A continental scale trophic cascade from wolves through coyotes to foxes

摘要: Summary 1. Top-down processes, via the direct and indirect effects of interspecific competitive killing (no consumption kill) or intraguild predation (consumption kill), can potentially influence spatial distribution terrestrial predators, but few studies have demonstrated phenomenon at a continental scale. 2. For example, in North America, grey wolves Canis lupus are known to kill coyotes latrans, coyotes, turn, may foxes Vulpes spp., these interactions large scales unknown. 3. Here, we analyse fur return data across eight jurisdictions America test whether presence absence has caused continent-wide shift coyote red fox vulpes density. 4. Our results support existence scale cascade whereby outnumber areas where been extirpated by humans, whereas present. However, for distance up 200 km on edge wolf distribution, there is transition zone top-down control weakened, possibly due rapid dispersal reinvasion capabilities into sporadically distributed low densities. 5. implications understanding how restoration populations could affect co-occurring predators prey. We conclude that carnivores need occupy continuous facilitate among-carnivore cascades small not be indicative mesopredator control.