With continually increasing urbanization,the land cover in urban areas continues to change,resulting in the loss of biodiversity.Birds are highly sensitive to changes in habitat.Most forest birds perch on plants that ...With continually increasing urbanization,the land cover in urban areas continues to change,resulting in the loss of biodiversity.Birds are highly sensitive to changes in habitat.Most forest birds perch on plants that provide increased safety to reduce the risk of predation,and small birds may also consider insulation when using roosting plants in winter because of cold weather.Landscaping plants thus shape the nocturnal roosting environment of urban birds,and proper planting is essential for the survival of birds at night.The use of roosting plants by urban birds should therefore be studied to provide a reference for landscaping.In the current study,we observed 1865 nocturnal roosting birds in Beijing from 2021 to 2022,with 23 species of birds from 12 families and 45 species of plants from 22 families recorded.Juniperus chinensis exhibited the highest bird rarity-weighted richness,followed by Fraxinus pennsylvanica,Phyllostachys propinqua,Pinus tabuliformis,and Ulmus pumila.The diameter at breast height,tree height,and crown width of plants used by birds was largest in summer and smallest in winter,and the perch height of birds was the highest in spring and summer and the lowest in winter.Birds used the highest proportion of deciduous plants in summer and the highest proportion of evergreen plants in winter.A significant seasonal difference in the use of evergreen and deciduous plants by small birds was noted,with a preference for deciduous plants in summer and evergreen plants in winter,while this preference was not found in large birds.These findings indicate that evergreen plants provide a vital nocturnal roosting environment for small birds in winter.To provide a better nocturnal roosting habitat for urban birds,we recommend paying attention to the combination of evergreen and deciduous plants when carrying out landscape construction.展开更多
Background:Anthropogenic disturbance can negatively affect an animal's energy budget by evoking movement responses.Existing research focuses mainly on immediate displacement as a disturbance effect,since this can ...Background:Anthropogenic disturbance can negatively affect an animal's energy budget by evoking movement responses.Existing research focuses mainly on immediate displacement as a disturbance effect,since this can be easily observed in the field. However, effects on movement over longer timescales are poorly examined and it is largely unknown if and to what extent they reflect immediate responses.Longer-term responses could for example be larger than immediate responses if birds, after disturbance, return to the original location and thereby travel twice the immediate disturbed distance. Methods:We combined GPS tracking data with observational data to quantify the effects of anthropogenic (air force and walkers) and non-anthropogenic disturbances on distances travelled by roosting Eurasian Oystercatchers (Haematopus ostralegus) during the non-breeding season. We compared immediate displacement after a disturbance with distance travelled during the entire high tide period (longer-term response), while accounting for environmental factors.Additionally,we calculated energy expenditure due to disturbance based on observed disturbance frequencies.Results:Disturbance resulted in an immediate displacement response of ~200 m (median).Air force disturbances tended to yield larger immediate responses than walker and,especially,than non-anthropogenic disturbances.Longer-term responses and immediate responses were approximately similar,suggesting that,over longer timescales,spatial disturbance effects in the study area remain confined to immediate effects.However,disturbances were infrequent (0.17 disturbances per bird per hour) and most disturbances were of natural origin (62%).Consequently, anthropogenic disturbance of roosting oystercatchers in the study area on average costs 0.08% of the daily energy expenditure. Conclusions:Our results suggest that immediate spatial responses to disturbance can be a useful proxy for spatial responses over longer timescales.Over the non-exhaustive range of conditions investigated,energetic consequences of spatial disturbance responses for an oystercatcher in the study area are marginal due to low disturbance levels.展开更多
Background:Communal roosting is a common avian social behaviour,which potentially provides foraging benefits,predation avoidance or thermoregulation in birds.To identify the crucial environmental factors associated wi...Background:Communal roosting is a common avian social behaviour,which potentially provides foraging benefits,predation avoidance or thermoregulation in birds.To identify the crucial environmental factors associated with roost site selection,most studies have focused on the comparison of physical characteristics between roosts and non-roosts.However,the differences among roosts have usually been neglected and the causes of roost switching have seldom been investigated.Methods:To explore the variations among roost sites and assess the most influential environmental factors related to seasonal roost switching,we conducted a 105-day observation on an introduced population of critically endan-gered Yellow-crested Cockatoo(Cacatua sulphurea)in an urban environment in Hong Kong from 2014 to 2016.We identified seven roost sites that were occupied in different seasons and then measured their microhabitat character-istics in terms of land use types,human disturbance and microclimate temperature.To quantify these differences,we used Pearson’s chi-squared test,partial least squares determinant analysis(PLS-DA)and one-way repeated measures ANOVA,respectively.Results:Our results distinguished roost sites occupied in three seasons,i.e.spring,summer and winter roosts,using several microhabitat characteristics.The land use types were significantly associated with roosts,where spring roosts were usually located in tree-dominated areas,which are the major feeding grounds.The discriminant analysis on human disturbance variables indicated that summer roosts were positively associated with night illumination.The microhabitat temperatures of winter roosts were significantly higher than those of most other roosts on cold nights.Conclusions:The results highlighted significant variations among roosts,and seasonal roost switching was likely driven by specific microhabitat characteristics of each roost site,such as microclimate.It also helps us understand the behavioural adaptation of birds to urban environments.展开更多
[ Objective] To represent characteristics of roosting-sites of blue-eared pheasant （ Crossoptilon auritum） in breeding season and the fac- tors affecting selection of roosting-sites. [ Method] A total of 32 night ro...[ Objective] To represent characteristics of roosting-sites of blue-eared pheasant （ Crossoptilon auritum） in breeding season and the fac- tors affecting selection of roosting-sites. [ Method] A total of 32 night roosting-sites of blue-eared pheasants and 45 control sites were selected from the Gahai-Zecha Nature Reserve in Gansu Province in breeding season. Fifteen habitat factors including landform, vegetation and distance were surveyed. Chi-square test and test of significance were conducted. And major environmental factors affecting selection of roosting-sites were deter- mined by principal component analysis. [ Result] As shown by the chi-square analysis, roosting-sites were characterized by sunny slope; steeper slope; higher arbor coverage, arbor height and trunk diameter; and lower shrub coverage, shrub height, grass coverage and grass height. The principal component analysis showed that shrub coverage, shrub height, distance to road, moss coverage and grass height were the key factors for the blue-eared pheasants to choose roosting-sites. [ Conclusion] Blue-eared pheasants usually select coniferous forest on sunny and steeper slope which has many high shrubs as their night roosting-sites.展开更多
选注者言:本文描述的是澳大利亚的一个鳄鱼保护区里的故事,内容生动可读,信息丰富动人。但是,就语言表达而言,本文出现的一个现象值得读者注意。首先,本文标题中的Rule the Roost是一个英语成语,含义是:当家;为首;为王。而初学者则容易...选注者言:本文描述的是澳大利亚的一个鳄鱼保护区里的故事,内容生动可读,信息丰富动人。但是,就语言表达而言,本文出现的一个现象值得读者注意。首先,本文标题中的Rule the Roost是一个英语成语,含义是:当家;为首;为王。而初学者则容易将此成语当作Rule+the Roost(统治+栖息处)去理解。所幸的是,聪明的读者也能从“统治+栖息处”的意思推断出“当家;为首;为王”的理解,但是,并非所有的英语成语均能如此顺利“推断”,比如,本文的结尾处,出现了plunge pool。什么叫plunge pool是一个习惯搭配,意思是“瀑布下的水潭”,假如,读者不知道这个习惯搭配,而是根据plunge+pool的意思“游泳+池”(plunge确实有“游泳”的意思)去猜想,那就麻烦了!展开更多
基金supported by the Beijing Municipal Commission of Science and Technology(No.D171100007217002).
文摘With continually increasing urbanization,the land cover in urban areas continues to change,resulting in the loss of biodiversity.Birds are highly sensitive to changes in habitat.Most forest birds perch on plants that provide increased safety to reduce the risk of predation,and small birds may also consider insulation when using roosting plants in winter because of cold weather.Landscaping plants thus shape the nocturnal roosting environment of urban birds,and proper planting is essential for the survival of birds at night.The use of roosting plants by urban birds should therefore be studied to provide a reference for landscaping.In the current study,we observed 1865 nocturnal roosting birds in Beijing from 2021 to 2022,with 23 species of birds from 12 families and 45 species of plants from 22 families recorded.Juniperus chinensis exhibited the highest bird rarity-weighted richness,followed by Fraxinus pennsylvanica,Phyllostachys propinqua,Pinus tabuliformis,and Ulmus pumila.The diameter at breast height,tree height,and crown width of plants used by birds was largest in summer and smallest in winter,and the perch height of birds was the highest in spring and summer and the lowest in winter.Birds used the highest proportion of deciduous plants in summer and the highest proportion of evergreen plants in winter.A significant seasonal difference in the use of evergreen and deciduous plants by small birds was noted,with a preference for deciduous plants in summer and evergreen plants in winter,while this preference was not found in large birds.These findings indicate that evergreen plants provide a vital nocturnal roosting environment for small birds in winter.To provide a better nocturnal roosting habitat for urban birds,we recommend paying attention to the combination of evergreen and deciduous plants when carrying out landscape construction.
基金provided by the Applied and Engineering Sciences domain of the Netherlands Organisation for Scientific Research(NWO-TTW 14638)by the Royal Netherlands Air Force,Birdlife Netherlands,NAM gas exploration,and Deltares
文摘Background:Anthropogenic disturbance can negatively affect an animal's energy budget by evoking movement responses.Existing research focuses mainly on immediate displacement as a disturbance effect,since this can be easily observed in the field. However, effects on movement over longer timescales are poorly examined and it is largely unknown if and to what extent they reflect immediate responses.Longer-term responses could for example be larger than immediate responses if birds, after disturbance, return to the original location and thereby travel twice the immediate disturbed distance. Methods:We combined GPS tracking data with observational data to quantify the effects of anthropogenic (air force and walkers) and non-anthropogenic disturbances on distances travelled by roosting Eurasian Oystercatchers (Haematopus ostralegus) during the non-breeding season. We compared immediate displacement after a disturbance with distance travelled during the entire high tide period (longer-term response), while accounting for environmental factors.Additionally,we calculated energy expenditure due to disturbance based on observed disturbance frequencies.Results:Disturbance resulted in an immediate displacement response of ~200 m (median).Air force disturbances tended to yield larger immediate responses than walker and,especially,than non-anthropogenic disturbances.Longer-term responses and immediate responses were approximately similar,suggesting that,over longer timescales,spatial disturbance effects in the study area remain confined to immediate effects.However,disturbances were infrequent (0.17 disturbances per bird per hour) and most disturbances were of natural origin (62%).Consequently, anthropogenic disturbance of roosting oystercatchers in the study area on average costs 0.08% of the daily energy expenditure. Conclusions:Our results suggest that immediate spatial responses to disturbance can be a useful proxy for spatial responses over longer timescales.Over the non-exhaustive range of conditions investigated,energetic consequences of spatial disturbance responses for an oystercatcher in the study area are marginal due to low disturbance levels.
基金supported by the Hong Kong Environment and Conservation Fund(ECF Project 02/2014)the United College Endowment Fund of The Chinese University of Hong Kong.
文摘Background:Communal roosting is a common avian social behaviour,which potentially provides foraging benefits,predation avoidance or thermoregulation in birds.To identify the crucial environmental factors associated with roost site selection,most studies have focused on the comparison of physical characteristics between roosts and non-roosts.However,the differences among roosts have usually been neglected and the causes of roost switching have seldom been investigated.Methods:To explore the variations among roost sites and assess the most influential environmental factors related to seasonal roost switching,we conducted a 105-day observation on an introduced population of critically endan-gered Yellow-crested Cockatoo(Cacatua sulphurea)in an urban environment in Hong Kong from 2014 to 2016.We identified seven roost sites that were occupied in different seasons and then measured their microhabitat character-istics in terms of land use types,human disturbance and microclimate temperature.To quantify these differences,we used Pearson’s chi-squared test,partial least squares determinant analysis(PLS-DA)and one-way repeated measures ANOVA,respectively.Results:Our results distinguished roost sites occupied in three seasons,i.e.spring,summer and winter roosts,using several microhabitat characteristics.The land use types were significantly associated with roosts,where spring roosts were usually located in tree-dominated areas,which are the major feeding grounds.The discriminant analysis on human disturbance variables indicated that summer roosts were positively associated with night illumination.The microhabitat temperatures of winter roosts were significantly higher than those of most other roosts on cold nights.Conclusions:The results highlighted significant variations among roosts,and seasonal roost switching was likely driven by specific microhabitat characteristics of each roost site,such as microclimate.It also helps us understand the behavioural adaptation of birds to urban environments.
基金funded by the China Natural Science Foundation ( 30530130)Natural Science Basic Research Plan in Shaanxi Province of China ( 2010JQ3001)+1 种基金Scientific Research Program Funded by Shaanxi Provincial Education Department ( 2010JK543)Graduate Program of Weinan Teachers University ( 10YKZ055)
文摘[ Objective] To represent characteristics of roosting-sites of blue-eared pheasant （ Crossoptilon auritum） in breeding season and the fac- tors affecting selection of roosting-sites. [ Method] A total of 32 night roosting-sites of blue-eared pheasants and 45 control sites were selected from the Gahai-Zecha Nature Reserve in Gansu Province in breeding season. Fifteen habitat factors including landform, vegetation and distance were surveyed. Chi-square test and test of significance were conducted. And major environmental factors affecting selection of roosting-sites were deter- mined by principal component analysis. [ Result] As shown by the chi-square analysis, roosting-sites were characterized by sunny slope; steeper slope; higher arbor coverage, arbor height and trunk diameter; and lower shrub coverage, shrub height, grass coverage and grass height. The principal component analysis showed that shrub coverage, shrub height, distance to road, moss coverage and grass height were the key factors for the blue-eared pheasants to choose roosting-sites. [ Conclusion] Blue-eared pheasants usually select coniferous forest on sunny and steeper slope which has many high shrubs as their night roosting-sites.
