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Use of adaptive management to mitigate risk of predation for woodland caribou in north-central British Columbia
Wildlife Infometrics Inc.
Woodland caribou (Rangifer tarandus caribou) in the Southern Mountain National Ecological Area were designated 'threatened' by COSEWIC in 2002, were added to the Species at Risk Act Schedule 1, and are a species at risk under the Forest and Range Practices Act in BC. Caribou are also commonly considered to be a leading indicator of biodiversity and ecosystem health in the boreal and sub-boreal forests (e.g., see ENGO programs such as Caribou Nation , Grey Ghosts , and Staring at Extinction ). In the late 1970s, the BC government sensed potential mismanagement of caribou with an apparent decline in populations and annual harvests exceeding 1,500 animals (McGregor 1985). After curtailing hunting, caribou populations continued to decline and now, despite the current legal status, the rate of decline indicates extirpation for many herds in a matter of decades (Wittmer 2004). The common denominator in this decline was considered by Messier et al. (2004) to be increased ungulate (other than caribou) populations that lead to increased numbers of predators and, hence, increased predation on caribou. Under those conditions caribou apparently suffer more incidental predation from wolves than would otherwise occur (Begerud 1983, Seip 1992, Racey et al. 1999). The increased mortality is exacerbated because caribou are possibly more susceptible to wolf predation than other ungulates (Seip 1991, Seip 1992, Thomas 1995). Increases in non-caribou ungulate populations (e.g., moose, deer, and elk) have been related to the abundance of young seral forests resulting from logging (Hatter 1950, Wallmo 1969, Spalding 1990, 1992, Rempel et al. 1997, Rettie and Messier 1998). Roads and other linear corridors may also benefit predator search rates and allow predator?s access to caribou in places that would otherwise be inaccessible (Jalkotzy et al. 1997; Bradshaw et al. 1997, James and Stuart-Smith 2000, Dyer et al. 2001). Corrective measures to reverse the decline of caribou therefore must involve predation mitigation either by managing early seral forest conditions, roads and linear corridors, non-caribou ungulates, predators, or a combination of these. There is little to no evidence of the success of these mitigation techniques but some research has led to the general conclusion that mitigating predation may be able to stabilize caribou populations (Seip 1992). Specific projects have focused on managing wolves directly (Elliot 1985, Janz 1989, Youds and Roorda 2001). Based on this information Recovery Implementation Groups (RIGs) consider that, where recovery of caribou can be shown to be biologically feasible through habitat management, management of predation will still likely be required in the short-term while habitat is being restored (MCTAC 2003, Seip 2005, BCTAC In Prep. , McNay et al. In Prep. ). This supposition is not new but the actual importance of non-caribou ungulates and efficacy of predation mitigation techniques remains largely untested and unknown. Provided there are places where predation mitigation can support caribou recovery, the efficacy of managing predation risk is therefore circumstantial and anecdotal. We propose a science-based comparison of predation mitigation using a combination of Habitat Supply Modeling (HSM) and adaptive management. On the basis of previous studies from radio-collared caribou, moose, and wolves in three caribou herd areas, we are able to opportunistically compare efficacy of recent predation mitigation activities in an adaptive management framework. Regulated wolf trapping has occurred and is continuing in one caribou herd area while an enhanced moose harvest has been planned and will be initiated this year in another caribou herd area. The third caribou herd area will be used as a spatial control. We can also use a HSM (Caribou Habitat Assessment and Supply Estimator ? CHASE; McNay et al. 2003) developed under previous Forest Science Program funding to guide adaptation of predation mitigation a ...
Report Number
Executive summary
Abundance and Distribution of Woodland Caribou in the Wolverine, Chase, and Scott Recovery Plan Areas
Annual Report

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