Altitudinal bird migration involves seasonal shifts up and down the altitude gradient annually.Asia as the place with the largest number of altitudinal migrants,has quite few related studies,especially for montane and...Altitudinal bird migration involves seasonal shifts up and down the altitude gradient annually.Asia as the place with the largest number of altitudinal migrants,has quite few related studies,especially for montane and temperate avifaunas.To explore the potential drivers of seasonal altitudinal migration for birds in the middle of Hengduan Mountains,we conducted a three-year investigation on breeding and non-breeding season bird communities at eight elevational bands(1200–4200 m)in the Gongga Mountains.We examined the altitudinal migration patterns and relationships between seasonal distribution shifts and species'traits of 50 species with sufficient data recorded in both seasons.We found that a large proportion of breeding birds underwent altitudinal migration and showed three migration patterns(downslope shift,upslope shift,no shift).Seasonal distribution shifts were mainly correlated with certain ecological traits.Species breeding at high and mid-elevations,nesting in scrub and being omnivorous are more likely to show downslope movements during the non-breeding season.In addition,territorially weaker species exhibited more diverse migration patterns.Notably,we found the hand-wing index(HWI)was actually more convincing than body mass in explaining altitudinal migration.These results consolidate the studies of seasonal altitudinal migration in montane birds.Our study could be used to bridge existing knowledge gaps that currently impeding effective conservation for montane avifaunas in the Hengduan Mountains.展开更多
Geographical background and dispersal ability may strongly influence assemblage dissimilarity;however,these aspects have generally been overlooked in previous large-scale beta diversity studies.Here,we examined whethe...Geographical background and dispersal ability may strongly influence assemblage dissimilarity;however,these aspects have generally been overlooked in previous large-scale beta diversity studies.Here,we examined whether the patterns and drivers of taxonomic beta diversity(TBD)and phylogenetic beta diversity(PBD)of breeding birds in China vary across(1)regions on both sides of the Hu Line,which demarcates China’s topographical,climatic,economic,and social patterns,and(2)species with different dispersal ability.TBD and PBD were calculated and partitioned into turnover and nestedness components using a moving window approach.Variables representing climate,habitat heterogeneity,and habitat quality were employed to evaluate the effects of environmental filtering.Spatial distance was considered to assess the impact of dispersal limitation.Variance partitioning analysis was applied to assess the relative roles of these variables.In general,the values of TBD and PBD were high in mountainous areas and were largely determined by environmental filtering.However,different dominant environmental filters on either side of the Hu Line led to divergent beta diversity patterns.Specifically,climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line,respectively.Additionally,bird species with stronger dispersal ability were more susceptible to environmental filtering,resulting in more homogeneous assemblages.Our results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns,and dispersal ability determines the response of assemblages to these ecological factors.Identifying a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete conclusions.Consequently,a comprehensive understanding of large-scale beta diversity patterns and effective planning of conservation strategies necessitate the consideration of both geographical background and species dispersal ability.展开更多
基金The Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0501)National Natural Science Foundation of China(No.31772478,31501851).
文摘Altitudinal bird migration involves seasonal shifts up and down the altitude gradient annually.Asia as the place with the largest number of altitudinal migrants,has quite few related studies,especially for montane and temperate avifaunas.To explore the potential drivers of seasonal altitudinal migration for birds in the middle of Hengduan Mountains,we conducted a three-year investigation on breeding and non-breeding season bird communities at eight elevational bands(1200–4200 m)in the Gongga Mountains.We examined the altitudinal migration patterns and relationships between seasonal distribution shifts and species'traits of 50 species with sufficient data recorded in both seasons.We found that a large proportion of breeding birds underwent altitudinal migration and showed three migration patterns(downslope shift,upslope shift,no shift).Seasonal distribution shifts were mainly correlated with certain ecological traits.Species breeding at high and mid-elevations,nesting in scrub and being omnivorous are more likely to show downslope movements during the non-breeding season.In addition,territorially weaker species exhibited more diverse migration patterns.Notably,we found the hand-wing index(HWI)was actually more convincing than body mass in explaining altitudinal migration.These results consolidate the studies of seasonal altitudinal migration in montane birds.Our study could be used to bridge existing knowledge gaps that currently impeding effective conservation for montane avifaunas in the Hengduan Mountains.
基金supported by the National Natural Science Foundation of China(31901220)Science and Technology Planning Project of Guangdong Province,China(2019B121202004)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2021A1515110744)Forestry Administration of Guangdong Province(DFGP Project of Fauna of Guangdong-202115)。
文摘Geographical background and dispersal ability may strongly influence assemblage dissimilarity;however,these aspects have generally been overlooked in previous large-scale beta diversity studies.Here,we examined whether the patterns and drivers of taxonomic beta diversity(TBD)and phylogenetic beta diversity(PBD)of breeding birds in China vary across(1)regions on both sides of the Hu Line,which demarcates China’s topographical,climatic,economic,and social patterns,and(2)species with different dispersal ability.TBD and PBD were calculated and partitioned into turnover and nestedness components using a moving window approach.Variables representing climate,habitat heterogeneity,and habitat quality were employed to evaluate the effects of environmental filtering.Spatial distance was considered to assess the impact of dispersal limitation.Variance partitioning analysis was applied to assess the relative roles of these variables.In general,the values of TBD and PBD were high in mountainous areas and were largely determined by environmental filtering.However,different dominant environmental filters on either side of the Hu Line led to divergent beta diversity patterns.Specifically,climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line,respectively.Additionally,bird species with stronger dispersal ability were more susceptible to environmental filtering,resulting in more homogeneous assemblages.Our results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns,and dispersal ability determines the response of assemblages to these ecological factors.Identifying a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete conclusions.Consequently,a comprehensive understanding of large-scale beta diversity patterns and effective planning of conservation strategies necessitate the consideration of both geographical background and species dispersal ability.