Spatio-temporal Niche Differentiation Of Four Carnivora Species And The Effects Of Human Interference

Species coexistence is a hot topic in animal ecology and community ecology research.It helps to understand how species allocate resources in an ecosystem and achieve long-term stable coexistence.Differentiation of temporal and spatial niches is an important mechanism for achieving coexistence among species in the same domain.Carnivorous animals,as top predators in ecosystems,play an important role in maintaining the structural stability and biodiversity of communities.However,with the further development of human,a series of problems such as habitat fragmentation and islandization have compressed the living space of carnivorous animals and subtly affected their temporal and spatial distribution,threatening their long-term survival and reproduction.Understanding the differentiation of temporal and spatial ecological niches among carnivorous animals with co-distribution and the impact of human interference on them can deepen our understanding of species coexistence mechanisms and promote the protection of carnivorous animals.From November 2019 to August 2022,this study investigated the differentiation of temporal and spatial ecological niches of four species of carnivorous animals in the Gabogou area of Yajiang County,Garze Tibetan Autonomous Prefecture.The activity rhythms and spatial distribution data of the target species were obtained by monitoring 63 500m×500m infrared camera sites.The results are as follows:(1)The four carnivorous animals leopard cat(Prionailurus bengalensis),red fox(Vulpes vulpes),yellow-throated marten(Martes flavigula)and wolf(Canis lupus)showed high activity intensity in the cold season and low activity intensity in the warm season.In terms of daily activity rhythms,leopard cats and red foxes are nocturnal,with activity peaks before sunrise and after sunset;yellow-throated martens are diurnal,maintaining a relatively high level of activity during the day;wolves are crepuscular,with activity peaks after sunrise and before sunset.There was no significant difference in daily activity rhythms between the four carnivorous animals in the cold and warm seasons.The overlap index of daily activity rhythms showed that leopard cats and red foxes had a high degree of overlap,indicating significant interspecific competition in their temporal niche.Yellow-throated martens had a highly differentiated temporal niche compared to the other three species.Leopard cats and wolves,as well as red foxes and wolves,had medium degree of overlap in their nocturnal daily activity rhythms,but their activity peaks were significantly differentiated.(2)The linear regression results show that different types of human interference have different effects on the temporal niche of four carnivorous animals.Both the yellow-throated marten and the wolf increase their nocturnal activity in the presence of human landscapes and interference,while the leopard cat is only sensitive to human interference.However,neither type of human interference has a significant effect on the activity rhythm of the red fox.(3)The ecological niche width of the four carnivorous animals at the altitude dimension was different,with leopard cats having the widest ecological niche and wolves the narrowest.The altitude distribution of leopard cats overlapped with that of red foxes,leopard cats with yellow-throated martens,and red foxes with yellow-throated martens,while wolves had a higher degree of differentiation from the other three species in the altitude dimension.In terms of vegetation type dimension,the ecological niche width of yellow-throated martens was the widest,while that of red foxes was the narrowest.The overlap index of leopard cats and yellow-throated martens,as well as yellow-throated martens and wolves,was high in the vegetation type dimension.The degree of spatial ecological niche differentiation between the other two pairs of species was high.The spatial coexistence relationship between each pair of species showed that leopard cats and red foxes,as well as red foxes and wolves,tended to avoid each other spatially,while leopard cats and yellow-throated martens,as well as leopard cats and wolves,and yellow-throated martens and wolves tended to overlap spatially.(4)The results of the occupancy modeling analysis indicate that different environmental factors influence the spatial distribution of carnivores.Leopard cats are more easily found at sites with steeper slopes and closer to roads,while they are less likely to be found in areas with higher human presence or in alpine meadows and deciduous broadleaf forests.Similarly,red foxes tend to appear in mixed coniferous and broadleaf forests,deciduous broadleaf shrubs,and deciduous broadleaf forests,but are less likely to be found in oak forests at high altitudes or in areas with high elevation.Yellow-throated martens are more commonly found in areas with high predation interference,but are less likely to be found in coniferous or deciduous broadleaf forests.On the other hand,wolves are often found in higher altitude areas,as well as in coniferous and deciduous broadleaf shrubs and forests,but are less frequently found on steep slopes or in oak forests at high altitudes.Interestingly,it was found that temperature is negatively correlated with the detection rate of all four carnivores,indicating that the lower the temperature,the higher the activity frequency of the target species.The results of this study show that the four carnivorous animals exhibit a certain level of differentiation in their spatiotemporal niches,which promotes their long-term coexistence in the study area.However,human interference activities have compressed the living space of these target species,leading to unfavorable effects on their survival.