Canadian Journal of Zoology Bighorn sheep winter habitat selection and seasonal movements in an area of active coal mining Journal: Canadian Journal of Zoology Manuscript ID cjz-2016-0069.R1 Manuscript Type: Article Date Submitted by the Author: 29-Jun-2016 Complete List of Authors: Poole, Kim; Aurora Wildlife Research Serrouya, Robert; University of Alberta, Department of Biological Sciences Teske, Irene; British Columbia Ministry of Forests, Lands and Natural Resource OperationsDraft Podrasky, Kevin; Teck Coal Limited bighorn sheep, British Columbia, coal mining, habitat selection, Ovis Keyword: canadensis, reclamation, winter range https://mc06.manuscriptcentral.com/cjz-pubs Page 1 of 46 Canadian Journal of Zoology 13 July 2016 Kim G. Poole Aurora Wildlife Research 1918 Shannon Point Road, Nelson, BC, V1L 6K1, Canada Tele. (250) 825-4063 e-mail: [email protected] Bighorn sheep winter habitat selection and seasonal movements in an area of active coal mining Kim G. Poole, Rob Serrouya, Irene E. Teske, and Kevin Podrasky K.G. Poole , Aurora Wildlife Research, 1918 Shannon Point Road, Nelson, BC V1L 6K1, Canada [email protected] R. Serrouya , Department of Biological Sciences,Draft University of Alberta, Edmonton, AB T6G 2E9, Canada [email protected] I. Teske , Ministry of Forests, Lands and Natural Resource Operations, Fish, Wildlife and Habitat Section, 205 Industrial Road G., Cranbrook, BC V1C 7G5, Canada [email protected] K. Podrasky , Teck Coal Limited, P.O. Box 2003, Sparwood, BC V0B 2G0, Canada [email protected] https://mc06.manuscriptcentral.com/cjz-pubs Canadian Journal of Zoology Page 2 of 46 2 Bighorn sheep winter habitat selection and seasonal movements in an area of active coal mining K.G. Poole, R. Serrouya, I.E. Teske, and K. Podrasky Abstract: Winter is an important period for most mountain ungulates due to limited availability of preferred forage and costs associated with travel through deep snow. We examined winter habitat selection by Rocky Mountain bighorn sheep ( Ovis canadensis canadensis (Shaw, 1804)) where 4 large, open-pit coal mines are in operation. Sheep in this area generally winter at high elevation on windswept, south-facing native grasslands. We used GPS collars and Resource Selection Function analysis to examine movements and habitat selection. Most (79%) of the sheep were migratory and fidelity to winter ranges was high (88%). Sheep showed low use (~10–20%) of mine areas between November and April, followed by increased use peaking at 60–65% in September-October. Wintering sheep were positively associated with highDraft elevations, closeness to escape terrain, and warmer aspects. High-elevation, native grasslands were the highest ranked cover class. Most sheep that used mine areas during winter used reclaimed habitats, primarily reclaimed spoils and pits. Primary winter ranges comprised 4.3% of merged sheep range, emphasizing the limited amount of occupied winter ranges within the landscape. Disturbance to native winter range resulting from development should be minimized or be conducted in a manner that effectively manages and/or mitigates the impacts. Key words: bighorn sheep, British Columbia, coal mining, habitat selection, Ovis canadensis , reclamation, winter range https://mc06.manuscriptcentral.com/cjz-pubs Page 3 of 46 Canadian Journal of Zoology 3 Introduction Most mountain ungulates exhibit complex spatial and temporal use patterns, in large part because of the effects of winter and seasonality on forage production, availability and quality. Snow and weather influence mountain ungulates by increasing costs of thermoregulation, energetic costs of locomotion and by the burial of preferred forage (Burles and Hoefs 1984; Parker et al. 1984; Daily and Hobbs 1989). Ungulates that typically live at high elevations cope with winter and deep snow cover by using a variety of strategies. Some ungulates alter vegetation use (alpine chamois ( Rupicapra rupicapra (L., 1758)) and Himalayan tahr ( Hemitragus jemlahicus (Smith, 1826)): Forsyth 2000), including movement to areas of heavier cover (mountain caribou ( Rangifer tarandus (Gmelin, 1788)): Apps et al. 2001) or movement to open, high-elevation habitats in shallow snow zones (bighorn sheep (Ovis canadensis (Shaw, 1804)): Demarchi et al. Draft2000; mountain goats ( Oreamnos americanus (Blainville, 1816)): Poole et al. 2009; Abruzzo chamois ( R. pyrenaica ornate (Bonaparte, 1845)): Lovari and Cosentino 1986). When snow depths increase, some may move to lower elevations (chamois: Lovari and Cosentino 1986) or to higher elevations later in the winter to areas of deeper snow for access to arboreal forage (mountain caribou: Apps et al. 2001). Lastly, some species move to escape terrain and moderate slopes during winter (Asiatic ibex ( Capra ibex sibrica (Pallas, 1776)) and blue sheep ( Pseudois nayaur (Hodgson, 1833)): Namgail 2006). Habitat selection by ungulates is thought to be a trade-off between nutritional and anti- predation constraints (Festa-Bianchet 1988 a; Hebblewhite and Merrill 2011). In western North America, seasonal habitat selection by bighorn sheep varies among populations likely in response to both predation risk and snow depth (Shackleton et al. 1999; Demarchi et al. 2000; Krausman and Bowyer 2003). Proximity to escape terrain is an important aspect of most sheep habitat selection (e.g., Tilton and Willard 1982; DeCesare and Pletscher 2006; Bleich et al. 2009). https://mc06.manuscriptcentral.com/cjz-pubs Canadian Journal of Zoology Page 4 of 46 4 The east side of the Elk Valley in southeastern British Columbia (BC) is home to a population of Rocky Mountain bighorn sheep ( O. c. canadensis ) of provincial significance; the Ewin Ridge sheep range has been considered the most important bighorn sheep winter range in BC (Demarchi 1968). Sheep typically winter at lower elevations to avoid deep snows that accumulate in most parts of their range (e.g., Tilton and Willard 1982), however, sheep in the Elk Valley are unique as they generally winter at high elevation on windswept, south-facing native grasslands. Lower elevation habitat in this area is primarily forested with heavy snow accumulation. The Elk Valley supports important industrial activities, primarily coal mining and forestry. Four large, open-pit coal mines occur within the east side of the Elk Valley (Fig. 1), and sheep use areas of some mine sites to varying extent year-round (K. Podrasky, Teck Coal, unpubl. data). Coal mines can create bighorn sheep habitat where none Draftexisted previously, as has occurred at mines in the Alberta foothills (MacCallum 1991; MacCallum and Geist 1992). At these Alberta mines, bighorn sheep from the adjacent occupied alpine habitat responded to the mine reclamation by occupying the new habitats, expanding their range, and exhibiting rapid population growth. Bighorn sheep also can use urban environments, which can provide higher forage quality (Rubin et al. 2002; Dibb et al. 2008). While human disturbance (e.g., noise, activity) from mines do not appear to deter use by sheep per se (Oehler et al. 2005; Jansen et al. 2006, 2009; Bleich et al. 2009), expansion of coal mining may cause direct loss of winter range. Winter range is important habitat for bighorn sheep (Demarchi et al. 2000), and has been suggested as the single most important factor limiting sheep populations in the Elk Valley area (Schuerholz 1984). The late winter/early spring (green-up) period is particularly important, as delayed green-up may cause starvation in sheep populations (Burles and Hoefs 1984). Identifying high value habitats can help assess and manage the potential impacts of industrial activities. There is concern about management of mountain sheep and the potential impacts that habitat alteration might have on those ungulates (Bleich et al. 2009). Incomplete knowledge about bighorn https://mc06.manuscriptcentral.com/cjz-pubs Page 5 of 46 Canadian Journal of Zoology 5 sheep ecology, including important winter use areas and habitat selection, can be an obstacle to coordinating sheep management activities. We hypothesized that ( i) winter habitat selection would differ between sheep wintering on native grasslands and those using active coal mine areas because of limitations to how mine areas can duplicate establishment of native ranges, and ( ii ) greater winter severity would result in smaller seasonal range size and decreased sheep survival. The information collected in this study could be applied to other regions where mountain ungulate range and resource development overlap. Materials and methods Study area The 830 km 2 study area is located in the Rocky Mountains of southeastern BC, and focused on bighorn sheep populations wintering east Draftof the Elk River and stretching up to the Continental Divide (Fig. 1). Biogeoclimatic zones within the study area grade from Montane Spruce dry cool (MSdk) in valley bottoms, Engelmann Spruce–Subalpine Fir dry cool (ESSFdk, including subalpine parkland) at higher elevations, to small amounts of Alpine Tundra (AT) on ridge and mountain tops (Braumandl and Curran 1992). Krummholz subalpine fir ( Abies lasiocarpa (Hook.) Nutt.) with scattered whitebark pine (Pinus albicaulis (Engelm.) Rydb.) dominate the treeline, whereas closed to open stands of Engelmann spruce (Picea engelmannii Parry), subalpine fir, lodgepole pine ( Pinus contorta Dougl. ex Loud.), and aspen ( Populus tremuloides Michx) are found at lower elevations. Cliffs of various sizes, and open scree slopes and meadows are located