In tropical and subtropical forest ecosystems,cavities formed by decay processes are a key but scarce resource for birds that nest and roost in them,which makes them a highly sensitive group to logging.The piedmont fo...In tropical and subtropical forest ecosystems,cavities formed by decay processes are a key but scarce resource for birds that nest and roost in them,which makes them a highly sensitive group to logging.The piedmont forest of northwestern Argentina is a complex ecosystem with 113 tree and 120 bird species.It has high logging pressure on the few,well-conserved forest remnants,complicating the delineation of sustainable management guidelines for each tree or bird species in a short time.Our objective was to reduce the complexity of subtropical forests by grouping tree species according to the characteristics used by secondary cavity-nesting birds(i.e.non excavators).In the piedmont forest,50 plots of 0.25 ha were sampled to record cavity trees and cavity characteristics.These were then used in a cluster analysis to form tree groups.Additionally,cavities were searched to identify the bird species using the decay-formed cavities.A total of 187 cavity trees,comprising 23 tree species,were recorded,and these formed four tree groups or clusters.We recorded 86 cavities that were used by secondary cavitynesting bird species.The four tree groups were unequally used by secondary cavity nesters.The tree group that included valuable timber species(Myroxylon peruiferum,Anadenanthera colubrina and Calycophyllum multiflorum)and had the greatest cavity availability represented 71%of total cavity use.Another tree group with valuable timber species(Cedrela balansae and Amburana cearensis),measured>73 cm DBH and>21 m tall,had cavity entrances>0.10 cm2,and contributed 14%of all cavity use by birds.A third group had no highly economically valuable tree species,and included the snag category(i.e.standing dead trees)as well as a 15%of cavity use.The fourth tree group had a DBH<0.40 cm,only one highly economically valuable tree species(Cordia trichotoma),and supported no cavity use.The clustering of subtropical trees can reduce the complexity of these forests,hence easing their management by focusing on those groups with tree species showing similar characteristics and providing suitable nesting sites for secondary cavity-nesting birds.展开更多
The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ...The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ecology is thus poorly studied.In this study,we analysed light-level geolocation data collected from six Beijing Swifts for the first time.Our results showed that geolocators can make comprehensive inference of their incubation period and behaviour.As a cost-effective and non-invasive method,geolocators can not only facilitate discovering migration routes,but also can be widely applied in the study of avian reproductive behaviour,especially in cavity-nesting bird species.We further discussed the characteristics and merits of this method and compared with other conventional nest-monitoring methods in recording birds.展开更多
Mediterranean woodland environments are characterised by high spatial and temporal heterogeneity,which means the inhabiting species face a wide variety of selective pressures.Species may respond differently to habitat...Mediterranean woodland environments are characterised by high spatial and temporal heterogeneity,which means the inhabiting species face a wide variety of selective pressures.Species may respond differently to habitat heterogeneity and so distinct eco-evolutionary scenarios may be responsible for the inter-habitat variability in reproductive strategies observed in certain species.The inter-forest variability of some reproductive traits in passerines has been examined by comparing forest patches or separated fragments.However,there is still little information regarding how such highly mobile animals adjust their breeding performance across continuous and heterogeneous woodlands.Here we studied the reproductive performance of a population of Blue Tits(Cyanistes caeruleus) in an area of continuous Mediterranean woodland that included two mountain slopes and four different types of forest,ranging from deciduous oak forests to perennial non-oak forests.We studied the habitat heterogeneity and inter-forest phenotypic variation in terms of reproductive performance and adult and nestling biometry,besides also exploring the effects of ectoparasites on Blue Tit reproduction.Eggs were laid earliest in deciduous Pyrenean Oak(Quercus pyrenaica) forests,while clutch size and the number of fledglings were highest in the humid Pyrenean Oak forest,which had the greatest tree coverage and most humid climate,and lowest in the coniferous Scots Pine(Pinus sylvestris) forest.There were no inter-forest differences in hatching(percentage of nests with at least one egg hatched) and fledging(percentage of nests in which at least one nestling fledged)success.Similarly,there were no inter-forest differences in adult and nestling biometry,but adults that raised more fledglings had a lower body mass,while males whose females laid larger clutches had smaller tarsi.Most ectoparasites did not affect Blue Tit reproduction,although Culicoides had a negative impact on nestling body mass.These results suggest that Blue Tits can adjust their reproductive effort to the forest where they breed even across a very small spatial scale.Different eco-evolutionary scenarios,such as phenotypic plasticity or genetic structuring and local adaptation,might explain the phenotypic differentiation in the reproductive strategies observed over small areas in woodlands.展开更多
Providing nest-boxes as surrogate tree cavities can be of great importance to increase the breeding populations of cavity-nesting birds in managed forests.However,the exact placement of nest-boxes should be taken into...Providing nest-boxes as surrogate tree cavities can be of great importance to increase the breeding populations of cavity-nesting birds in managed forests.However,the exact placement of nest-boxes should be taken into consideration to enhance their occupancy according to species-specific preferences.In this study,we investigated which factors can better predict nest-box occupancy by the Great Tit(Parus major)in eucalypt plantations.We used generalised linear mixed-effects models to analyse the influence of topography,nest-box positioning,vegetation cover and landscape variables on three-year occupancy records from 80 newly provided nest-boxes.Non-random patterns of nest-box occupancy were found with respect to all categories except topography.Results suggest that Great Tits prefer to occupy high-placed nest-boxes,close to areas that can provide them with supplementary resources either within or in the vicinity of the stand(i.e.,trees other than eucalypts,riparian vegetation,and large patches of adjacent habitats).Overall,this study provides important recommendations for nest-box placement and spatial distribution in managed forests and enhances the potential of nest-box interventions as a biodiversity offset and management tool.展开更多
基金This work was supported with Funds from Agencia Nacional de Promoción Científica y Tecnoló gica (PICT 2012-0892,BID, PICT 2014-1388, BID)CONICET (PIP 112-201201-00259 CO)+2 种基金CONICET-UNJU (PIO 1402014100133)UNJU (SECTER A 0176 and B 046)CEBio NGO, Idea Wild, Association of Field Ornithologists, Optic for the Tropic, and Rufford Small Grants
文摘In tropical and subtropical forest ecosystems,cavities formed by decay processes are a key but scarce resource for birds that nest and roost in them,which makes them a highly sensitive group to logging.The piedmont forest of northwestern Argentina is a complex ecosystem with 113 tree and 120 bird species.It has high logging pressure on the few,well-conserved forest remnants,complicating the delineation of sustainable management guidelines for each tree or bird species in a short time.Our objective was to reduce the complexity of subtropical forests by grouping tree species according to the characteristics used by secondary cavity-nesting birds(i.e.non excavators).In the piedmont forest,50 plots of 0.25 ha were sampled to record cavity trees and cavity characteristics.These were then used in a cluster analysis to form tree groups.Additionally,cavities were searched to identify the bird species using the decay-formed cavities.A total of 187 cavity trees,comprising 23 tree species,were recorded,and these formed four tree groups or clusters.We recorded 86 cavities that were used by secondary cavitynesting bird species.The four tree groups were unequally used by secondary cavity nesters.The tree group that included valuable timber species(Myroxylon peruiferum,Anadenanthera colubrina and Calycophyllum multiflorum)and had the greatest cavity availability represented 71%of total cavity use.Another tree group with valuable timber species(Cedrela balansae and Amburana cearensis),measured>73 cm DBH and>21 m tall,had cavity entrances>0.10 cm2,and contributed 14%of all cavity use by birds.A third group had no highly economically valuable tree species,and included the snag category(i.e.standing dead trees)as well as a 15%of cavity use.The fourth tree group had a DBH<0.40 cm,only one highly economically valuable tree species(Cordia trichotoma),and supported no cavity use.The clustering of subtropical trees can reduce the complexity of these forests,hence easing their management by focusing on those groups with tree species showing similar characteristics and providing suitable nesting sites for secondary cavity-nesting birds.
基金funded by SHAN SHUI Conservation Centre,Beijing。
文摘The Beijing Swift(Apus apus pekinensis)is a typical cavity-nesting bird that often nests inside holes and crevices in old architectures.Direct observation of their breeding behaviour is challenging and their breeding ecology is thus poorly studied.In this study,we analysed light-level geolocation data collected from six Beijing Swifts for the first time.Our results showed that geolocators can make comprehensive inference of their incubation period and behaviour.As a cost-effective and non-invasive method,geolocators can not only facilitate discovering migration routes,but also can be widely applied in the study of avian reproductive behaviour,especially in cavity-nesting bird species.We further discussed the characteristics and merits of this method and compared with other conventional nest-monitoring methods in recording birds.
基金funded by two projects in the National Plan of the Spanish Ministry of Economy and Competition (CGL2014-55969-P and CGL2017-84938-P)a project of the Andalusian Regional Government (A-RNM-48-UGR20)+4 种基金financed with ERDF funds from the European Union (EU)JGB was supported by a FPU pre-doctoral contract from the Spanish Ministry of Education (FPU18/03034)MC by a grant from the Spanish Ministry of Economy and Competition through the SeveroOchoa Programme for Centres of Excellence in ResearchDevelopment and Innovation (R+D+I)(SEV-2012-0262),contract No.SVP-2014-068620JLRS and EP were funded by Erasmus+grants from the EU.
文摘Mediterranean woodland environments are characterised by high spatial and temporal heterogeneity,which means the inhabiting species face a wide variety of selective pressures.Species may respond differently to habitat heterogeneity and so distinct eco-evolutionary scenarios may be responsible for the inter-habitat variability in reproductive strategies observed in certain species.The inter-forest variability of some reproductive traits in passerines has been examined by comparing forest patches or separated fragments.However,there is still little information regarding how such highly mobile animals adjust their breeding performance across continuous and heterogeneous woodlands.Here we studied the reproductive performance of a population of Blue Tits(Cyanistes caeruleus) in an area of continuous Mediterranean woodland that included two mountain slopes and four different types of forest,ranging from deciduous oak forests to perennial non-oak forests.We studied the habitat heterogeneity and inter-forest phenotypic variation in terms of reproductive performance and adult and nestling biometry,besides also exploring the effects of ectoparasites on Blue Tit reproduction.Eggs were laid earliest in deciduous Pyrenean Oak(Quercus pyrenaica) forests,while clutch size and the number of fledglings were highest in the humid Pyrenean Oak forest,which had the greatest tree coverage and most humid climate,and lowest in the coniferous Scots Pine(Pinus sylvestris) forest.There were no inter-forest differences in hatching(percentage of nests with at least one egg hatched) and fledging(percentage of nests in which at least one nestling fledged)success.Similarly,there were no inter-forest differences in adult and nestling biometry,but adults that raised more fledglings had a lower body mass,while males whose females laid larger clutches had smaller tarsi.Most ectoparasites did not affect Blue Tit reproduction,although Culicoides had a negative impact on nestling body mass.These results suggest that Blue Tits can adjust their reproductive effort to the forest where they breed even across a very small spatial scale.Different eco-evolutionary scenarios,such as phenotypic plasticity or genetic structuring and local adaptation,might explain the phenotypic differentiation in the reproductive strategies observed over small areas in woodlands.
基金co-financed by Funda?ao para a Ciencia e a Tecnologia(FCT)the European Regional Development Fund(FEDER)through Portugal 2020 Competitiveness and Internationalization Operational Programme(POCI),reference POCI-01-0145-FEDER-030250 and PTDC/ASP-SIL/30250/2017-TOPDEVIL+1 种基金the R&D Unit Centre for Functional Ecology-Science for People and the Planet(CFE),with reference UIDB/04004/2020,financed by FCT/MCTES through national funds(PIDDAC)FCT/MCTES also funded L.P.S.with contract CEECIND/02064/2017。
文摘Providing nest-boxes as surrogate tree cavities can be of great importance to increase the breeding populations of cavity-nesting birds in managed forests.However,the exact placement of nest-boxes should be taken into consideration to enhance their occupancy according to species-specific preferences.In this study,we investigated which factors can better predict nest-box occupancy by the Great Tit(Parus major)in eucalypt plantations.We used generalised linear mixed-effects models to analyse the influence of topography,nest-box positioning,vegetation cover and landscape variables on three-year occupancy records from 80 newly provided nest-boxes.Non-random patterns of nest-box occupancy were found with respect to all categories except topography.Results suggest that Great Tits prefer to occupy high-placed nest-boxes,close to areas that can provide them with supplementary resources either within or in the vicinity of the stand(i.e.,trees other than eucalypts,riparian vegetation,and large patches of adjacent habitats).Overall,this study provides important recommendations for nest-box placement and spatial distribution in managed forests and enhances the potential of nest-box interventions as a biodiversity offset and management tool.
