Whether introduced into a completely novel habitat or slowly expanding their current range,the degree to which animals can effciently explore and navigate new environments can be key to survival,ultimately determining...Whether introduced into a completely novel habitat or slowly expanding their current range,the degree to which animals can effciently explore and navigate new environments can be key to survival,ultimately determining population establishment and colonization success.We tested whether spatial orientation and exploratory behavior are associated with non-native spread in free-living bank voles(Myodes glareolus,N=43)from a population accidentally introduced to Ireland a century ago.We measured spatial orientation and navigation in a radial arm maze,and behaviors associated to exploratory tendencies and risk-taking in repeated open-feld tests,at the expansion edge and in the source population.Bank voles at the expansion edge re-visited unrewarded arms of the maze more,waited longer before leaving it,took longer to start exploring both the radial arm maze and the open feld,and were more risk-averse compared to conspecifcs in the source population.Taken together,results suggest that for this small mammal under heavy predation pressure,a careful and thorough exploration strategy might be favored when expanding into novel environments.展开更多
Introduction:Bats are threatened by agricultural intensification,and although bat ecology in agricultural landscapes is in the focus of current research,the effects of interacting spatiotemporal factors on species-spe...Introduction:Bats are threatened by agricultural intensification,and although bat ecology in agricultural landscapes is in the focus of current research,the effects of interacting spatiotemporal factors on species-specific bat activity above farmland remain understudied.Our aim was to identify spatiotemporal factors and their interactions relevant for the activity of bat species above conventionally managed arable fields.Methods:We repeatedly monitored relative bat activity above open arable fields in Germany using acoustic monitoring.We used site-related biotic and abiotic factors and landscape characteristics across five spatial scales,their combinations,and interactions to identify those factors which best explain variation in bat activity.Results:Numerous interactions between landscape characteristics and the insect abundance affected bat activity above fields.For instance,Pipistrellus pipistrellus became more active with increasing insect abundance,but only above fields with a low proportion of woody vegetation cover in the surroundings.Additionally,the level of bat activity in summer depended on landscape characteristics.For example,the activity of Pipistrellus nathusii was relatively low in summer above fields that were surrounded by vegetation patches with a high degree of edge complexity(e.g.,hedgerow).However,the activity remained at a relatively high level and did not differ between seasons above fields that were surrounded by vegetation patches with a low degree of edge complexity(e.g.,roundly shaped forest patch).Conclusions:Our results revealed that landscape characteristics and their interactions with insect abundance affected bat activity above conventionally managed fields and highlighted the opportunistic foraging behavior of bats.To improve the conditions for bats in agricultural landscapes,we recommend re-establishing landscape heterogeneity to protect aquatic habitats and to increase arthropod availability.展开更多
Stopover niche utilization of birds during migration has not gained much attention so far,since the majority of the studies focuses on breeding or wintering areas.However,stopover sites are crucial for migratory birds...Stopover niche utilization of birds during migration has not gained much attention so far,since the majority of the studies focuses on breeding or wintering areas.However,stopover sites are crucial for migratory birds.They are often used by a multitude of species,which could lead to increased competition.In this work,we investigated niche use of 8 migratory and closely related Emberiza bunting species at a stopover site in Far East Russia,situated on the poorly studied East Asian flyway.We used bird ringing data to evaluate morphological similarity as well as niche overlap on the trophic,spatial,and temporal dimension.Bill morphology was used as a proxy for their trophic niche.We were able to prove that a majority of the species occupies well-defined stopover niches on at least one of the dimensions.Niche breadth and niche overlap differ between spring and autumn season with higher overlap found during spring.Morphological differences are mostly related to overall size and wing pointedness.The temporal dimension is most important for segregation among the studied species.Furthermore,all species seem to exhibit a rather strict and consistent phenological pattern.Their occurrence at the study site is highly correlated with their geographic origin and the length of their migration route.We assume that buntings are able to use available resources opportunistically during stopover,while trying to follow a precise schedule in order to avoid competition and to ensure individual fitness.展开更多
基金This study was made possible by funding from the German Science Foundation(DFG)supporting prior steps of the project(grant nr.430970462 to J.A.E.).
文摘Whether introduced into a completely novel habitat or slowly expanding their current range,the degree to which animals can effciently explore and navigate new environments can be key to survival,ultimately determining population establishment and colonization success.We tested whether spatial orientation and exploratory behavior are associated with non-native spread in free-living bank voles(Myodes glareolus,N=43)from a population accidentally introduced to Ireland a century ago.We measured spatial orientation and navigation in a radial arm maze,and behaviors associated to exploratory tendencies and risk-taking in repeated open-feld tests,at the expansion edge and in the source population.Bank voles at the expansion edge re-visited unrewarded arms of the maze more,waited longer before leaving it,took longer to start exploring both the radial arm maze and the open feld,and were more risk-averse compared to conspecifcs in the source population.Taken together,results suggest that for this small mammal under heavy predation pressure,a careful and thorough exploration strategy might be favored when expanding into novel environments.
文摘Introduction:Bats are threatened by agricultural intensification,and although bat ecology in agricultural landscapes is in the focus of current research,the effects of interacting spatiotemporal factors on species-specific bat activity above farmland remain understudied.Our aim was to identify spatiotemporal factors and their interactions relevant for the activity of bat species above conventionally managed arable fields.Methods:We repeatedly monitored relative bat activity above open arable fields in Germany using acoustic monitoring.We used site-related biotic and abiotic factors and landscape characteristics across five spatial scales,their combinations,and interactions to identify those factors which best explain variation in bat activity.Results:Numerous interactions between landscape characteristics and the insect abundance affected bat activity above fields.For instance,Pipistrellus pipistrellus became more active with increasing insect abundance,but only above fields with a low proportion of woody vegetation cover in the surroundings.Additionally,the level of bat activity in summer depended on landscape characteristics.For example,the activity of Pipistrellus nathusii was relatively low in summer above fields that were surrounded by vegetation patches with a high degree of edge complexity(e.g.,hedgerow).However,the activity remained at a relatively high level and did not differ between seasons above fields that were surrounded by vegetation patches with a low degree of edge complexity(e.g.,roundly shaped forest patch).Conclusions:Our results revealed that landscape characteristics and their interactions with insect abundance affected bat activity above conventionally managed fields and highlighted the opportunistic foraging behavior of bats.To improve the conditions for bats in agricultural landscapes,we recommend re-establishing landscape heterogeneity to protect aquatic habitats and to increase arthropod availability.
文摘Stopover niche utilization of birds during migration has not gained much attention so far,since the majority of the studies focuses on breeding or wintering areas.However,stopover sites are crucial for migratory birds.They are often used by a multitude of species,which could lead to increased competition.In this work,we investigated niche use of 8 migratory and closely related Emberiza bunting species at a stopover site in Far East Russia,situated on the poorly studied East Asian flyway.We used bird ringing data to evaluate morphological similarity as well as niche overlap on the trophic,spatial,and temporal dimension.Bill morphology was used as a proxy for their trophic niche.We were able to prove that a majority of the species occupies well-defined stopover niches on at least one of the dimensions.Niche breadth and niche overlap differ between spring and autumn season with higher overlap found during spring.Morphological differences are mostly related to overall size and wing pointedness.The temporal dimension is most important for segregation among the studied species.Furthermore,all species seem to exhibit a rather strict and consistent phenological pattern.Their occurrence at the study site is highly correlated with their geographic origin and the length of their migration route.We assume that buntings are able to use available resources opportunistically during stopover,while trying to follow a precise schedule in order to avoid competition and to ensure individual fitness.
