Habitat Management in the Yukon Winter Range of the Little Rancheria Caribou Herd J.Z. Adamczewski, R.F. Florkiewicz and V. Loewen Habitat Management in the Yukon Winter Range of the Little Rancheria Caribou Herd TR-03-02 Acknowledgements Many biologists and students contributed to the biological studies summarized in the companion report on Rancheria caribou habitat use and ecology (Florkiewicz et al. 2003). They are listed in that report and we thank them again, as their work built the biological foundation on which this report is based. We would also like to thank Shawn Francis, Bob Wynes, Simon Dyer, Brad Stelfox, Robert Anderson and Elston Dzus for their work, reports, and ideas on caribou conservation and management. Special thanks to Norm MacLean and his British Columbia colleagues Rick Marshall, Tom Smith and Mark Williams for working with us on management of this caribou herd and for providing their radio-collar data. Jean Carey was a patient and thoughtful technical editor for this report. We greatly appreciate the peer reviews provided by Sue Kemmett, Norm MacLean, Rick Ward, Len Mychasiw, and Debbie Cichowski. ©2003 Department of Environment, Government of the Yukon You may use the information in this report for education or information purposes. If you want to use any portion of this report in scientific publications, you must have permission in writing from the Department of Environment, Fish and Wildlife Branch, Government of Yukon, Box 2703, Whitehorse, Yukon Territory Y1A 2C6 Rancheria caribou habitat management, Adamczewski, Florkiewicz & Loewen, 2003 page 1 Habitat Management in the Yukon Winter Range of the Little Rancheria Caribou Herd J.Z. Adamczewski, R.F. Florkiewicz and V. Loewen ____________________________________________ Director, Fish and Wildlife Branch ____________________________________________ Chief, Habitat and Regional Management Executive Summary was 50% or greater, the population was Woodland caribou (Rangifer tarandus likely to be declining at 1–3% annually, caribou) ranges have shrunk substantially even with little or no hunting. Threshold across North America due to the complex levels limiting the footprint in caribou range effects of human-caused habitat changes. As have been proposed as a management option a result, COSEWIC1 listed nearly all for the Yukon. Management guidelines for woodland caribou populations in Canada as caribou ranges in British Columbia and either Threatened or of Special Concern in Ontario focus on protecting critical caribou May 2002. The Little Rancheria Herd habitat from development and access, and (LRH) of caribou, which numbered about allow carefully managed development in 1,000 in 1999, has a lowland forested winter less sensitive caribou range. range with some merchantable pine and Three management zones in the Yukon spruce stands just west of Watson Lake, LRH winter range were identified in the Yukon. Timber harvest in this range has to 1990s based first on reconnaissance surveys date (2003) been limited but the potential for and later confirmed by radio-collar habitat fragmentation is high. In this report locations: a heavily used core, a surrounding we develop a long-term approach to habitat extended range, and a migration corridor. management of the Yukon LRH winter Although just 3.6% of the land-base had range, based on the herd’s habitat use and been cut for timber by 2002, the ecology, together with studies and development footprint in the LRH Yukon management of woodland caribou winter range was 16% overall, with 18% in elsewhere. the core, 18% in the extended range, and 5% The direct and indirect effects of in the migration zone. development on woodland caribou include: Like most Yukon caribou herds, the • loss of fragile, slow-growing lichens, the LRH is hunted. The estimated annual • primary caribou winter forage, harvest rate averaged 5% from 1992 to • avoidance of disturbed areas, 2002. To enable continued hunting of this particularly those with heavy traffic, herd, and to allow for periodic range losses • increased hunter access and harvest, to fire, development in this winter range must be kept at levels well below the 50% • collisions with vehicles, footprint values linked to serious declines in • increased access to remote caribou Alberta. range for predators, primarily wolves, and • The suggested management approach for improved habitat suitability for other the LRH Yukon winter range is based on • ungulates like moose. Where these British Columbia models, Alberta studies, other prey sustain elevated wolf numbers, and recent reports proposing thresholds for caribou numbers often decline. development footprint in caribou range. The Alberta studies showed that caribou were main points of the approach are: more likely to be killed by wolves in areas • withdraw the core winter range from within 250 m of all recent cut-blocks and further logging or development, other developments, and that caribou used • establish a connected reserve network these areas much less than undisturbed of high-quality habitat in the extended range forests. The development “footprint” was and migration zone, and defined as the proportion of the land-base • establish maximum development within such avoidance zones. Where the footprint values of 30% in the extended development footprint in a caribou range range and 25% in the migration zone. 1 COSEWIC - Committee On the Status of Endangered Wildlife in Canada Rancheria caribou habitat management, Adamczewski, Florkiewicz & Loewen, 2003 Page 1 Table of Contents Page 1 Executive Summary Page 2 Table of Contents Page 3 List of Figures and List of Tables Page 4 Status and management of woodland caribou in Canada and Yukon Status of woodland caribou in Canada Status and management of woodland caribou in northern BC and Yukon Page 5 Direct and indirect effects of development on woodland caribou Loss of terrestrial and arboreal lichens Loss of forest cover and avoidance of disturbed forests Increased hunter access and harvest Collisions with vehicles Increased predator access and higher predation risk Altered predator-prey balances leading to caribou declines Population ecology linked to development footprint Natural habitat alterations, including fire Synthesis – woodland caribou and development Page 9 Management of woodland caribou ranges – examples from Ontario, Alberta and British Columbia Ontario Alberta British Columbia Synthesis – management of caribou ranges in Ontario, Alberta and BC Page 11 Little Rancheria Herd ecology and habitat use Population ecology Hunting and other mortality sources Seasonal range use Changes in LRH range use over time Habitat use and habitat quality Page 14 Management of LRH Yukon winter range and risk evaluation Management status of the LRH winter range Proposed approach to LRH caribou range management Page 23 References Page 28 Appendix 1. Management recommendations for Little Rancheria Caribou winter range and forestry, 1996. Page 2 Rancheria caribou habitat management, Adamczewski, Florkiewicz & Loewen, 2003 List of Figures Page 6 Figure 1. Year-round (beige) and Yukon winter range (orange) of the Little Rancheria Herd of woodland caribou in British Columbia and Yukon. Boundaries of the BC portion of the LRH winter range were under review in 2003 (M. Domazet, B.C. Min. Sustainable Resource Management, Smithers, personal communication 2003) (from Florkiewicz et al. 2003). Page 18 Figure 2. Distribution of radio-collared caribou locations in winter in three management zones of the Yukon Little Rancheria Herd winter range, 1996–1999 (from Florkiewicz et al. 2003). Page 19 Figure 3. Habitat quality map for the Yukon Little Rancheria Herd winter range(from Florkiewicz et al. 2003). Page 20 Figure 4. Predicted habitat quality in areas north and west of the main Yukon winter range of the Little Rancheria Herd. Page 21 Figure 5. Overlap of Liard Timber Harvest Agreement (THA) with Yukon winter range of the Little Rancheria Herd. Page 22 Figure 6. Development footprint (all developed areas plus a 250m buffer) in November 2001 in the Yukon winter range of the Little Rancheria Herd. Page 23 Figure 7. Core winter range and surrounding connected network of high-quality habitat in the Yukon winter range of the Little Rancheria Herd. List of Tables Page 12 Table 1. October composition counts of the Little Rancheria Caribou Herd. Page 12 Table 2. Estimated average annual hunter kills of LRH caribou in BC and Yukon, l992– 2002. Page 3 Rancheria caribou habitat management, Adamczewski, Florkiewicz & Loewen, 2003 Status and management of tracts of old forest with abundant slow- woodland caribou in Canada growing lichens and relatively little use by and Yukon other hoofed mammals. As these forest tracts are reduced in size, made more accessible to predators and hunters, and Status of woodland caribou in converted to younger stands attractive to Canada other hoofed mammals, their capacity to The North American range of woodland support caribou erodes. caribou has shrunk substantially since settlement by Europeans (Bergerud 1974, Status and management of woodland Edmonds 1991). In May 2002, boreal eco- caribou in northern BC and Yukon type populations were listed as Threatened Ranges of the northern caribou eco-type by COSEWIC over a large National in British Columbia have to date been less Ecological Area (NEA) that includes impacted (Seip and Cichowski 1996) than Northwest Territories, British Columbia, Alberta’s caribou ranges (see Dzus 2001) Alberta, Saskatchewan, Manitoba, Ontario, because development