). There was no significant difference in population trends between the migratory(32.4% decline) and resident(31.8% decline) species or among waterbirds distributed exclusively along coasts(28.6% decline), inland(36.6% decline), and both coasts and inland(32.5% decline). A total of 38 species(15.1% of the total) were listed as threatened species and 27 species(10.8% of the total) Near Threatened species. Habitat loss was the major threat to waterbirds, with 32 of the total 38(84.2%) threatened species being affected. In addition, 73.7%(28 species), 71.1%(27 species), and 57.9%(22 species) of the threatened species were affected by human disturbance, environmental pollution, and illegal hunting, respectively.Conclusions: We propose recommendations for waterbird conservation, including(1) strengthening conservation of nature wetlands and restoration of degraded wetlands,(2) enhancing public awareness on waterbird conservation,(3) improving the enforcement of Wildlife Protection Law and cracking down on illegal hunting,(4) carrying out longterm waterbird surveys to clarify population dynamics,(5) restoring populations of highly-threatened species through artificial intervention, and(6) promoting international and regional exchanges and cooperation to share information in waterbirds and their conservation.
基金supported by the National Key Research and Development Program of China(No.2017YFB1300102)the National Natural Science Foundation of China(No.U1613227)。
文摘This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic University(NWPU)in China.Firstly,the main components,flight capability and flight verification of the Chinese"Dove"are presented.Then,the methods for the aerodynamic simulation and wind tunnel experiments are put forward.Secondly,the design of high-lift and high-thrust flexible flapping wings,a series of flapping mechanisms,gust-resistance layout and micro flight control/navigation system are presented.Some future studies on the application system of bionic micro air vehicles are given,including observation of natural flight creatures,aerodynamics in flight,mechanical and new material driving systems,structural mechanics,flight mechanics,and the information perception and intelligent decision-making control,which are related to research of flight bioinformatic perception and brain science.Finally,some application examples of complex flapping movements,active/passive deformation of bird wings,new low-energy motion-driven system,bionic intelligent decision-making and control/navigation are discussed.
基金financial support of the Asia–Pacific Network for Global Change Research project (reference number: ARCP2011-15NMYZhen)Technical Support Program of the Ministry of Science and Technology of China (No. 2013BAC03B04)the Key Project for the Strategic Science Plan of the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences (No. 2012ZD007)
文摘Increasing human activities have contributed to global climate change, and thus resulted in a downward trend in the number of species and population sizes of migratory birds. This trend is closely related to a reduction in habitat size and lower habitat quality. The Poyang Lake wetland in China constitutes one of Asia's largest overwintering habitats for migratory birds. Over the past 10 years, restoration projects have improved the habitat ecology of these wetlands. In this study, we assessed the changes in habitat quality for overwintering migratory birds from 2000 to 2012 near two villages in the Poyang Lake wetland using the In VEST model. Average habitat quality for migratory birds has been improved by 18.8% and47.7%. Differences in the degrees of habitat improvement can be attributed to differences in the change of habitat size and in the impact of threat sources that resulted from the combined effects of restoration and human activities in these two villages.
基金supported by Sichuan University[grant number skzx2016-sb72]
文摘Old-age pension, a fundamental part of the Chinese social security system, is perceived by the Chinese government as the last support for rural-to-urban migrant workers upon retreating from the labor market. Using survey data collected by the authors, this paper examines a host of factors which influence migrant workers' participation in the old-age scheme. The result shows that individual characteristics, employment status, attitudes toward old-age support and perception of the old-age pension system significantly differentiate two groups of migrant workers between those that have participated in and their counterparts who have not participated in the old-age pension schemes. Among a number of factors, age, educational attainment, holding labor contract, etc. are found to be significant factors influencing migrants' behavior participating(or not participating) the available age-pension schemes. Policy implications for how to improve the rate of participation in existing old-age pension schemes among migrant workers are drawn from the findings.
文摘This paper will look at the importance that the migrant labors in China are doing today. The main question posed in this paper is “how migrant labors in China are contributing to rural development？”. Furthermore, the paper will answer the following sub-questions： （1） Is migration an important factor in the development of rural areas？ （2） Can migration bridge the poverty gap between urban and rural areas？ The objectives of this paper are the following： （1） to identify the migrant labors contributions in China’s rural development; （2） to look into the importance of migration for the rural Chinese; and （3） to know and analyze the problems that migrant workers in China are facing in relation to their migratory work. Furthermore, this paper posits that migrant labors in China are contributing to rural development through their remittances, their investments, and the new knowledge and techniques that they acquired in the urban areas which they share in their home areas. In addition to that, this research looks at the migrant labors’ remittances, their investments, and the new knowledge and techniques that they acquired in their home areas as their contributions to rural development.
