Status of the Red-tailed Chipmunk (Tamias ruficaudus) in ... · Chipmunk (Tamias amoenus) and Red-tailed Chipmunk (Tamias ruficaudus), larger chipmunks that exclude the Least Chipmunk

STATUS OF THE LEAST CHIPMUNK (TAMIAS MINIMUS) SUBSPECIES T. M. OREOCETES AND T. M. SELKIRKI

IN BRITISH COLUMBIA

by D. Nagorsen

Illustration © Michael Hames

Victoria, B.C.

Wildlife Working Report No. WR 116 December 2004

i

Wildlife Working Reports frequently contain preliminary data, so conclusions based on these may be subject to change. Working Reports receive little review. They may be cited in publications, but their manuscript status should be noted. Copies may be obtained on-line from http://www.env.gov.bc.ca/wld/ or from the Ministry of Environment, Ecosystems Branch, P.O. Box 9338 Stn. Prov. Govt., Victoria, BC V8W 9M1. © Province of British Columbia ISBN 978-0-7726-6289-7 Date: May 6, 2010 British Columbia. Ministry of Environment. Status of the Least Chipmunk (Tamias minimus) subspecies T. m. oreocetes and T. m. selkirki in British Columbia Citation Nagorsen, D.W. 2004. Status of the Least Chipmunk (Tamias minimus) subspecies T. m. oreocetes and T. m. selkirki in British Columbia. B.C. Ministry of Environment, Victoria, BC. Wildlife Working Report No. WR 116. 37pp.

ii

http://www.env.gov.bc.ca/wld/

DISCLAIMER

In cases where a Wildlife Working Report or Bulletin is also a species’ status report, it may contain a status recommendation from the author. The Province, in consultation with experts, will determine the official conservation status and consider official legal designation. The data contained in the status report will be considered during those processes. NOTE: The content of this report was completed in March of 2004 and reflects the state of our knowledge of this species at that time. It has not been updated prior to publication April 2010. Information on current status of native species in British Columbia can be found through B.C. Species and Ecosystems Explorer http://www.env.gov.bc.ca/atrisk/toolintro.html

iii

http://www.env.gov.bc.ca/atrisk/toolintro.html

ACKNOWLEDGMENTS

This status report was funded by the British Columbia Ministry of Water, Air and Land Protection. Mark Fraker, who initiated the Kootenay chipmunk research project in 1996, collected some of the specimens and habitat data that provide a basis for this report. Nick Panter assisted with field work in the Kootenay chipmunk research project, and prepared the voucher specimens and genital bone preparations used for identification. Ian Parfitt created the range map and provided a digital file of the map; Dana Diotte created the map of coalfields. Dave Grieve provided information on coalfields in the Kootenay region of British Columbia. I thank Laura Friis, John Krebs, and Ted Antifeau for their support. The following museums provided the author with their museum records and specimen loans of Least Chipmunk s from British Columbia: American Museum of Natural History, New York; Canadian Museum of Nature, Ottawa; Museum of Vertebrate Zoology, University of California, Berkeley; Royal British Columbia Museum, Victoria; Cowan Vertebrate Museum, University of British Columbia, Vancouver.

iv

SUMMARY The Least Chipmunk (Tamias minimus), found throughout the boreal forest and western Cordillera, has the largest distributional area of any chipmunk. Twenty-one subspecies are recognized; four occur in British Columbia. Two subspecies, T. m. oreocetes and T. m. selkirki, are confined to alpine areas in the southern Rocky and Purcell Mountains and are of conservation concern. They are the only subspecies of the Least Chipmunk that are confined to alpine. Although inadequate samples prohibit definitive conclusions about their taxonomic status, their divergence in male genital morphology, disjunct distributions, and restriction to alpine suggest they qualify as distinct units for management, conservation, and ranking. T. m. selkirki has probably been isolated in the Purcell Mountains since the early postglacial, and it may represent a phylogeographic lineage separate from Least Chipmunks in the Rocky Mountains. T. m. oreocetes inhabits a small area in the Rocky Mountains of Glacier National Park, Montana and the southern Rocky Mountains of British Columbia and Alberta where its range extends as far north as the Bow River and Kicking Horse Pass. In British Columbia, it inhabits the subalpine-alpine from about 1945 to 2320 m. Krummholz tree islands and talus are the preferred habitat. Its narrow elevational range is largely the result of competition with the Yellow-pine Chipmunk (Tamias amoenus) and Red-tailed Chipmunk (Tamias ruficaudus), larger chipmunks that exclude the Least Chipmunk from forest. T. m. selkirki is known from only two localized areas in the southern Purcell Mountains of British Columbia: Springs Creek basin and Mount Brewer. T. minimus appears to be absent from the northern Purcell Mountains and the Selkirk Mountains. T. m. selkirki is known from a narrow elevational zone of about 2134 to 2380 m where it inhabits tree islands and talus similar to T. m. oreocetes. T. minimus is a facultative hibernator. Rather than accumulating heavy fat reserves, it depends on seeds stored in its burrow for winter survival. T. m. oreocetes and T. m. selkirki demonstrate several adaptations for survival in a harsh alpine environment—a small body size, lower metabolic rates, reduced fecundity, and wary behaviour. Breeding begins shortly after animals emerge from hibernation in spring. Females produce only one litter in the breeding season; only 25–50% of yearling females will breed. There are few threats to these subspecies. They are not affected by forest harvesting or forest fire, and are tolerant of human activity associated with ski developments or wilderness camping. Open pit coal mines in the Rocky Mountains have altered some alpine talus habitats, but these mines represent an insignificant portion of the range of T. m. oreocetes. Off-road vehicles are active in the Springs Creek basin, but T. m. selkirki is associated with talus areas above the old roads and open meadows. The British Columbia Conservation Data Centre currently ranks T. m. oreocetes as S2S3 because of its limited range and few occurrences. Although it has a restricted range in British Columbia (extent of occurrence is 150 km2 and includes 10 known occurrences), much of its Canadian range occurs within provincial and national protected areas along the Continental Divide. Except for the localized

v

effects of open pit coal mines, no threats are known. There is no evidence of habitat or population declines. Populations of T. m. oreocetes in British Columbia are connected to populations in Montana and Alberta. About 40% of the distributional area of this subspecies is in British Columbia, and 90% is in Canada. A Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessment of this subspecies will have to include data from the Alberta population. T. m. selkirki is ranked as S1S3 by the British Columbia Conservation Data Centre; it is ranked as Vulnerable in the International Union for Conservation of Nature and Natural Resources (IUCN) Red Book. It is endemic to British Columbia, and its distributional range is restricted to two localized areas in the southern Purcell Mountains (extent of occurrence is about 30 km2 and includes about five occurrences). The area of occupancy is probably less than 100 km2, and the number of mature animals is less than 1000. No threats are known other than stochastic extinction events associated with small, isolated populations and possible future mining activity. Priorities for conserving and managing T. m. oreocetes include molecular studies to verify the taxonomic validity of this race, and inventories in the mountains west of the Flathead River valley to determine the limits of its range. More inventory is essential to determine if T. m. selkirki is present in the Purcell Wilderness Conservancy and to what extent the Springs Creek and Mount Brewer occurrences are isolated subpopulations. Future mining activity and off- road vehicle activity at the Paradise Mine site near the Springs Creek basin should be monitored for their possible impact on T. m. selkirki.

vi

TABLE OF CONTENTS

SUMMARY .................................................................................................................................... ii ACKNOWLEDGMENTS .............................................................................................................. iv TABLE OF CONTENTS .............................................................................................................. vii LIST OF APPENDICES .............................................................................................................. viii LIST OF FIGURES ...................................................................................................................... viii 1 SPECIES INFORMATION ..................................................................................................... 1

1.1 Name and Classification ................................................................................................... 1 1.2 Description ........................................................................................................................ 2 1.3 Nationally Significant Populations ................................................................................... 3

2 BIOLOGY ................................................................................................................................ 3 2.1 General .............................................................................................................................. 3 2.2 Reproduction ..................................................................................................................... 3 2.3 Physiology ........................................................................................................................ 4 2.4 Movements/Dispersal ....................................................................................................... 4 2.5 Nutrition and Interspecific Interactions ............................................................................ 4 2.6 Behaviour and Adaptability .............................................................................................. 5

3 HABITAT ................................................................................................................................ 5 3.1 Habitat Requirements ........................................................................................................ 5 3.2 Trends in Habitat Quality and Quantity ............................................................................ 6 3.3 Protection/Ownership ....................................................................................................... 9

4 DISTRIBUTION ...................................................................................................................... 9 4.1 Global/ North American ................................................................................................... 9 4.2 British Columbia ............................................................................................................... 9

5 POPULATION SIZE AND TRENDS ................................................................................... 13 6 LIMITING FACTORS AND THREATS .............................................................................. 13 7 SPECIAL SIGNIFICANCE OF THE SPECIES.................................................................... 15 8 EXISTING PROTECTION OR OTHER STATUS ............................................................... 15 9 RECOMMENDATIONS AND MANAGEMENT OPTIONS .............................................. 16

9.1 Inventory ......................................................................................................................... 16 9.2 Habitat Protection and Acquisition ................................................................................. 16

10 EVALUATION .................................................................................................................. 17 10.1 Provincial Ranking.......................................................................................................... 17

10.1.1 T. m. oreocetes (see Appendix 2) ................................................................................ 17 10.1.2 T. m. selkirki (see Appendix 3) ................................................................................... 18

10.2 COSEWIC Ranking ........................................................................................................ 19 11 AUTHORITIES CONSULTED ......................................................................................... 20 12 LITERATURE CITED ....................................................................................................... 20

vii

viii

LIST OF FIGURES

Figure 1. Springs Creek basin, Purcell Mountains. The site of the Paradise Mine and the type locality of T. m. selkirki ............................................................................................................ 7

Figure 2. Talus and subalpine larch habitat used by T. m. selkirki in the Springs Creek basin .................................................................................................................. 7

Figure 3. Old burn below the alpine zone occupied by T. m. oreocetes, Middle Kootenay Pass, Rocky Mountains. The Red-tailed Chipmunk (Tamias ruficaudus) was also taken near this site .................................................................... 8

Figure 4. Talus and boulders occupied by T. m. oreocetes, basin above Tod Hunter Creek, Rocky Mountains ...................................................................................... 8

Figure 5. Mineral tenures in the Springs Creek basin and Paradise Mine area, Purcell Mountains . ................................................................................................................ 10

Figure 6. North American distribution of the Least Chipmunk (Tamias minimus). ...................... 11 Figure 7. Distribution of the Least Chipmunk subspecies T. m. oreocetes and

T. m. selkirki in British Columbia. ......................................................................................... 12 Figure 8. Distribution of T. m. oreocetes and coal fields in the southern

Rocky Mountains of British Columbia. .................................................................................. 14

LIST OF APPENDICES Appendix 1. Known occurrences of T. m. oreocetes and T. m. selkirki in British Columbia based

on museum specimens and literature records. ........................................................................ 23 Appendix 2. TECHNICAL SUMMARY - Tamias minimus oreocetes ........................................ 26 Appendix 3. TECHNICAL SUMMARY - Tamias minimus selkirki ............................................ 28

1 SPECIES INFORMATION

1.1 Name and Classification The Least Chipmunk (Tamias minimus [Bachman 1830]) is a member of the rodent family Sciuridae. In the early literature, this species was classified as Eutamias minimus; however, in the recent literature, all North American chipmunk species are classified in the genus Tamias (Wilson and Reeder 1993). Nevertheless, generic classification of the chipmunks is unresolved. Recent data from ectoparasites (Jameson 1999) and mitochondrial DNA (mtDNA) (Piaggio and Spicer 2001) suggest that western North American chipmunks are sufficiently distinct to be separated into the genus Neotamias. Based on molecular data, Piaggio and Spicer (2001) concluded that T. minimus was a member of the minimus species group, which also includes the Panamint Chipmunk (Tamias panamintinus), Red-tailed Chipmunk (Tamias ruficaudus), and Long-eared Chipmunk (Tamias quadrimaculatus).

Twenty-one subspecies of T. minimus are recognized (Hall 1981; Verts and Carraway 2001). Six are found in Canada; four occur in British Columbia: T. m. borealis, T. m. caniceps, T. m. oreocetes, and T. m. selkirki (Cowan and Guiguet 1965). T. m. borealis and T. m. caniceps are not of conservation concern because of their large distributional ranges in northern Canada. T. m. selkirki is a highly isolated subspecies that is restricted to high elevations in the Purcell Mountains. T. m. oreocetes is confined to a small area in the extreme southern Rocky Mountains of Canada and Glacier National Park, Montana.

Cowan (1946) described and named T. m. selkirki on the basis of its pelage colour and tail size. Nagorsen et al. (2002) questioned the divergence in tail size and pelage colour in this form, but they demonstrated that it is differentiated from populations in the adjacent Rocky Mountains in male genital bone (bacula) and skull morphology, lending support to Cowan's (1946) classification of this population as a distinct subspecies. The divergence in bacular morphology is significant because this trait is an important taxonomic character in chipmunks (Sullivan 1985; Sullivan and Petersen 1988). T. m. selkirki is allopatric, separated by 100 km from T. minimus in the Rocky Mountains. Nagorsen et al. (2002) hypothesized that T. m. selkirki is a relict population that was isolated in alpine habitats of the Purcell Mountains during the early postglacial. T. m. oreocetes was described and named by Merriam (1897) as a distinct species (Eutamias oreocetes) on the basis of the type specimen taken from the Rocky Mountains of Montana. Howell (1922, 1929) reduced this taxon to a subspecies of T. minimus (T. m. oreocetes); he speculated that it ranged from northern Montana to southwestern Alberta. Most researchers (Crowe 1943; Banfield 1958; Meredith 1975, 1977) consider the range of T. m. oreocetes to extend along the Continental Divide from northern Montana as far north as Banff and Yoho National Parks where it is separated from T. m. borealis to the north by the Bow River and Kicking Horse Pass and intervening low-elevation populations of the Yellow-pine Chipmunk (Tamias amoenus). According to Howell (1929), T. m. oreocetes differs from T. m. borealis, the adjacent subspecies in Canada, by having paler dorsal stripes, paler hind feet, a shorter tail, and a shorter skull. Subsequent taxonomic accounts (Crowe 1943; Banfield 1958; Soper 1964)

1

essentially repeat Howell's (1929) diagnostic traits. However, Cowan (1946) suggested that pelage traits were most reliable for distinguishing T. m. oreocetes and T. m. borealis, particularly in their contact zone. The limited samples of T. m. oreocetes and T. m. borealis analyzed by Nagorsen et al. (2002) showed no evidence of a morphometric discontinuity in skull morphology among the Rocky Mountain populations, but they differed in male genital bone morphology. Nagorsen et al. (2002) concluded that until more bacular samples are obtained and molecular studies are done, it is prudent to continue to recognize populations south of the Bow River and Kicking Horse Pass in the Canadian Rocky Mountains as a separate subspecies: T. m. oreocetes. Molecular studies with allozymes and DNA are essential to resolve the systematics of T. m. selkirki and T. m. oreocetes. Tissue samples for DNA analysis were collected by Nagorsen et al. (2002) from their specimens of T. m. selkirki and T. m. oreocetes. Samples were deposited with John Demboski at the Biological Sciences Department, California State Polytechnic University and are to be analyzed by a graduate student. The high divergence in mtDNA sequences among several subspecies of T. minimus reported by Piaggio and Spicer (2000) suggests that this species consists of several distinct phylogeographic lineages. Another common name for this species is Western Chipmunk. A common name for T. m. oreocetes is the Timberline Chipmunk (Anderson 1946). No common name exists for T. m. selkirki. The use of the subspecies name selkirki by Cowan (1946) was inappropriate because this race is known only from the Purcell Mountains.

1.2 Description The Least Chipmunk, the smallest chipmunk in Canada, has the typical striping pattern of five dark and four light stripes. Generally, the dorsal pelage is greyish-brown with a grey rump, a white or grey belly, and pale yellow to light orange on the neck, sides, dorsal surface of the hind feet, and the underside of the tail. The dental formula is 1/1 incisors, 0/0 canines, 2/1 premolars, and 3/3 molars. In the Purcell and southern Rocky Mountains of southeastern British Columbia, T. minimus co-occurs in the alpine-subalpine ecotone with T. amoenus. T. minimus is smaller (total length less than 195 mm, skull length less than 32.5 mm, mandible length less than 17.5 mm), and it has a white or grey belly in contrast to the buffy belly of T. amoenus. Genital bones of T. minimus are diagnostic. Its baculum is small (shaft length less than 3.2 mm with a tip that is less than 30% of the shaft length), and the female genital bone (i.e., baubellum) is small (greatest length 0.9–1.1 mm) with a distinct "U"-shaped base that tapers sharply at its proximal end (Nagorsen 2002; Nagorsen et al. 2002). T. m. selkirki and T. m. oreocetes tend to be paler than the northern subspecies T. m. borealis. Soper (1964) described the distinct pale grey pelage of T. m. oreocetes as a diagnostic trait, and naturalists have described this form as “ghostly”. Some of this pale colour can be attributed to old, faded, winter pelage. Because it is restricted to high alpine areas in the Rocky Mountains, the spring moult is delayed in this subspecies, with some animals not acquiring their bright summer pelage until early autumn. Cowan (1946) described T. m. selkirki as resembling T. m. oreocetes in pelage colour but with a brighter fur colour and whitish upper surfaces of its feet.

2

T. m. selkirki and T. m. oreocetes are also smaller than T. m. borealis. Sheppard (1965) noted that subspecies of the Least Chipmunk that are associated with desert or alpine habitats tend to have smaller body sizes than subspecies that are associated with forests. Mean representative body measurements (range in parentheses) for adult specimens of T. m. selkirki are as follows: total length = 186 mm (172–193), tail vertebrae = 81 mm (69–91), hind foot = 31 mm (27–34), ear = 14 mm (12–16), and body mass = 41.4 g (38.1–52.8). Mean representative body measurements (range in parentheses) for adult specimens of T. m. oreocetes are as follows: total length = 192 mm (165–210), tail vertebrae = 80 mm (59–88), hind foot = 31 mm (29–33), ear = 14 mm (14–18), and body mass = 43.9 g (36.5–59.0) (see Nagorsen et al. 2002).

1.3 Nationally Significant Populations Inadequate samples prohibit definitive conclusions about the taxonomy of T. minimus in the southern Columbia and Rocky Mountains of Canada. Nevertheless, because of their putative taxonomic differences, isolated distributions, and restriction to alpine environments, T. m. selkirki and T. m. oreocetes warrant treatment as distinct evolutionary units for conservation and management.

2. BIOLOGY The biology of the Least Chipmunk has been well studied. Because much of this research has been done on subspecies associated with arid grassland or boreal forest communities (Verts and Carraway 2001), some of this literature may not be relevant to the alpine subspecies T. m. oreocetes and T. m. selkirki. No life history data exist for T. m. selkirki. In contrast, Sheppard (1965) and Meredith (1975) described the life history and behaviour of T. m. oreocetes from the Rocky Mountains of Alberta as part of their research for their Ph.D. dissertations. Most of this section is based on their findings.

2.1 General T. m. selkirki and T. m. oreocetes are adapted to environments with severe climate, a short growing season, limited food resources, and reduced vegetation cover. Their adaptations include a small body size, reduced fecundity, and shy, wary behaviour.

2.2 Reproduction The gestation period in the Least Chipmunk is 28–30 days (Verts and Carraway 2001). Reproductive data for T. m. selkirki are limited to data associated with museum specimens. A nursing female was captured 18 August; the earliest young- of-the-year specimen was captured 31 July. In the southern Rocky Mountains of Alberta, male T. m. oreocetes emerge before females in April; the first females appear above ground in mid April (Sheppard 1969). Mating occurs in late April through May and the young are born in June. The latest birth recorded by Sheppard (1969) was 24 June. The young first appear above ground in mid July after nursing in their underground burrow for about 35–40 days. Females produce only one litter each year; mean litter size (± standard error) based on embryo counts was 4.19 ± 0.22 (Sheppard 1969). Newborn Least Chipmunks are naked, blind, and weigh about 2 g. Least Chipmunks can breed in the spring after their birth, but in southwestern Alberta, as many as one third of the yearling chipmunks may fail to breed. The age at sexual maturity varies considerably from year to year. During the four years of Sheppard's (1969)

3

study, he estimated that the proportion of yearlings that bred ranged from 26 to 52% for females, and 28 to 86% in males.

2.3 Physiology The Least Chipmunk is a facultative hibernator, relying on hoarded seeds for winter survival rather than accumulating fat reserves. Winter stores analyzed by Criddle (1943) weighed 464–800 g and were comprised of seeds and grain. From experiments on captive Least Chipmunks, Pivorun (1976) found that torpor bouts lasted about 88–110 hours during the hibernation period. When exposed to temperatures from 16 to 3°�C, this species maintained its body temperature about 1°C above the ambient temperature during torpor. Other than Sheppard's (1969) observation of females emerging from hibernation during April, no data are available on emergence dates or the length of the hibernation period for T. m. oreocetes and T. m. selkirki. The Least Chipmunk is adapted to a greater range of environments than any other North American chipmunk. Subspecies and even local populations of a subspecies may be adapted physiologically to local environments (Willems and Armitage 1975a, 1975b, 1975c). Jones and Wang (1976) demonstrated that T. m. oreocetes had a lower estimated basal metabolic rate than T. amoenus (taken from the same area) and samples of T. m. borealis from the Rocky Mountains of Alberta. They speculated that a lower metabolic rate is an adaptation for reducing energy demands in a harsh alpine environment. Sheppard (1965) found that captive T. m. oreocetes consumed less food than the Yellow-pine Chipmunk.

2.4 Movements/Dispersal No estimates of home range size exist for T. m. selkirki. Sheppard (1972) estimated home range size for T. m. oreocetes at 1.22 ha (0.39–3.45) for males and 0.66 ha (0.22–1.51) for females. The large home range size of this small chipmunk probably reflects the low plant density and productivity in the alpine. Meredith (1974) recorded distances between trap captures of this subspecies at 100–530 m. The longest movement (530 m) was made by a nursing female.

2.5 Nutrition and Interspecific Interactions The Least Chipmunk’s diet includes seeds, arthropods, leaves, fruits, flowers, and fungi (Verts and Carraway 2001). Based on material collected from cheek pouches of T. m. oreocetes, Sheppard (1965) determined that sedges (Carex sp.), gooseberry (Ribes sp.), soopolallie (Shepherdia canadensis), rose (Rosa sp.), field chickweed (Cerastium arvense), kinnikinnick (Arctostaphylos uva-ursi), cinquefoil (Potentilla sp.), and timothy (Phleum sp.) were important foods. Other seeds found in T. m. oreocetes cheek pouches included Vaccinium sp., common juniper (Juniperus communis), lodgepole pine (Pinus contorta), strawberry (Fragaria sp.), oatgrass (Danthonia sp.), early blue violet (Viola adunca), knotweed (Polygonum sp.), small-flowered blue-eyed Mary (Collinsia parviflora), and common harebell (Campanula rotundifolia). In captivity, T. m. oreocetes consumed about 3.95 g of food per day. The mostly likely competitor for food resources is T. amoenus. In the southern Rocky Mountains, Sheppard (1965, 1971) found that T. minimus and T. amoenus have similar diets. Minor differences in plant species exploited and seed sizes appear to reflect availability rather than different feeding niches. Because of the elevational segregation of these species in the Rocky and Purcell Mountains,

4

competition for food resources is restricted to a narrow zone in the alpine-subalpine ecotone. Other small mammals that co-occur with T. m. oreocetes and T. m. selkirki in alpine talus habitats are the American Pika (Ochtotona princeps) and Golden-mantled Ground Squirrel (Spermophilus lateralis), small mammals that show some dietary overlap with the Least Chipmunk. The degree of interspecific competition among these mammals is not clear, but Smith (1995) demonstrated that T. minimus and S. lateralis may exploit different microhabitats while foraging.

2.6 Behaviour and Adaptability The social biology of the Least Chipmunk has not been studied. According to Chappell (1978), this species does not defend large exclusive territories; home ranges evidently overlap among individuals of each sex and age category. Although less arboreal than the arboreal Red-tailed Chipmunk, the Least Chipmunk is capable of climbing, and occasionally will den in trees (Broadbrooks 1974; Verts and Carraway 2001). Crowe (1943) observed a T. m. oreocetes climb a 4.9-m spruce tree. Nevertheless, with their propensity for the alpine, T. m. oreocetes and T. m. selkirki presumably den in underground burrows. Bihr and Smith (1998) observed that subalpine populations of Least Chipmunk in Colorado mostly burrowed under large rocks. The underground burrows are typically shallow, situated 14–50 cm below the surface. They may be simple structures consisting of a single passageway (0.2–1.5 m in length) with several openings or complex structures reaching 3.5 m in length with multiple passages and openings. Each burrow system has a single nest constructed from hair, bird feathers, dried shredded grass, bark, and downy fibres from willow or poplar catkins (Criddle1943; Bihr and Smith 1998). From laboratory experiments, Meredith (1976) concluded that T. m. oreocetes preference for talus is partly innate. Sheppard (1965, 1971) noted that T. m. oreocetes was more alert and difficult to approach in the field than T. amoenus. In captivity, T. m. oreocetes appeared to be more hesitant at exploring its nest box. Nagorsen and Fraker (pers. obs.) observed similar behaviour by T. m. selkirki in the field. They rarely observed this chipmunk far from the protective cover of talus or shrubby trees. This wary behaviour is presumably a strategy for avoiding predators in open alpine environments. T. minimus emits “ventriloquist”-like vocalizations that are difficult to locate. The Least Chipmunk is little disturbed by human activity and often habituates to campgrounds and areas with human dwellings.

3 HABITAT

3.1 Habitat Requirements Although the Least Chipmunk inhabits a wide spectrum of habitats across North America, including forest and desert (Verts and Carraway 2001), the subspecies T. m. oreocetes and T. m. selkirki are limited to alpine areas at or above treeline. In the Purcell Mountains of southern British Columbia, T. m. selkirki is known from a narrow elevational zone of 2134–2380 m (Appendix 1). Known occurrences are in the Alpine Tundra and Englemann Spruce–Subalpine Fir (AT/ESSFdkp) biogeoclimatic zones (Nagorsen et al. 2002). In the

5

Springs Creek basin (Figures 1, 2), it inhabited complex rocky talus formations with scattered subalpine larch (Larix lyalii). Carl and Hardy (1945) also observed it around buildings at the Paradise Mine in 1944. In the Mount Brewer area, Nagorsen et al. (2002) found T. m. selkirki in scattered tree islands of subalpine larch, whitebark pine (Pinus albicaulis), subalpine fir (Abies lasiocarpa), and common juniper, and in talus on open ridges above treeline.

In the Rocky Mountains of British Columbia, T. m. oreocetes is confined to the alpine-subalpine from about 1945 to 2318 m (Appendix 1). The known occurrences of T. m. oreocetes in British Columbia are all in the Alpine Tundra and Englemann Spruce–Subalpine Fir (AT/ESSFdkp, ESSFdk) biogeoclimatic zones (Nagorsen et al. 2002). Most of the historical museum specimen records are from talus or tree island habitats. In Middle Kootenay Pass, this chipmunk inhabited talus and woody debris associated with an old burn (Figure 3); at Tod Hunter Creek it was restricted to talus and large boulders in an open basin above treeline (Figure 4). T. m. oreocetes occupies similar habitats in Alberta (Sheppard 1965, 1971; Soper 1973; Meredith 1975, 1976; Wallis and Wershler 1997) where it has been found in talus slides, alpine fell fields, and open forest in subalpine tree islands. Sheppard (1971) observed T. m. oreocetes living at elevations as low as 1800 m in rock slides on some mountains in Alberta.

The narrow elevational zone inhabited by T. m. oreocetes in the Rocky Mountains of Canada has been attributed to competitive exclusion with T. amoenus and T. ruficaudus. In Sheppard's (1965) and Meredith's (1975) Alberta study areas in the Goat Valley and the University of Alberta Biological Station, T. m. oreocetes co-occurred with T. amoenus. The two species are parapatric with a contact zone in open forest patches that border the alpine. Results from arena experiments on captive animals and from field observations (Sheppard 1971; Meredith 1977) demonstrated that the larger, more aggressive T. amoenus is dominant and excludes T. m. oreocetes from forested habitats. Transplant experiments demonstrated that T. m. oreocetes can survive in forest. In the northern Rocky Mountains, where it is the only chipmunk, T. minimus inhabits forests. Although alpine habitat is within the fundamental niche of T. amoenus, the species is excluded from alpine habitats in the southern Rocky Mountains by T. m. oreocetes, which has several physiological advantages in severe alpine environments. In the Rocky Mountains south of Crowsnest Pass where three chipmunk species co-occur, both T. ruficaudus and T. amoenus presumably exclude T. m. oreocetes from forest (Hoffmann 1974).

A similar pattern occurs in the Purcell Mountains where T. amoenus inhabits forest and subalpine but is absent from alpine areas occupied by T. m. selkirki (Nagorsen et al. 2002). In northern areas of the Purcell Mountains and Mount Revelstoke National Park in the Selkirk Mountains where T. minimus is absent, the distribution of T. amoenus extends into the alpine (Cowan and Munro 1945; van Tighem and Gyug 1984; Nagorsen, unpublished data)

3.2 Trends in Habitat Quality and Quantity There is no evidence of declines in the quality or quantity of habitat in British Columbia. Forest harvesting has not impacted the habitat of these subspecies because both live at or above treeline. Roads, ski developments, and wilderness hiking trails have not affected the habitat. Some alpine habitat in the Rocky Mountains of southern British Columbia has been lost due to open pit coal mining, but this represents an insignificant portion of the British Columbia range of T. m. oreocetes.

6

Figure 1. Springs Creek basin, Purcell Mountains. The site of the Paradise Mine and the type locality of T. m. selkirki. (Photograph by D.W. Nagorsen)

Figure 2. Talus and subalpine larch habitat used by T. m. selkirki in the Springs Creek basin. (Photograph by D.W. Nagorsen)

7

Figure 3. Old burn below the alpine zone occupied by T. m. oreocetes, Middle Kootenay Pass, Rocky Mountains. The Red-tailed Chipmunk (Tamias ruficaudus) was also taken near this site. (Photograph by D.W. Nagorsen)

Figure 4. Talus and boulders occupied by T. m. oreocetes, basin above Tod Hunter Creek, Rocky Mountains. (Photograph by D.W. Nagorsen)

8

3.3 Protection/Ownership There are no quantitative data on land tenure classification for the range of the Least Chipmunk in British Columbia. Much of the range of T. m. oreocetes is in protected areas (national and provincial parks), but the percentage of range in protected areas has not been quantified. Other portions of its range are mostly on Crown land, although some of this is in areas with mining leases associated with coalfields. The proportion of this subspecies’ range that falls within coalfields and coal leases has not been quantified. The two known populations (Mount Brewer, Paradise Mine) of T. m. selkirki are on Crown land. All of the known occurrences in the Springs Creek basin–Paradise Mine area are in areas with mining claims (Figure 5). There are no mining claims in the Mount Brewer area.

4 DISTRIBUTION

4.1 Global/ North American The Least Chipmunk has the largest range of any chipmunk in North America, inhabiting Alaska, Canada from the Yukon Territory to western Quebec, and the north-central and western United States (Figure 6). Isolated populations occur in New Mexico and Arizona at the southern edge of the species' range.

4.2 British Columbia In northern British Columbia, the Least Chipmunk is continuously distributed as far south as the Omineca and Babine Mountains, and the Rocky Mountains south of the Peace River (Cowan and Guiguet 1965; Nagorsen, unpublished data). South of 55° latitude, it is restricted to areas above treeline in the Rocky Mountains and southern Purcell Mountains. T. m. selkirki is known from only two localized areas above treeline in the southern Purcell Mountains (Appendix 1; Figure 7): Springs Creek basin and Mount Brewer. Springs Creek basin, north of Toby Creek, is the location of the historic Paradise Mine site and the type locality for this subspecies (Carl and Hardy 1945; Cowan 1946). Mount Brewer is part of a continuous alpine ridge system that extends into the Purcell Wilderness Conservancy. Alpine areas in the Springs Creek basin and Mount Brewer are separated by the Toby Creek valley. T. m. selkirki inhabiting these two areas could be regarded as subpopulations because they are separated by lowland forest and intervening populations of T. amoenus. The two subpopulations could be connected in the Jumbo Pass area, but no chipmunk inventories have been done in this region. Northern limits of the range of T. m. selkirki in the Purcell Mountains are also not clear. Nagorsen et al. (2002) did not find this species in alpine areas at Lead Queen Mountain near the Bugaboos, and it is evidently absent from Glacier National Park (van Tighem and Gyug 1984; Nagorsen, pers. obs). T. minimus also appears to be absent from the Selkirk Mountains. Cowan and Munro (1945) and van Tighem and Gyug (1984) reported that T. amoenus was the only chipmunk species present in Revelstoke National Park. No historical museum specimens of T. minimus exist for the Selkirk Mountains; nevertheless, no chipmunk collections have been made from alpine areas of the Goat Range, the Valhalla Mountains, or the Kokanee Glacier area. Although Panian (1996) reported a

9

male T. minimus from Gibson Lake in the Kokanee Glacier area, the identification is suspect. No voucher specimen was kept by Panian (1996) to substantiate his identification. Unfortunately, the x-ray image of the genital bone in his report is too fuzzy to identify to species, and no diagnostic genital bone measurements were taken (see Nagorsen et al. 2002). The elevation of his capture (1590 m) is well below the elevational range of T. m. selkirki and is within the elevational range of T. amoenus.

Figure 5. Mineral tenures in the Springs Creek basin and Paradise Mine area, Purcell Mountains. Purple polygons denote mining leases; red polygons (CG) denote Crown grant 2 post claims. Arrows indicate documented locations of T. m. selkirki. Modified from Mineral Title Reference Map M082K040, British Columbia Ministry of Sustainable Resource Management.

10

T. m. selkirki is allopatric with other populations of T. minimus in western Canada. Nearest populations of T. minimus in the Rocky Mountains are 80–100 km east along the Continental Divide. They are separated from T. m. selkirki by extensive montane and lowland forests inhabited by T. amoenus and the isolating barrier of the Columbia River in the Rocky Mountain Trench (Nagorsen et al. 2002) T. m. oreocetes inhabits a small area in the Rocky Mountains of Glacier National Park, Montana and the southern Rocky Mountains of Canada. This subspecies appears to be isolated from other subspecies by intervening populations of T. amoenus associated with montane forests. The northern limits of the distribution of T. m. oreocetes in Canada have been contentious. Cowan (1946) and Cowan and Guiguet (1965) suggested that the subspecies was restricted to the extreme

Figure 6. North American distribution of the Least Chipmunk (Tamias minimus) (Taken from Hall 1981).

11

southern Rocky Mountains in the Waterton Lakes–Akamina Pass area. The only potential ecological barrier for north-south dispersal by T. minimus in that region would be the Crowsnest Pass, a wide, low-elevation pass (1360 m) that separates alpine habitats by a 4-km-wide gap where intervening populations of T. amoenus could isolate alpine populations of T. minimus. However, most researchers (Crowe 1943; Banfield 1958; Meredith 1975, 1977; Nagorsen et al. 2002) consider the range of T. m. oreocetes to extend along the Continental Divide as far north as Banff and Yoho National Parks (Figure 7) where it is separated from T. m. borealis to the north by the Bow River and Kicking Horse Pass and intervening low-elevation populations of T. amoenus. Because it is restricted to inaccessible alpine areas, few locations records exist for this subspecies in British Columbia (Appendix 1). Nevertheless, except for low passes, T. m. oreocetes probably ranges throughout the entire alpine of the Continental Divide. It also could inhabit alpine areas west of the Flathead River in British Columbia.

Figure 7. Distribution of the Least Chipmunk subspecies T. m. oreocetes and T. m. selkirki in British Columbia. Taken from Nagorsen et al. (2002); map by Ian Parfitt, Columbia Fish and Wildlife Compensation Program.

12

5 POPULATION SIZE AND TRENDS Population density estimates are not available for T. m. oreocetes or T. m. selkirki. Sheppard (1965) noted that T. m. oreocetes had smaller population densities than T. amoenus in the southern Rocky Mountains of Alberta, but provided no quantitative data. Density estimates of the Least Chipmunk in other regions range from 0.3 to 22.2 animals per hectare. Although the population varied seasonally with recruitment of the young, Sheppard (1965) found that T. m. oreocetes populations were stable during the two years of his study. In the wild, average life spans for the Least Chipmunk are about 0.7 years (Verts and Carraway 2001). Sheppard (1965) reported survival rates of 20–30% for juvenile T. m. oreocetes and about 82% for adults. T. minimus has been documented to live up to six years in captivity (Criddle 1943). Causes of mortality have not been documented. Potential predators of T. m. oreocetes and T. m. selkirki include diurnal raptors and mammalian predators such as the Ermine (Mustela erminea), Long-tailed Weasel (Mustela frenata), and Coyote (Canis latrans). The total population size and the number of mature individuals of T. m. oreocetes and T. m. selkirki cannot be determined. No data exist on population trends. Their area of occupancy is unknown, and no habitat suitability models have been developed for either race. There is no evidence of habitat declines.

6 LIMITING FACTORS AND THREATS Although these subspecies are adapted to alpine environments, they probably can survive in forested habitats. Their restriction to the alpine results from competitive exclusion effects with T. ruficaudus and T. amoenus. Threats and limiting factors are few. Because they associated with krummholz and talus habitats above treeline, neither subspecies is affected by forest fire or forest harvesting. The Least Chipmunk is adaptable to human activity, including disturbances from ski developments and backcountry camping/hiking in alpine areas. The only conceivable threat to T. m. oreocetes is open pit coal mines along the Continental Divide in the Rocky Mountains. According to the map of coalfields in the Southern Rocky Mountain Management Plan (British Columbia Ministry of Sustainable Resource Management 2003), most of the coalfields are outside the known distribution and elevation range of this chipmunk (Figure 8). The only area in British Columbia where coalfields are within the potential range of T. m. oreocetes is south of Crowsnest Pass. This area represents an insignificant portion of this subspecies’ total range in Canada. The type locality where T. m. selkirki was discovered in 1944 was the site of an active mine (Paradise Mine) operation which had several mine adits for many years (Carl and Hardy 1945), but this chipmunk has evidently persisted at the site for at least 50 years. Currently, there is no active mining in the basin. Nevertheless, all the known T. m. selkirki occurrences in this area are locations with mining claims (Figure 5). Future mining activity with large-scale disturbance of talus due to blasting could impact the small population of T. m. selkirki. The Paradise Mine and its

13

associated road has recently become a popular recreational area for 4x4 and all-terrain vehicles in summer, and snowmobiles in winter. T. m. selkirki is mostly restricted to rocky talus areas (Figure 2) above the open meadows and old road beds where it is unlikely to be affected. Because it hibernates, this chipmunk is not impacted by winter snowmobile activity.

Figure 8. Distribution of T. m. oreocetes and coal fields in the southern Rocky Mountains of British Columbia. Map by Dana Diotte, British Columbia Ministry of Sustainable Resource Management.

14

7 SPECIAL SIGNIFICANCE OF THE SPECIES The Least Chipmunk has the broadest range of any chipmunk in Canada, and in many regions it is a familiar small mammal in campgrounds and parks. However, because they are confined to mostly inaccessible alpine areas above treeline, the T. m. selkirki and T. m. oreocetes subspecies are largely unknown even to most naturalists. According to Sheppard (1965), T. m. selkirki and T. m. oreocetes are the only T. minimus subspecies confined to alpine. The life history and physiological adaptations of these races are of interest in comparative studies with other populations. These subspecies also provide a model for evolutionary processes and historical biogeography in the western Cordillera that needs to be tested with a phylogeographic study of mtDNA. T. m. selkirki is endemic to Canada and British Columbia, and it presumably is a relict population that has been isolated in the Purcell Mountains since the early postglacial. Its affinity with the Rocky Mountain forms is not clear, but T. m. selkirki could represent a separate lineage of T. minimus derived from populations that share a separate phylogeographic history from populations in the Canadian Rocky Mountains and northern boreal forests (Nagorsen et al. 2002). About 40% of the distributional area of T. m. oreocetes occurs in British Columbia, and about 90% of its range is in Canada. It may be derived from T. m. borealis populations that were isolated by expanding forests and the invasion of T. amoenus in the Bow River valley during the early Holocene. Alternatively, T. m. oreocetes may represent a separate lineage that was isolated in mountain refugia south of the Cordilleran ice sheet (Meredith 1975, 1976).

8 EXISTING PROTECTION OR OTHER STATUS Sullivan and Nagorsen (1998) ranked T. minimus as Lower Risk, least concern using the International Union for Conservation of Nature and Natural Resources (IUCN) criteria, but they considered two subspecies to be at risk. T. m. atristriatus, an isolated subspecies from New Mexico was ranked Critically Endangered; T. m. selkirki was ranked Vulnerable. Both subspecies are listed in the current IUCN Red Book. T. minimus has not been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Globally, the species' heritage ranking is G5 (secure); in Canada, it is listed nationally as N5 (secure). T. m. selkirki is listed by the British Columbia Conservation Data Centre as S1S3 (critically imperilled to vulnerable), and T. m. oreocetes is listed as S2S3 (imperilled to vulnerable). The subspecies T. m. oreocetes is not listed by Montana or Alberta, the other jurisdictions within its range. In British Columbia, T. minimus is protected from killing under the provincial Wildlife Act. However, its habitat is only protected in provincial or national parks and ecological reserves. Neither T. m. oreocetes nor T. m. selkirki are listed as an Identified Wildlife Species by the province, and, therefore have no protection under the revised British Columbia Forest Practices Code.

15

None of the known range of T. m. selkirki is in a protected area. The Purcell Wilderness Conservancy (1063 km2) is only 18 km south of the range, but no small mammal inventories have done in this protected area. Much of the range of T. m. oreocetes is within national and provincial protected areas. A series of parks along the Continental Divide in British Columbia encompass its range: Akamina-Kishinena Provincial Park (109 km2), Elk Lake Provincial Park (173 km2), Height of the Rockies Provincial Park (680 km2), Mount Assiniboine Provincial Park (390 km2), Kootenay National Park (1406 km2), and Yoho National Park (1310 km2). The proportion of these protected areas that support T. m. oreocetes habitat has not been calculated. A series of provincial and national parks in Alberta, including Banff National Park, Waterton Lakes National Park, and the Kananaskis Recreational Area encompass the Alberta range. In Montana, this subspecies is confined to Glacier Lake National Park.

9 RECOMMENDATIONS AND MANAGEMENT OPTIONS

9.1 Inventory Because their range is restricted to mostly inaccessible alpine areas, both subspecies have been poorly inventoried. Most of the known occurrences are from parks or alpine areas that are accessible by mining or logging roads. A thorough survey of the British Columbian range would require helicopter support. The most critical need is for more inventory in the Purcell Mountains to delimit the precise range of T. m. selkirki. Important issues are this subspecies’ presence in the Purcell Wilderness Conservancy and to what extent the Springs Creek and Mount Brewer occurrences are isolated subpopulations. Chipmunk surveys in alpine areas of the Selkirk Mountains are required to verify that T. minimus is absent from this adjacent mountain range. Developing a habitat model and GIS analysis would assist in defining potential habitats and areas for future inventory work. The few known records of T. m. oreocetes in British Columbia are from the Continental Divide. Potential alpine habitat exists in some of the mountains on the west side of the Flathead and Elk River valleys, areas that have not been inventoried (see Nagorsen et al. 2002). A GIS analysis overlaying the known distribution of this chipmunk with coalfields and coal leases in the Rocky Mountains would be useful.

9.2 Habitat Protection and Acquisition T. m. oreocetes is well protected in British Columbia by a series of national and provincial parks. No protected areas are within the known range of T. m. selkirki. A comprehensive inventory of the Purcell Wilderness Conservancy is essential before any habitat acquisition is considered. Future mining development and off-road vehicle activity in the Paradise Mine area should be carefully monitored for possible impacts on the subpopulation of T. m. selkirki inhabiting this basin.

16

10 EVALUATION

10.1 Provincial Ranking Until more taxonomic research is done to resolve the taxonomic validity of T. m. oreocetes and T. m. selkirki, it is recommend that they be considered nationally significant populations that warrant separate rankings.

10.1.1 T. m. oreocetes (see Appendix 2)

Originally ranked S1S3 by Cannings et al. (1999), this subspecies is currently listed as S2S3 (Blue List) by the British Columbia Conservation Data Centre, largely on the basis of its small distributional area and few known occurrences. This subspecies has not been listed by the Natural Heritage Information Centres of Alberta or Montana. Although there are no reliable data on population numbers or trends, this subspecies is not at risk because of its presumed continuous range along the Continental Divide, and potential rescue effects from populations in Montana and across the Continental Divide between British Columbia and Alberta. There are no known threats other than habitat loss from open pit coal mines. However, most of the coalfields in the Rocky Mountains of British Columbia are below the elevational range of T. m. oreocetes. Any impacts from open pit mining are probably offset by the protection of much of this subspecies' range in British Columbia and Alberta in the national and provincial park systems of the southern Rocky Mountains. Number of Subpopulations: None. Number of Occurrences: Using the recommended separation distance criteria of 1 km, the number of known occurrences for the British Columbian range is estimated at about 10 (Appendix 1). Population Size: The current population size and number of mature individuals in British Columbia are unknown. Population Trends: No data are available on population trends. Population density fluctuates seasonally. There is no evidence of declines in suitable habitat. Extent of Occurrence: The extent of occurrence is about 1800 km2. The British Columbian range represents about 40% of the distributional area of this subspecies; about 90% of this subspecies’ range is in Canada. Area of Occupancy: The area of occupancy is unknown.

17

Threats: There are no obvious threats to this subspecies. The only conceivable threat is destruction of habitat from open pit coal mines. Scope: insignificant, < 5% of the area affected Severity: moderate, reduction of habitat in area affected Imminence: high, threat is operational Environmental Specificity: Medium-generalist with some key requirements (talus or krummholz) scarce or patchily distributed. Number of Protected Occurrences: Of the known occurrences in British Columbia, five are within the boundaries of protected areas. Much of the British Columbia range of this subspecies is within the boundaries of national and provincial parks: Akamina-Kishinena Provincial Park, Elk Lake Provincial Park, Height of the Rockies Provincial Park, Mount Assiniboine Provincial Park, Kootenay National Park, and Yoho National Park. Intrinsic Vulnerability: Not intrinsically vulnerable.

10.1.2 T. m. selkirki (see Appendix 3) Sullivan and Nagorsen (1998) ranked this taxon as Vulnerable D2 with the IUCN criteria based on its restricted range and area of occupancy of less than 100 km2. When Sullivan and Nagorsen (1998) did their assessment, T. m. selkirki was known only from historical museum records collected from the type locality at the Paradise Mine. Moreover, their designation was based on the old IUCN criteria (version 2.3, 1994). Even with new occurrence records from recent field studies (Nagorsen et al. 2002), and applying the revised IUCN criteria (version 3.1, 2001), this subspecies would still be ranked as Vulnerable D1. Nevertheless, no threats have been identified other than stochastic extinction events associated with small isolated populations. Large-scale mining operations could also impact this subspecies. Provincially, T. m. selkirki is ranked S1S3 (Red List) because of the few occurrences (Cannings et al. 1999). Number of Subpopulations: Based on the existing distributional data, the Springs Creek basin and Mount Brewer occurrences qualify as two subpopulations. Number of Occurrences: Using the recommended separation distance criteria of 1 km, the number of known occurrences for the British Columbia range is estimated at about 5 (Appendix 1). The number of occurrences with good viability is unknown.

18

Population Size: The current population size and number of mature individuals in British Columbia are unknown. However, the number of mature animals is probably no more than 250–500. Population Trends: No data are available on population trends. Population density fluctuates seasonally. There is no evidence of declines in suitable habitat, and this subspecies has persisted at the Paradise Mine for at least 50 years. Extent of Occurrence: The known extent of occurrence is about 30 km2. Area of Occupancy: The area of occupancy is unknown, but based on the known occurrences, it would be about 10 km2. Threats: The only potential threat to this subspecies is stochastic effects from small population size and future mining activity. Scope: moderate, 20–60% of the area affected Severity: low Imminence: low or insignificant Environmental Specificity: Medium-generalist with some key requirements (talus or krummholz) scarce or patchily distributed. Number of Protected Occurrences: Of the five known occurrences, none occur in protected areas. Intrinsic Vulnerability: Moderately vulnerable because of its distribution in small subpopulations.

10.2 COSEWIC Ranking The Least Chipmunk has not been assessed by COSEWIC. Because the entire Canadian range of T. m. selkirki occurs in British Columbia, data in this report could be applied to make a COSEWIC assessment. However, any COSEWIC assessment of T. m. oreocetes must include data from the Alberta population. The technical summary for T. m. oreocetes (Appendix 2) in this report is based only on the British Columbia population. For a national COSEWIC status assessment, categories such as extent of occurrence and number of extant locations must include the entire Canadian range.

T. m. oreocetes does not qualify for Endangered or Threatened status. Despite its British Columbia provincial listing as S2S3, the lack of any threats and its protection in a number of

19

provincial and national parks may preclude this subspecies being designated as Special Concern. However, data on its distribution and potential threats in Alberta need to be assessed before this taxon is ranked as Not at Risk.

Although there is no evidence of population or habitat declines in T. m. selkirki, this subspecies may qualify as Threatened. There is no potential for rescue. It is known from only two general locations in the Purcell Mountains, has an area of occupancy less than 100 km2, consists of less than 1000 mature animals, and is isolated with no potential for rescue. These criteria would qualify T. m. selkirki as a candidate for Threatened under the COSEWIC criteria D1.

11 AUTHORITIES CONSULTED Antifeau, Ted. Rare and Endangered Species Biologist, B.C. Ministry of Water, Air and Land

Protection, 401-333 Victoria Street, Nelson, BC V1L 4K3. Tel: (250) 354-6163. Email: [email protected]

Demboski, John. Biological Sciences Department, California State Polytechnic University, 301 Temple Avenue, Pomona, CA, 91796-4032, USA. Email: [email protected].

Good, Jeff. Graduate Student, Department of Ecology and Evolutionary Biology, University of Arizona, Biosciences West, Tucson, AZ 85721. Email: [email protected]

Grieve, Dave. Mineral Land Planner, B.C. Ministry of Sustainable Resources Management, 205 Industrial Road G, Cranbrook, BC V1C 7G5. Tel: (250) 489-8514. Email: [email protected]

Guy, Stewart. Project Manager, Wildlife Conservation Planning, B.C. Ministry of Water, Land and Air Protection. PO Box 9338 Stn Prov Govt, Victoria, BC V8W 9M1. Tel: (250) 387-0060. Email: [email protected].

Fraker, Mark. Consultant, TerraMar Environmental Research Ltd., Sidney, BC V8L 1M8. Tel: (250) 656-3972. Email: [email protected]

Krebs, John. Wildlife Biologist, Columbia Basin Fish and Wildlife Compensation Program, 401-333 Victoria Street, Nelson, BC V1L 4K3. Tel: (250) 352-6874. Email: [email protected]

McTaggart-Cowan, Ian. 3919 Woodhaven Terrace, Victoria, BC V8N 1S7. Tel: (250) 477-7798. Ramsay, Leah. B.C. Ministry of Sustainable Resources Management, Conservation Data Centre,

PO Box 9344 Stn Prov Govt, Victoria, BC V8W 9M1. Tel: (250) 387-9524. Email: [email protected]

12 LITERATURE CITED Anderson, R.M. 1946. Catalogue of Canadian recent mammals. Nat. Mus. Can. Bull. 102:1–238. Banfield, A.W.F. 1958. The mammals of Banff National Park, Alberta. Nat. Mus. Can. Bull.

159:1–53. Bihr, K.J., and R.J. Smith. 1998. Location, structure, and contents of burrows of Spermophilus

lateralis and Tamias minimus, two ground dwelling sciurids. Southwest. Nat. 43:352–362.

British Columbia Ministry of Sustainable Resource Management. 2003. Southern Rocky Mountain Management Plan. Public Review Draft, February 14, 2003. Victoria, B.C. 111pp. + maps.

Broadbrooks, H.E. 1974. Tree nests of chipmunks with comments on associated behavior and ecology. J. Mammal. 55:630–639.

20

mailto:[email protected]






Cannings, S.G., L.R. Ramsay, D.F. Fraser, and M.A. Fraker. 1999. Rare amphibians, reptiles, and mammals of British Columbia. B.C. Minist. Environ., Lands and Parks, Wildl. Branch and Resour. Inventory Branch, Victoria, B.C. 198pp.

Carl, C.G., and G.A. Hardy. 1945. Flora and fauna of the Paradise Mine area. Report of the Provincial Museum1944. B.C. Prov. Mus., Victoria, B.C. pp. C18–C38.

Chappell, M.A. 1978. Behavioral factors in the altitudinal zonation of chipmunks Eutamias. Ecology 59:565–579.

Cowan, M. 1946. Notes on the distribution of the chipmunks Eutamias in southern British Columbia and the Rocky Mountain region of southern Alberta with descriptions of two new races. Proc. Biol. Soc. Wash. 59:107–118.

Cowan, M., and C.J. Guiguet. 1965. The mammals of British Columbia. B.C. Prov. Mus., Victoria, B.C. 414pp.

Cowan, M., and J.A. Munro. 1945. Birds and mammals of Revelstoke National Park. Can. Alpine J. 29:100–121.

Criddle, S. 1943. The little northern chipmunk in southern Manitoba. Can. Field-Nat. 57:81–86. Crowe, P.E. 1943. Notes on some mammals of the southern Canadian Rocky Mountains. Am.

Mus. Nat. Hist. Bull. 80:391–410. Hall, E.R. 1981. The mammals of North America. John Wiley and Sons, New York, N.Y. 601-

1181+90pp. Hoffmann, R.S. 1974. Terrestrial vertebrates. Pp. 475–568 in J.D. Ives and G.B. Roger, eds.

Arctic and alpine environments. Methuen and Company Limited, London, 999pp. Howell, A.H. 1922. Diagnoses of seven new chipmunks of the genus Eutamias, with a list of

American species. J. Mammal. 3:178–185. Howell, A.B. 1929. Revision of the American chipmunks. North Am. Fauna 52:1–157. Jameson, E.W.J. 1999. Host-ectoparasite relationships among North American chipmunks. Acta

Theriologica 44:225–231. Jones, D.L., and L.C.H. Wang. 1976. Metabolic and cardiovascular adaptations in the western

chipmunks, genus Eutamias. J. Comp. Physiol. 105:219–231. Meredith, D.H. 1974. Long distance movements of two species of chipmunks Eutamias in

southern Alberta. J. Mammal. 55:466–469. Meredith, D.H. 1975. Habitat selection and interspecific agonism in two parapatric species of

chipmunks (Eutamias). Ph.D.Thesis, Univ. Alberta, Edmonton, Alta. 95pp. Meredith, D.H. 1976. Habitat selection by two parapatric species of chipmunks Eutamias. Can. J.

Zool. 54:536–543. Meredith, D.H. 1977. Interspecific agonism in two parapatric species of chipmunks, Eutamias.

Ecology 58:423–430. Merriam, C.H. 1897. Notes on the chipmunks of the genus Eutamias occurring west of the east

base of the Cascade–Sierra system. Proc. Biol. Soc. Wash. 11:189–212. Nagorsen, D.W. 2002. An identification manual to the small mammals of British Columbia. B.C.

Minist. Sustainable Resour. Manag.; B.C. Minist. Water, Land, and Air Prot., and R.B.C. Mus. 153pp.

Nagorsen, D.W., N. Panter, and M.A. Fraker. 2002. Chipmunks of the Kootenay region, British Columbia: Distribution, identification, taxonomy, conservation status. Columbia Basin Fish and Wildlife Compensation Program, Nelson, B.C. 142+viii pp. [http://www.cbfishwildlife.org/reports/chipmunk_pdfs.php]

Panian, M.A. 1996. Chipmunks in the Kootenays: red-tailed chipmunk subspecies simulans. Columbia Basin Fish and Wildlife Compensation Program, Nelson. 69pp. [http:/srmwww.gov.bc.ca/kor/wld/reports/zipfiles/chip.zip]

Piaggio, A.J., and G.S. Spicer. 2000. Molecular phylogeny of the chipmunk genus Tamias based on the mitochondrial cytochrome oxidase subunit gene. J. Molecular Evol. 7:147–166.

21

22

Piaggio, A.J., and G.S. Spicer. 2001. Molecular phylogeny of chipmunks inferred from mitochondrial cytochrome b and cytochrome oxidase II gene sequences. Molecular Phylogenetics and Evolution 20:335–350.

Pivorun, E.B. 1976. A biotelemetry study of the thermoregulatory patterns of Tamias striatus and Eutamias minimus during hibernation. Comp. Biochem. Physiol. A Physiol. 53:265–271.

Sheppard, D.H. 1965. Ecology of the chipmunks Eutamias amoenus luteiventris (Allen) and E. minimus oreocetes Merriam, with particular reference to competition. Ph.D. Thesis, Univ. Saskatchewan, Saskatoon, Sask. 229pp.

Sheppard, D.H. 1969. A comparison of reproduction in two chipmunk species (Eutamias). Can. J. Zool. 47:603–608.

Sheppard, D.H. 1971. Competition between two chipmunk species Eutamias. Ecology 52:320–329.

Sheppard, D.H. 1972. Home ranges of chipmunks Eutamias in Alberta. J. Mammal. 53:379–380. Smith, R.J. 1995. Harvest rates and escape speeds in two coexisting species of montane ground

squirrels. J. Mammal. 76:189–195. Soper, J.D. 1964. The mammals of Alberta. Hamley Press Limited, Edmonton, Alta. 409pp. Soper, J.D. 1973. The mammals of Waterton Lakes National Park Alberta. Can. Wildl. Serv. Rep.

Ser. 23:1–55. Sullivan, R.M. 1985. Phyletic, biogeographic, and ecologic relationships among montane

populations of least chipmunks (Eutamias minimus) in the southwest. Syst. Zool. 34:419–448.

Sullivan, R.M., and D.W. Nagorsen. 1998. Tamias minimus. Pp 54–55 in D.J. Hafner, E. Yensen, and G.L.J. Kirkland, eds. North American rodents. Status survey and conservation action plan. IUCN Publ., Gland. 171pp.

Sullivan, R.M., and K.E. Petersen. 1988. Systematics of southwestern populations of least chipmunks (Tamias minimus) reexamined: a synthetic approach. Mus. Southwest. Biol., Occas. Pap. 5:1–27.

van Tighem, K.J., and L.W. Gyug. 1984. The ecological land classification of Mount Revelstoke and Glacier National Parks British Columbia. Wildl. Resour. Can. Wildl. Serv., Edmonton, Alta. 245pp.

Verts, B.J., and L.N. Carraway. 2001. Tamias minimus. Mamm. Species 653:1–10. Wallis, C., and C. Wershler. 1997. Waterton Lakes National Park ecological land classification

(wildlife component) 1995–96. Unpublished report. Canadian Heritage, Calgary, Alta. 195pp.

Willems, N.J., and K.B. Armitage. 1975a. Thermoregulation and water requirements in semiarid and montane populations of the least chipmunk, Eutamias minimus -1. Metabolic rate and body temperature. Comp. Biochem. Physiol. A Physiol. 51:717–722.

Willems, N.J., and K.B. Armitage. 1975b. Thermoregulation and water requirements in semiarid and montane populations of the least chipmunk, Eutamias minimus -2. Water balance. Comp. Biochem. Physiol. A Physiol. 52:109–120.

Willems, N.J., and K.B. Armitage. 1975c. Thermoregulation and water requirements in semiarid and montane populations of the least chipmunk, Eutamias minimus -3. Acclimatization at high ambient temperature. Comp. Biochem. Physiol. A Physiol. 52:121–128.

Wilson, D.E., and D.M. Reeder. 1993. Mammal species of the world. A taxonomic and geographic reference Smithsonian Inst. Press, Washington, D.C. 1206pp.

Appendix 1. Known occurrences of T. m. oreocetes and T. m. selkirki in British Columbia based on museum specimens and literature records. Source1 Park Location Northing Easting Elevation

(m) T. m. oreocetes Cowan & Guiguet (1965)

Akamina-Kishinena Prov Park

Akamina Pass 5434000.00 715000.00 -

19358 RBCM Yoho National Park Burgess Pass; N of 5698750.00 536300.00 2228 19360 RBCM Yoho National Park Burgess Pass 5698700.00 536650.00 2305 19361 RBCM Yoho National Park Burgess Pass 5698700.00 536650.00 2305 19362 RBCM Yoho National Park Burgess Pass 5698700.00 536650.00 2305 Poll et al. (1984) Kootenay National

Park Goodsir Pass 5673500.00 548000.00 2200?

19872 RBCM Middle Kootenay Pass; Rainy Ridge; Site 004

5459072.00 688992.00 1950


5458999.00 689019.00 1950


5458999.00 689019.00 1950


5459072.00 688992.00 1950

19883 RBCM Middle Kootenay Pass; Rainy Ridge;Site 004

5459147.00 689014.00 1950

19909 RBCM Middle Kootenay Pass; Site 002

5459805.00 688736.00 1945

19908 RBCM Middle Kootenay Pass; Site 003

5459805.00 688736.00 1945

19912 RBCM Middlepass Creek; 200m above Source; Site 007

5457802.00 689813.00 2090

19913 RBCM Middlepass Creek; 00m Above Source; Site 007

5457802.00 689813.00 2090

19911 RBCM Middlepass Creek; 300m Below Source; Site 006

5458088.00 689512.00 2055

141669 AMNH Kootenay National Park

Monarch Mountain 5654000.00 586000.00 2196









141674 AMNH Mount Assiniboine Prov Park

Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318

23


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318


Sunburst Lake 5641000.00 596000.00 2318

19890 RBCM Todhunter Creek; N Ridge of Mt. Lyall; Site 014

5552018.00 663000.00 2180


5552018.00 663000.00 2180


5552018.00 663000.00 2180


5551959.00 662894.00 2180


5551927.00 663062.00 2180

24

25

124975 AMNH Tornado Pass 5541000.00 666000.00 2135 124976 AMNH Tornado Pass 5541000.00 666000.00 2135 124980 AMNH Tornado Pass 5541000.00 666000.00 2135 124981 AMNH Tornado Pass 5541000.00 666000.00 2135 124983 AMNH Tornado Pass 5541000.00 666000.00 2135 124984 AMNH Tornado Pass 5541000.00 666000.00 2135 124987 AMNH Tornado Pass 5541000.00 666000.00 2135 124989 AMNH Tornado Pass 5541000.00 666000.00 2135 124991 AMNH Tornado Pass 5541000.00 666000.00 2135 Poll et al. (1984) Kootenay National

Park Vermilion Pass; Burn 5675000.00 566300.00 2200?

T. m. selkirki 19924 RBCM Bruce Creek Drainage; Site

010 5592372.00 550007.00 2280

19925 RBCM Bruce Creek Drainage; Site 010

5592372.00 550007.00 2295

19755 RBCM Mount Brewer; Site Ksm113 5583043.00 554976.00 2230 19758 RBCM Mount Brewer; Site Ksm115 5582768.00 555275.00 2185 19762 RBCM Mount Brewer; Site Ksm115 5582768.00 555275.00 2185 19761 RBCM Mount Brewer 5582102.00 555341.00 2365 19760 RBCM Mount Brewer; Ridge Top;

Site Ksm117 5582153.00 554867.00 2380

19765 RBCM Mount Brewer; Ridge Top; Site Ksm117

5582153.00 554867.00 2380

19754 RBCM Mount Brewer; Unnamed Peak NE; Site Ksm112

5579675.00 560488.00 2305

34512 CMN Paradise Mine; 19 Mi W Invermere

5591100.00 549600.00 -

151303 MVZ Paradise Mine; 30 Km W Invermere

5591100.00 549600.00 2134

1552 UBC Paradise Mine; 30 Km W Invermere

5577000.00 540000.00 -

1553 UBC Paradise Mine; 30 Km W Invermere

5577000.00 540000.00 -

19740 RBCM Paradise Mine 5591623.00 549210.00 2300 5028 RBCM Paradise Mine; Near

Invermere 5591100.00 549600.00 2134

5029 RBCM Paradise Mine; Near Invermere

5591100.00 549600.00 2134

19741RBCM Springs Creek; Basin Head of; Site Ksm106

5590529.00 549090.00 2335

19743 RBCM Springs Creek; Basin Head of; Site Ksm107

5590509.00 548995.00 2305


5590529.00 549090.00 2305


5590694.00 548934.00 2305

1 AMNH=American Museum of Natural History, New York; CMN=Canadian Museum of Nature, Ottawa; MVZ=Museum of Vertebrate Zoology, University of California, Berkeley; RBCM=Royal British Columbia Museum, Victoria; UBC=University of British Columbia; Vancouver

Appendix 2. Technical Summary - Tamias minimus oreocetes Least Chipmunk–Timberline subspecies Alberta, British Columbia Extent and Area Information • extent of occurrence (EO)(km²) 18001 • specify trend (decline, stable, increasing,

unknown) Stable

• are there extreme fluctuations in EO (> 1 order of magnitude)?

No

• area of occupancy (AO) (km²) Unknown • specify trend (decline, stable, increasing,

unknown) -

• are there extreme fluctuations in AO (> 1 order magnitude)?

-

• number of extant locations 102 • specify trend in # locations (decline, stable,

increasing, unknown) Stable

• are there extreme fluctuations in # locations (>1 order of magnitude)?

No

• habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat

Stable

Population Information • generation time (average age of parents in the population)

(indicate years, months, days, etc.) 2 years

• number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values)

Unknown

• total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals

Stable

• if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period)

-

• are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?

-

• is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., < 1 successful migrant/year)?

No

• list each population and the number of mature individuals in each

-

• specify trend in number of populations (decline, stable, increasing, unknown)

-

• are there extreme fluctuations in number of populations (>1 order of magnitude)?

-

Threats (actual or imminent threats to populations or habitats) -open pit coal mines Rescue Effect (immigration from an outside source) Moderate

26

• does species exist elsewhere (in Canada or outside)? Yes • status of the outside population(s)? Not at Risk • is immigration known or possible? Yes • would immigrants be adapted to survive here? Yes • is there sufficient habitat for immigrants here? Yes 2.1 Quantitative Analysis - David Nagorsen, January 2003 1 For British Columbia portion of range only 2 Number of element occurrences in British Columbia portion of range only, some historical

27

Appendix 3. TECHNICAL SUMMARY - Tamias minimus selkirki Least Chipmunk–Selkirk subspecies British Columbia Extent and Area Information • extent of occurrence (EO)(km²) 30 • specify trend (decline, stable, increasing,

unknown) Stable

• are there extreme fluctuations in EO (> 1 order of magnitude)?

No

• area of occupancy (AO) (km²) 10 • specify trend (decline, stable, increasing,

unknown) Stable

• are there extreme fluctuations in AO (> 1 order magnitude)?

No

• number of extant locations 5 • specify trend in # locations (decline, stable,

increasing, unknown) Stable

• are there extreme fluctuations in # locations (>1 order of magnitude)?

No

• habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat

Stable

Population Information • generation time (average age of parents in the population)

(indicate years, months, days, etc.) 2 years

• number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values)

200–250

• total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals

Stable

• if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period)

-

• are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?

-

• is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., < 1 successful migrant/year)?

Yes 2 subpopulations

• Springs Creek Basin • Mount Brewer

150? 100?

• specify trend in number of populations (decline, stable, increasing, unknown)

No

• are there extreme fluctuations in number of populations (>1 order of magnitude)?

No

Threats (actual or imminent threats to populations or habitats) -stochastic effects from small isolated population

28

29

Rescue Effect (immigration from an outside source) Low • does species exist elsewhere (in Canada or outside)? No • status of the outside population(s)? - • is immigration known or possible? No • would immigrants be adapted to survive here? - • is there sufficient habitat for immigrants here? - Quantitative Analysis - David Nagorsen, January 2003

Documents

Status of the Red-tailed Chipmunk (Tamias ruficaudus) in ... · Chipmunk (Tamias amoenus) and Red-tailed Chipmunk (Tamias ruficaudus), larger chipmunks that exclude the Least Chipmunk