|Scientific Name:||Marmota vancouverensis|
|Species Authority:||Swarth, 1911|
|Taxonomic Notes:||Marmota vancouverensis formerly was regarded as a subspecies of M. marmota by some authors. It was recognized as a distinct species by Jones et al (1992), Hoffmann et al. (in Wilson and Reeder 1993), and Thorington and Hoffmann (in Wilson and Reeder 2005).|
|Red List Category & Criteria:||Critically Endangered A2ac; B2ab(i,ii,iv,v); D; E ver 3.1|
|Assessor/s:||Nagorsen, D.W. & NatureServe (Cannings, S. & Hammerson, G.)|
|Reviewer/s:||Amori, G. & Koprowski, J. (Small Nonvolant Mammal Red List Authority)|
Listed as Critically Endangered because in 2004 it was estimated there were only 35 individuals in one location left in the wild, and its area of occupancy is less than 10 km², and there has been extensive clear cutting of its forest habitat. A population reduction of greater than 80% over the past 18 years (3 generations) has been observed. A quantitative analysis gives the probability of extinction of at least 50% in 17.1 years.
|Range Description:||This marmot is endemic to Vancouver Island, British Columbia, Canada. Historical and confirmed modern distribution records are confined to mountains in the central and southern part of the island, with occurrence in natural habitat typically at elevations of 900-1,450 m asl (Nagorsen 1987), although populations in clearcuts may extend to lower elevations. Occurrences are concentrated on a few mountain ridges in the Nanaimo-Cowichan Lake region of Vancouver Island, British Columbia (Vancouver Island Marmot Recovery Team 1990). There is some evidence that marmots have disappeared from some parts of their historical range, but huge areas of potential habitat have never been formally surveyed. Opinion is divided on the likelihood of discovering new, significant populations.|
Native:Canada (British Columbia)
|Range Map:||Click here to open the map viewer and explore range.|
Bryant (2005) reported the following: "Population counts began in 1979 and have continued, with variable coverage and intensity, until the present. Marmots expanded into new habitats created by clearcut logging of high-elevation primary forests during the 1980s; numbers increased to an estimated 300-350 individuals by 1986, with about half of these living in clearcuts (Bryant and Janz 1996). The temporary population expansion was followed by precipitous decline and near-extinction in the wild (Bryant 2000). Fewer than 130 marmots were known to be alive by 2004, including 93 in captivity and about 35 in the wild (unpublished minutes, Vancouver Island Marmot Recovery Team, November 2004)."
Since 1972, the species has been found at 47 sites on 15 mountains (Bryant and Janz 1996). However, only four occurrences are known to be extant.
Population trends are difficult to determine because estimates of numbers and sizes of colonies before the 1970s are not available and only one or two relatively thorough censuses have been done (these only in the central part of the range). Numbers of adults were above average during the early 1980s and were reported as near or below average since 1990 by Bryant and Janz (1996). Recent data indicate a significant decline during the 1990s. Data for 1997 indicated a 60% decline in numbers during the past decade and a similar reduction in geographic range in the last several decades (Bryant et al. 2002).
A thorough and systematic inventory of all of Vancouver Island, especially the western and northern mountains, is needed to determine the actual present status.
|Habitat and Ecology:||
Subalpine herbaceous communities with steep slopes support the largest populations (Nagorsen 1987). Common tree species in these communities are Abies lasiocarpa, Tsuga mertensiana, and Chamaecyparis nootkatensis; shrubs and herbs include Vaccinium spp., Luetkea pectinata, Alnus sinuata, Erigeron peregrinus, Rhododendron albiflorum, Phlox diffusa, Anaphalis margaritacea, Aster foliaceus, Lupinus arcticus, and Pteridium aquilinum (Milko 1984). Preferred lush forb/grass meadows are relatively rare on Vancouver Island; they generally are restricted to steep, south-facing slopes where avalanches and snow creep inhibit the growth of trees (Nagorsen 1987). Fire also creates favourable meadow habitat on subalpine slopes. Most marmot occurrences are on south- and west-facing slopes (Bryant and Janz 1996). Colonies have also been found in coniferous forest, logging clearcut slash, road banks, and cleared ski runs. In fact, half of the world's M. vancouverensis were living in clearcuts in 1997, compared to about 25% in the mid-1980s and none prior to high elevation logging that began in the late 1960s. Individual marmots occasionally take up residence in valley-bottom gardens (Munro 1985).
Marmots prefer areas with sufficient soil for burrowing, and with large rocks or stumps for burrowing under and for lookout sites. Burrows are usually below rocks in or near meadows. Young are born in underground burrows.
M. vancouverensis is colonial. Colonies are relatively small and inhabit small habitat patches. Most are made up of one to three family units, and the average size before the young-of-the-year emerge is about eight individuals (Bryant 1990). Meta-populations of this species consist of a patchwork of colonies, each of which experiences periodic extinctions and recolonizations (Bryant and Janz 1996). Dispersal is a key ingredient of this pattern; the appearance of individual marmots in unusual habitats far from known colonies indicates thatM. vancouverensis is capable of extensive dispersal through forested lands (Munro 1985). Year-to-year persistence of family groups has been measured at 43% in natural sites and at 13% in logging slash sites (Bryant 1990). Most mortality apparently occurs during hibernation. Survivorship varied dramatically from year to year in Bryant's (1990) study, but a small sample size prevented any accurate determination of a mean rate.
Predation on M. vancouverensis has not been studied, but potential predators include Canis lupus, Martes americana, Gulo gulo, Felis concolor, Ursus americanus, Buteo jamaicensis, Aquila chrysaetos, Accipiter gentilis, and Bubo virginianus (Bryant 1990).
Grasses and sedges are the most important food in early spring; forbs make up the bulk of the summer diet. Small fruits are also eaten. Hibernates from early October to early May.
No obvious threats have been identified, although long-term environmental changes, prehistoric hunting, and recent forestry activities could have impacted populations. Predation on so small a population is considered as a significant threat.
Logging activities adjacent to colonies have created temporarily attractive habitat to marmots and have undoubtedly resulted in an increase in marmot populations. Bryant (1990), however, feared that logging clearcuts may be deleterious in the long run; there is evidence that, although they provide attractive summer habitat, they offer poor conditions for successful hibernation. They may thus act as "sinks" preventing dispersing marmots from reaching adjacent mountain ridges (Bryant 1996). This would decrease genetic outcrossing as well as preventing former colony sites from being recolonized. More research is needed. Bryant (1990) concluded that the known population of M. vancouverensis is not viable using existing criteria.
Bryant and Page (2005) concluded that predation was the proximate cause of recent declines in wild Vancouver Island marmot populations, that losses were highly concentrated in late summer, and that previous studies exaggerated the importance of winter mortality. We suggest that high predation rates were associated with forestry and altered predator abundance and hunting patterns.
It is listed as Endangered under the United States Endangered Species Act (23Jan1984) and by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) it is listed as Endangered (01 May 2000).
There is a recovery plan that recommends captive breeding and introductions as a means of restoring the species. One occurrence is partially protected by an Ecological Reserve and a Critical Wildlife Area (Wildlife Management Area).
Key marmot colonies should be protected by designation as Wildlife Management Areas or by landowner agreements. The draft recovery plan (Vancouver Island Marmot Recovery Team 1990) states that "current known population size and distribution, together with available genetic and demographic data, suggest that direct management may be required to reduce the vulnerability of the species to extinction. However, a complete inventory may show intensive management is not essential and therefore a high priority."
Detailed research is needed on dispersal characteristics, hibernacula requirements, and survivorship and reproduction in natural and logging clearcut habitats.
Bryant, A. A. 1990. Genetic variability and minimum viable populations in the Vancouver Island marmot. Ministry of the Environment.
Bryant, A. A. 2000. Relative importance of episodic versus chronic mortality in the decline of Vancouver Island marmots (Marmota vancouverensis). In: L. Darling (ed.), Biology and Management of Species and Habitats at Risk Vol. I: 189-195. Kamloops, British Columbia.
Bryant, A. A. 2005. Reproductive rates of wild and captive Vancouver Island marmots (Marmota vancouverensis). Canadian Journal of Zoology 83: 664-673.
Bryant, A. A. and Janz, D. W. 1996. Distribution and abundance of Vancouver Island marmots (Marmota vancouverensis). Canadian Journal of Zoology 74: 667-677.
Bryant, A. A. and Page, R. E. 2005. Timing and causes of mortality in the endangered Vancouver Island marmot (Marmota vancouverensis). Canadian Journal of Zoology 83: 674-682.
Bryant, A. A., Janz, D. W., Delaronde, M. C. and Doyle, D. D. 2002. Recent Vancouver Island marmot (Marmota vancouverensis) population changes. In: K. B. Armitage and V. U. Rumianstev (eds), Holarctic Marmots as a Factor of Biodiversity, pp. 88-100. ABF Publishing House, Moscow, Russia.
Hafner, D. J., Yensen, E. and Kirkland Jr., G. L. 1998. Status survey and conservation action plan - North American Rodents. IUCN/SSC Rodent Specialist Group, Gland, Switzerland.
Hoffmann, R. S., Anderson, C. G., Thorington Jr., R. W. and Heaney, L. R. 1993. Family Sciuridae. In: D. Wilson and D. M. Reeder (eds), Mammal Species of the World, a Taxonomic and Geographic Reference, pp. 419-465. Smithsonian Institution Press, Washington, DC, USA.
Jones Jr., J. K., Hoffman, R. S., Rice, D. W., Jones, C., Baker, R. J. and Engstrom, M. D. 1992. Revised checklist of North American mammals north of Mexico, 1991. Occasional Papers, Museum of Texas Tech University 146: 1-23.
Milko, R. J. 1984. Vegetation and foraging ecology of the Vancouver Island marmot (Marmota vancouverensis). Thesis, University Victoria.
Munro, W. T., Janz, D. W. Heinsalu, V. and Smith, G. W. 1985. The Vancouver Island marmot: status and management plan. B. C. Ministry of Environment, Wildlife Branch, Victoria, Canada.
Nagorsen, D. W. 1987. Marmota vancouverensis. Mammalian Species 270: 1-5.
Thorington Jr., R. W. and Hoffmann, R. S. 2005. Family Sciuridae. In: D. E. Wilson and D. M. Reader (eds), Mammal Species of the World, pp. 754-818. The John Hopkins University Press, Baltimore, MD, USA.
Wilson, D. E. and Ruff, S. 1999. The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington, DC, USA.
|Citation:||Nagorsen, D.W. & NatureServe (Cannings, S. & Hammerson, G.) 2008. Marmota vancouverensis. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 25 May 2013.|
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