Little Terns Sternula albifrons are estuarine birds extensively using increasingly urbanized coastal areas.Given the increased exposure of these ecosystems to anthropogenic activities,it is crucial to study the ecolog...Little Terns Sternula albifrons are estuarine birds extensively using increasingly urbanized coastal areas.Given the increased exposure of these ecosystems to anthropogenic activities,it is crucial to study the ecology of this species and interactions with human stressors to establish management measures.We collected regurgitates(n=182)and blood samples(n=48)to study Little Terns’diet,health condition and isotopic niche,and individually tracked breeding adults(n=9,during 2021 and 2022)at 2 sandy beaches 21 km apart and located within Ria Formosa Natural Park,Algarve,Portugal.Although both areas are adjacent to foraging coastal marine areas and an estuarine lagoon system with saltpans,they differ in human disturbance.We also compared breeding success and adult health measures between these 2 colonies.The main prey for both populations were Sand Smelts Atherina spp.and Gobies Pomatoschistus spp.,and no differences in δ^(13)C and δ^(15)N stable isotopic values between colonies were found.Tracking data revealed that individuals foraged in the surroundings of their breeding colonies.Entrance Channels and Ocean were the most frequently used habitats for foraging by individuals from the less disturbed colony.Adults from the more disturbed colony foraged mostly in Entrance Channels.Overall,all individuals tended to forage during daytime.There were no differences in health measures of individuals between colonies,though breeding success at the most disturbed colony was comparably lower.It is important to protect both breeding areas and adjacent foraging habitats for Little Terns,particularly given the expected increasing pressure from human activities on coastal areas worldwide.展开更多
Natural native forests are rapidly being replaced by anthropogenic forests often with a strong presence of invasive alien plant species.Eucalypt species are widely planted worldwide,with Eucalyptus globulus plantation...Natural native forests are rapidly being replaced by anthropogenic forests often with a strong presence of invasive alien plant species.Eucalypt species are widely planted worldwide,with Eucalyptus globulus plantations being par-ticularly expressive in Portugal.Poor forestry practices often lead to the associated expansion of invasive species,such as Acacia dealbata.However,we still know relatively little about the functioning of anthropogenic forests,such as seed and pollen dispersal services.Here,we compared bird abundance and richness and the seed and pollen dispersal networks in both forest types.Anthropogenic forests presented lower bird abundance,and smaller,more simplified,and more random(abundance-based)seed dispersal services than those of natural forests.Interestingly,the pollen dispersal network was more similar than the seed dispersal network for both forest types and domi-nated by opportunistic and neutral processes,given the absence of specialized nectarivorous.The proportion of birds transporting seeds decreased,while those carrying pollen significantly increased in the anthropogenic forest compared to the native forest.Our work highlights the impact of anthropogenic forests on bird abundance,with consequences for seed dispersal services and forest regeneration.展开更多
基金financial and logistic support for fieldwork campaigns,GPS tracking devices and laboratory analysis from the project LIFE Ilhas Barreira project(LIFE18 NAT/PT/000927)funding provided by Foundation for Science and Technology,I.P.(FCT)to MARE(UIDB/MAR/04292/2020,https://doi.org/10.54499/UIDB/04292/2020 and UIDP/04292/2020,https://doi.org/10.54499/UIDP/04292/2020)+1 种基金the Associate Laboratory ARNET(LA/P/0069/2020,https://doi.org/10.54499/LA/P/0069/2020)supported by FCT doctoral fellowships(10.54499/2020.07495.BD,SFRH/BD/145827/2019)。
文摘Little Terns Sternula albifrons are estuarine birds extensively using increasingly urbanized coastal areas.Given the increased exposure of these ecosystems to anthropogenic activities,it is crucial to study the ecology of this species and interactions with human stressors to establish management measures.We collected regurgitates(n=182)and blood samples(n=48)to study Little Terns’diet,health condition and isotopic niche,and individually tracked breeding adults(n=9,during 2021 and 2022)at 2 sandy beaches 21 km apart and located within Ria Formosa Natural Park,Algarve,Portugal.Although both areas are adjacent to foraging coastal marine areas and an estuarine lagoon system with saltpans,they differ in human disturbance.We also compared breeding success and adult health measures between these 2 colonies.The main prey for both populations were Sand Smelts Atherina spp.and Gobies Pomatoschistus spp.,and no differences in δ^(13)C and δ^(15)N stable isotopic values between colonies were found.Tracking data revealed that individuals foraged in the surroundings of their breeding colonies.Entrance Channels and Ocean were the most frequently used habitats for foraging by individuals from the less disturbed colony.Adults from the more disturbed colony foraged mostly in Entrance Channels.Overall,all individuals tended to forage during daytime.There were no differences in health measures of individuals between colonies,though breeding success at the most disturbed colony was comparably lower.It is important to protect both breeding areas and adjacent foraging habitats for Little Terns,particularly given the expected increasing pressure from human activities on coastal areas worldwide.
基金support from the Portuguese Foundation for Science and Technology(FCT/MEC)via the grant SFRH/BD/77746/2011 and the individual research contract CEECIND/02064/2017/CP1423/CP1645/CT0009(https://doi.org/10.54499/CEECIND/02064/2017/CP1423/CP1645/CT0009)funded by(FCT/MEC)through grant UIDB/04004/2020.
文摘Natural native forests are rapidly being replaced by anthropogenic forests often with a strong presence of invasive alien plant species.Eucalypt species are widely planted worldwide,with Eucalyptus globulus plantations being par-ticularly expressive in Portugal.Poor forestry practices often lead to the associated expansion of invasive species,such as Acacia dealbata.However,we still know relatively little about the functioning of anthropogenic forests,such as seed and pollen dispersal services.Here,we compared bird abundance and richness and the seed and pollen dispersal networks in both forest types.Anthropogenic forests presented lower bird abundance,and smaller,more simplified,and more random(abundance-based)seed dispersal services than those of natural forests.Interestingly,the pollen dispersal network was more similar than the seed dispersal network for both forest types and domi-nated by opportunistic and neutral processes,given the absence of specialized nectarivorous.The proportion of birds transporting seeds decreased,while those carrying pollen significantly increased in the anthropogenic forest compared to the native forest.Our work highlights the impact of anthropogenic forests on bird abundance,with consequences for seed dispersal services and forest regeneration.
