Linear infrastructures(e.g.,roads,railways,pipelines,and powerlines)pose a serious threat to wildlife,due to the risk of wildlife-vehicle collisions(roadkills).The placement of mitigation measures,such as crossing str...Linear infrastructures(e.g.,roads,railways,pipelines,and powerlines)pose a serious threat to wildlife,due to the risk of wildlife-vehicle collisions(roadkills).The placement of mitigation measures,such as crossing structures,should consider species’life cycles and ecological requirements.Such an assessment would require data collection over large areas,which may be possible by employing citizen science.In this study,we aimed to identify spatiotemporal trends of roadkill occurrence using citizen science data from one of the most urbanized and biodiversityrich regions of Italy.Temporal trends were analyzed using generalized additive models,while landscape patterns were assessed by identifying significant thresholds over land cover gradients,related to increases in relative roadkill abundance,by employing threshold indicator taxa analysis.Our approach recorded a total of 529 roadkills,including 33 different species,comprising 13 mammal,10 bird,6 reptile,and 2 amphibian species.Statistical analysis indicated significant temporal trends for the red fox,the European hedgehog,the stone marten and the European badger,with peaks in roadkill occurrence between the winter and spring months.Relative roadkill abundance increased mostly in landscapes with anthropogenic land cover classes,such as complex cultivations,orchards,or urban surfaces.Our results allowed us to develop a map of potential roadkill risk that could assist in planning the placement of mitigation measures.Citizen science contributions from highly populated areas allowed data collection over a large area and a dense road network,and also directly led to the evaluation of management decisional options.展开更多
With the extirpation of apex predators from many North American systems, coyotes Canis latrans have become the de facto top predator and are ubiquitous members of most ecosystems. Keystone predators aid in maintaining...With the extirpation of apex predators from many North American systems, coyotes Canis latrans have become the de facto top predator and are ubiquitous members of most ecosystems. Keystone predators aid in maintaining ecosystem function by regulating the mammal community through direct predation and instilling the landscape of fear, yet the value of coyotes regulating systems to this capacity is understudied and likely variable across environments. Since coyotes are common in the Midwestern United States, we utilized camera traps and occupancy analyses to as- sess their role in regulating the distribution of mammalian herbivores in a fragmented suburban ecosystem. Forest cover was a strong positive predictor of white-tailed deer Odocoileus virginianus detection, while coyote occurrence had a negative effect. Coyotes exerted a negative effect on squirrel （Sciurus spp.） and eastern cottontail rabbit Sylvilagus floridanus occurrence, while urban cover was a positive predictor for the prey species＇ occurrence. These results suggest all 3 species behaviorally avoid coyotes whereby deer seek denser forest cover and squirrels and cottontails mitigate risk by increasing use of urban areas. Although previous studies reveal limited influence of coyote on the rest of the carnivore guild in suburban systems, we suggest coyotes play an important role in regulating the herbivorous mammals and hence may provide similar eco- logical, benefits in urban/suburban forest fragments through trophic cascades. Furthermore, since hunting may not be allowed in urban and suburban habitats, coyotes might also serve as the pri- mary regulator of nuisance species occurring at high abundance such as white-tailed deer and squirrels.展开更多
文摘Linear infrastructures(e.g.,roads,railways,pipelines,and powerlines)pose a serious threat to wildlife,due to the risk of wildlife-vehicle collisions(roadkills).The placement of mitigation measures,such as crossing structures,should consider species’life cycles and ecological requirements.Such an assessment would require data collection over large areas,which may be possible by employing citizen science.In this study,we aimed to identify spatiotemporal trends of roadkill occurrence using citizen science data from one of the most urbanized and biodiversityrich regions of Italy.Temporal trends were analyzed using generalized additive models,while landscape patterns were assessed by identifying significant thresholds over land cover gradients,related to increases in relative roadkill abundance,by employing threshold indicator taxa analysis.Our approach recorded a total of 529 roadkills,including 33 different species,comprising 13 mammal,10 bird,6 reptile,and 2 amphibian species.Statistical analysis indicated significant temporal trends for the red fox,the European hedgehog,the stone marten and the European badger,with peaks in roadkill occurrence between the winter and spring months.Relative roadkill abundance increased mostly in landscapes with anthropogenic land cover classes,such as complex cultivations,orchards,or urban surfaces.Our results allowed us to develop a map of potential roadkill risk that could assist in planning the placement of mitigation measures.Citizen science contributions from highly populated areas allowed data collection over a large area and a dense road network,and also directly led to the evaluation of management decisional options.
文摘With the extirpation of apex predators from many North American systems, coyotes Canis latrans have become the de facto top predator and are ubiquitous members of most ecosystems. Keystone predators aid in maintaining ecosystem function by regulating the mammal community through direct predation and instilling the landscape of fear, yet the value of coyotes regulating systems to this capacity is understudied and likely variable across environments. Since coyotes are common in the Midwestern United States, we utilized camera traps and occupancy analyses to as- sess their role in regulating the distribution of mammalian herbivores in a fragmented suburban ecosystem. Forest cover was a strong positive predictor of white-tailed deer Odocoileus virginianus detection, while coyote occurrence had a negative effect. Coyotes exerted a negative effect on squirrel （Sciurus spp.） and eastern cottontail rabbit Sylvilagus floridanus occurrence, while urban cover was a positive predictor for the prey species＇ occurrence. These results suggest all 3 species behaviorally avoid coyotes whereby deer seek denser forest cover and squirrels and cottontails mitigate risk by increasing use of urban areas. Although previous studies reveal limited influence of coyote on the rest of the carnivore guild in suburban systems, we suggest coyotes play an important role in regulating the herbivorous mammals and hence may provide similar eco- logical, benefits in urban/suburban forest fragments through trophic cascades. Furthermore, since hunting may not be allowed in urban and suburban habitats, coyotes might also serve as the pri- mary regulator of nuisance species occurring at high abundance such as white-tailed deer and squirrels.
