Habitat loss and fragmentation of the wildlife species due to anthropogenic developments have been becoming serious issues in biological conservation. Alborz wild sheep, listed as threatened by IUCN, is distributed in...Habitat loss and fragmentation of the wildlife species due to anthropogenic developments have been becoming serious issues in biological conservation. Alborz wild sheep, listed as threatened by IUCN, is distributed in relatively small and isolated patches in an increasingly human dominated landscape in the north-central Iran and east of Tehran. We used maximum entropy modeling to identify habitat areas of the wild sheep, across Jajrud protected area and its neighbouring protected areas including varjin, lar, koohsefid and the surroundings. Regarding to seasonal variation of the species home range, winter, summer and multi seasonal (annual) habitats were predicted. To estimate habitat connectivity, we used models of connectivity based in electrical circuit theory. Applying core areas of multi season for connectivity analysis, movement pattern of the species was predicted and important connective areas for conservation were identified. Species distribution maps revealed that the summer and winter habitats were approximately occurred in similar areas. Distance to eco-guards’ post was the most important predictor for both habitat models of summer and winter. The annual model, which is a combination of summer and winter, shows that the largest suitable habitat patches are located in the north, south and west of the study area. Maximum current flow map demonstrates that the areas among patch pairs are covered in low current, reflecting low rates of the species dispersal. This map presented bottlenecks to the species movement across major roads and along extending human settlements. Cumulative current flow map displayed that current was highest in Jajrud north of Mamloo extending to the northern Jajrud. Overall, our study demonstrated a prediction of habitat suitability and connectivity for Alborz wild sheep in east of Tehran, which can be used to direct conservation endeavours dealing with maintenance of the wild sheep metapopulation dynamics.展开更多
Background:The European Kingfisher(Alcedo atthis)is a small plunge-diving bird,today considered a species of conservation concern in Europe given its rapid population decline observed across the continent.We implement...Background:The European Kingfisher(Alcedo atthis)is a small plunge-diving bird,today considered a species of conservation concern in Europe given its rapid population decline observed across the continent.We implemented a pilot study aimed at providing first data allowing to:(1)assess home range features of the European Kingfisher for populations with unevenly distributed feeding habitats;(2)define conservation implications for habitats exploited by such populations;and(3)evaluate possibilities for developing GPS tracking schemes dedicated to home range stud-ies for this species that could be possibly applied to other small plunge-diving birds.Methods:In 2018 and 2019,we equipped 16 breeding European Kingfishers sampled within the marshes of the Gironde Estuary(France),with miniaturized and waterproof GPS archival tags deployed with leg-loop harnesses(total equipment mass=1.4 g;average bird mass=40.18±1.12 g).Results:On average,we collected 35.31±6.66 locations usable for analyses,without a significant effect on bird body condition(n=13 tags retrieved).Data analyses highlighted rather limited home ranges exploited by birds(aver-age=2.50±0.55 ha),composed on average by 2.78±0.40 location nuclei.Our results also underscore:(1)a rather important home range fragmentation index(0.36±0.08);and(2)the use by birds of different types of small wetlands(wet ditches,small ponds or small waterholes),often exploited in addition to habitats encompassing nest locations.Conclusions:Our study reveals interesting GPS tracking possibilities for small plunge-diving birds such as the European Kingfisher.For this species,today classified as vulnerable in Europe,our results underline the importance of developing conservation and ecological restoration policies for wetland networks that would integrate small wet-lands particularly sensitive to global change.展开更多
The continuation of the isolated Amur tiger(Panthera tigris altaica)population living along the China-Russia border is facing serious challenges due to factors such as its small size(including 38 individuals)and canin...The continuation of the isolated Amur tiger(Panthera tigris altaica)population living along the China-Russia border is facing serious challenges due to factors such as its small size(including 38 individuals)and canine distemper virus(CDV).We use a population viability analysis metamodel,which consists of a traditional individual-based demographic model linked to an epidemiological model,to assess options for controlling the impact of negative factors through domestic dog management in protected areas,increasing connectivity to the neighboring large population(including more than 400 individuals),and habitat expansion.Without intervention,under inbreeding depression of 3.14,6.29,and 12.26 lethal equivalents,our metamodel predicted the extinction within 100 years is 64.4%,90.6%,and 99.8%,respectively.In addition,the simulation results showed that dog management or habitat expansion independently will not ensure tiger population viability for the next 100 years,and connectivity to the neighboring population would only keep the population size from rapidly declining.However,when the above three conservation scenarios are combined,even at the highest level of 12.26 lethal equivalents inbreeding depression,population size will not decline and the probability of extinction will be<5.8%.Our findings highlight that protecting the Amur tiger necessitates a multifaceted synergistic effort.Our key management recommendations for this population underline the importance of reducing CDV threats and expanding tiger occupancy to its former range in China,but re-establishing habitat connectivity to the neighboring population is an important long-term objective.展开更多
This study explores the differences of fish assemblages in three macrotidal estuaries of Man-gyeong River Estuary(MRE),Geum River Estuary(GRE),and Han River Esturay(HRE)with similar ranges of seasonal water temperatur...This study explores the differences of fish assemblages in three macrotidal estuaries of Man-gyeong River Estuary(MRE),Geum River Estuary(GRE),and Han River Esturay(HRE)with similar ranges of seasonal water temperature that are diked with different levels of disconnection from freshwater discharge.The distribution of major species in the three estuaries could generally be grouped into three distinctive patterns based on their cumulative distribution with respect to the salinity gradient.The MRE was geographically closer to the GRE than to the HRE,but the fish community of the MRE more closely resembled that of the HRE.Increased freshness of the water inside the dike and the limit of coastal fish to the river may have led to this result.The results provide clues to how enclosure patterns of estuarine waters could affect fish communities over a long-term period.In addition,the information may provide guidance for how a fish community may return once environmental conditions are restored.展开更多
文摘Habitat loss and fragmentation of the wildlife species due to anthropogenic developments have been becoming serious issues in biological conservation. Alborz wild sheep, listed as threatened by IUCN, is distributed in relatively small and isolated patches in an increasingly human dominated landscape in the north-central Iran and east of Tehran. We used maximum entropy modeling to identify habitat areas of the wild sheep, across Jajrud protected area and its neighbouring protected areas including varjin, lar, koohsefid and the surroundings. Regarding to seasonal variation of the species home range, winter, summer and multi seasonal (annual) habitats were predicted. To estimate habitat connectivity, we used models of connectivity based in electrical circuit theory. Applying core areas of multi season for connectivity analysis, movement pattern of the species was predicted and important connective areas for conservation were identified. Species distribution maps revealed that the summer and winter habitats were approximately occurred in similar areas. Distance to eco-guards’ post was the most important predictor for both habitat models of summer and winter. The annual model, which is a combination of summer and winter, shows that the largest suitable habitat patches are located in the north, south and west of the study area. Maximum current flow map demonstrates that the areas among patch pairs are covered in low current, reflecting low rates of the species dispersal. This map presented bottlenecks to the species movement across major roads and along extending human settlements. Cumulative current flow map displayed that current was highest in Jajrud north of Mamloo extending to the northern Jajrud. Overall, our study demonstrated a prediction of habitat suitability and connectivity for Alborz wild sheep in east of Tehran, which can be used to direct conservation endeavours dealing with maintenance of the wild sheep metapopulation dynamics.
基金financial support of the Département de la Charente-Maritime
文摘Background:The European Kingfisher(Alcedo atthis)is a small plunge-diving bird,today considered a species of conservation concern in Europe given its rapid population decline observed across the continent.We implemented a pilot study aimed at providing first data allowing to:(1)assess home range features of the European Kingfisher for populations with unevenly distributed feeding habitats;(2)define conservation implications for habitats exploited by such populations;and(3)evaluate possibilities for developing GPS tracking schemes dedicated to home range stud-ies for this species that could be possibly applied to other small plunge-diving birds.Methods:In 2018 and 2019,we equipped 16 breeding European Kingfishers sampled within the marshes of the Gironde Estuary(France),with miniaturized and waterproof GPS archival tags deployed with leg-loop harnesses(total equipment mass=1.4 g;average bird mass=40.18±1.12 g).Results:On average,we collected 35.31±6.66 locations usable for analyses,without a significant effect on bird body condition(n=13 tags retrieved).Data analyses highlighted rather limited home ranges exploited by birds(aver-age=2.50±0.55 ha),composed on average by 2.78±0.40 location nuclei.Our results also underscore:(1)a rather important home range fragmentation index(0.36±0.08);and(2)the use by birds of different types of small wetlands(wet ditches,small ponds or small waterholes),often exploited in addition to habitats encompassing nest locations.Conclusions:Our study reveals interesting GPS tracking possibilities for small plunge-diving birds such as the European Kingfisher.For this species,today classified as vulnerable in Europe,our results underline the importance of developing conservation and ecological restoration policies for wetland networks that would integrate small wet-lands particularly sensitive to global change.
基金This work was supported by the National Natural Science Foundation of China(31971539)the National Science and Technology Basic Resources Survey Program of China(2019FY101700)a scholarship from the China Scholarship Council(202106040062).
文摘The continuation of the isolated Amur tiger(Panthera tigris altaica)population living along the China-Russia border is facing serious challenges due to factors such as its small size(including 38 individuals)and canine distemper virus(CDV).We use a population viability analysis metamodel,which consists of a traditional individual-based demographic model linked to an epidemiological model,to assess options for controlling the impact of negative factors through domestic dog management in protected areas,increasing connectivity to the neighboring large population(including more than 400 individuals),and habitat expansion.Without intervention,under inbreeding depression of 3.14,6.29,and 12.26 lethal equivalents,our metamodel predicted the extinction within 100 years is 64.4%,90.6%,and 99.8%,respectively.In addition,the simulation results showed that dog management or habitat expansion independently will not ensure tiger population viability for the next 100 years,and connectivity to the neighboring population would only keep the population size from rapidly declining.However,when the above three conservation scenarios are combined,even at the highest level of 12.26 lethal equivalents inbreeding depression,population size will not decline and the probability of extinction will be<5.8%.Our findings highlight that protecting the Amur tiger necessitates a multifaceted synergistic effort.Our key management recommendations for this population underline the importance of reducing CDV threats and expanding tiger occupancy to its former range in China,but re-establishing habitat connectivity to the neighboring population is an important long-term objective.
基金This study was partly supported by Chung-nam National University to K-H.Choiproject PG50850 of the Korea Institute of Ocean Science and Technology(KIOST)to S.W.Hwang.
文摘This study explores the differences of fish assemblages in three macrotidal estuaries of Man-gyeong River Estuary(MRE),Geum River Estuary(GRE),and Han River Esturay(HRE)with similar ranges of seasonal water temperature that are diked with different levels of disconnection from freshwater discharge.The distribution of major species in the three estuaries could generally be grouped into three distinctive patterns based on their cumulative distribution with respect to the salinity gradient.The MRE was geographically closer to the GRE than to the HRE,but the fish community of the MRE more closely resembled that of the HRE.Increased freshness of the water inside the dike and the limit of coastal fish to the river may have led to this result.The results provide clues to how enclosure patterns of estuarine waters could affect fish communities over a long-term period.In addition,the information may provide guidance for how a fish community may return once environmental conditions are restored.