Based on mass balance theory and IsoSource program,stable carbon and nitrogen isotopic ratios revealed that small mammals (plateau pika,root vole and plateau zokor) contributed 26.8% and 27.0% and 29.2% to alpine weas...Based on mass balance theory and IsoSource program,stable carbon and nitrogen isotopic ratios revealed that small mammals (plateau pika,root vole and plateau zokor) contributed 26.8% and 27.0% and 29.2% to alpine weasel,steppe polecat and upland buzzard of carnivores as food respectively;adult passerine birds contributed 22.3%,47.7% and 69.1%,with hatchlings contributing 50.9%,25.6% and 1.70% to each respectively.δ 13 C values plotted against δ 15 N indicated significant partitioning in two-dimensional space among the three carnivores.It was reasonable to propose a food resource partitioning among alpine weasel,steppe polecat and upland buzzard,which partially revealed their co-existence mechanisms.展开更多
Climate change,habitat loss and fragmentation are major threats for populations and a challenge for individual behavior,interactions and survival.Predator-prey interactions are modified by climate processes.In the nor...Climate change,habitat loss and fragmentation are major threats for populations and a challenge for individual behavior,interactions and survival.Predator-prey interactions are modified by climate processes.In the northern latitudes,strong seasonality is changing and the main predicted feature is shortening and instability of winter.Vole populations in the boreal Fennoscandia exhibit multiannual cycles.High amplitude peak numbers of voles and dramatic population lows alternate in 3-5-year cycles shortening from North to South.One key factor,or driver,promoting the population crash and causing extreme extended lows,is suggested to be predation by the least weasel.We review the arms race between prey voles and weasels through the multiannual density fluctuation,affected by climate change,and especially the changes in the duration and stability of snow cover.For ground-dwelling small mammals,snow provides thermoregulation and shelter for nest sites,and helps them hide from predators.Predicted increases in the instability of winter forms a major challenge for species with coat color change between brown summer camouflage and white winter coat.One of these is the least weasel,Mustela nivalis nivalis.Increased vulnerability of wrong-colored weasels to predation affects vole populations and may have dramatic effects on vole dynamics.It may have cascading effects on other small rodent-predator interactions and even on plant-animal interactions and forest dynamics.展开更多
文摘Based on mass balance theory and IsoSource program,stable carbon and nitrogen isotopic ratios revealed that small mammals (plateau pika,root vole and plateau zokor) contributed 26.8% and 27.0% and 29.2% to alpine weasel,steppe polecat and upland buzzard of carnivores as food respectively;adult passerine birds contributed 22.3%,47.7% and 69.1%,with hatchlings contributing 50.9%,25.6% and 1.70% to each respectively.δ 13 C values plotted against δ 15 N indicated significant partitioning in two-dimensional space among the three carnivores.It was reasonable to propose a food resource partitioning among alpine weasel,steppe polecat and upland buzzard,which partially revealed their co-existence mechanisms.
文摘Climate change,habitat loss and fragmentation are major threats for populations and a challenge for individual behavior,interactions and survival.Predator-prey interactions are modified by climate processes.In the northern latitudes,strong seasonality is changing and the main predicted feature is shortening and instability of winter.Vole populations in the boreal Fennoscandia exhibit multiannual cycles.High amplitude peak numbers of voles and dramatic population lows alternate in 3-5-year cycles shortening from North to South.One key factor,or driver,promoting the population crash and causing extreme extended lows,is suggested to be predation by the least weasel.We review the arms race between prey voles and weasels through the multiannual density fluctuation,affected by climate change,and especially the changes in the duration and stability of snow cover.For ground-dwelling small mammals,snow provides thermoregulation and shelter for nest sites,and helps them hide from predators.Predicted increases in the instability of winter forms a major challenge for species with coat color change between brown summer camouflage and white winter coat.One of these is the least weasel,Mustela nivalis nivalis.Increased vulnerability of wrong-colored weasels to predation affects vole populations and may have dramatic effects on vole dynamics.It may have cascading effects on other small rodent-predator interactions and even on plant-animal interactions and forest dynamics.
