Mixed evidence for disturbance‐mediated apparent competition for declining caribou in western British Columbia, Canada

Journal of Wildlife Management, Год журнала: 2025, Номер unknown

Опубликована: Май 19, 2025

Abstract Understanding causal mechanisms of decline for species at risk is critical effective conservation. Caribou ( Rangifer tarandus ) face threats from habitat loss and degradation due to human activities, many caribou populations across Canada have experienced dramatic declines in recent decades. Disturbance‐mediated apparent competition (DMAC) has been implicated these declines, but its generality questioned, particularly low‐productivity ranges. The DMAC hypothesis leads the following predictions: 1) a vegetation productivity pulse after disturbance, 2) primary ungulate prey attraction disturbed areas, 3) predator 4) increased predation overlapping use with predators. We tested predictions declining Itcha‐Ilgachuz population, located Chilcotin Plateau region west‐central British Columbia, Canada. used remotely sensed index examine recovery patterns disturbance camera traps Bayesian mixed effects negative binomial regression models estimate responses prey, predator, relative abundance landscape disturbances <40 years old, interacting species, other features. identified harvested burnt forest patches, overall was lower than ranges where occurs. Primary moose Alces alces mule deer Odocoileus hemionus ), showed strong positive areas weak forest. For predators, wolves Canis lupus black bears Ursus americanus grizzly arctos were positively associated while coyotes latrans lynx Lynx canadensis more strongly snowshoe hare Lepus wolverines Gulo gulo not any focal species. Wolves, bears, coyotes, responded burned areas. did reduced forests or burns, potentially increasing their overlap Overall, we found support stronger evidence pathway mediated by fire, rather harvest. recommend further research action on wildfire management this including monitoring population trends response management. Our results emphasize context‐dependency underscore need population‐specific knowledge effectively conserve threatened

Язык: Английский

Disturbance‐mediated changes to boreal mammal spatial networks in industrializing landscapes

Ecological Applications, Год журнала: 2024, Номер 34(6)

Опубликована: Июнь 26, 2024

Compound effects of anthropogenic disturbances on wildlife emerge through a complex network direct responses and species interactions. Land-use changes driven by energy forestry industries are known to disrupt predator-prey dynamics in boreal ecosystems, yet how these disturbance propagate across mammal communities remains uncertain. Using structural equation modeling, we tested disturbance-mediated pathways governing the spatial structure multipredator multiprey networks landscape-scale gradient within Canada's Athabasca oil sands region. Linear had pervasive effects, increasing site use for all focal species, except black bears threatened caribou, at least one landscape. Conversely, block (polygonal) were negative but less common. Indirect widespread mediated caribou avoidance wolves, tracking primary prey subordinate predators, intraguild dependencies among predators large prey. Context-dependent linear most common landscape with intermediate disturbance. Our research suggests that industrial directly affect suite mammals altering forage availability movement, leading indirect range interacting prey, including keystone snowshoe hare. The complexity network-level reinforces calls increased investment addressing habitat degradation as root cause declines broader ecosystem change.

Язык: Английский