BC Conservation Data Centre: Conservation Status Report
Lagopus leucura saxatilis
White-tailed Ptarmigan, saxatilis subspecies
| Scientific Name: | Lagopus leucura saxatilis |
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| Scientific Name Synonyms: |
Lagopus leucurus saxatilis
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| English Name: | White-tailed Ptarmigan, saxatilis subspecies |
| Provincial Status Summary | |
| Status: | S3S4 |
| Date Status Assigned: | March 30, 2018 |
| Date Last Reviewed: | March 30, 2018 |
| Reasons: | This subspecies is at risk due to its small population size and its local distribution within a restricted range. The "Vancouver Island" White-tailed Ptarmigan appears to occupy most, if not all, suitable habitat, and its distribution does not seem to have shifted from historic occurrences (Martin et al. 2004). The shortage of observations and lack of population and density estimates can partly be explained by difficult access to its restricted habitats and the cryptic nature of the bird (Campbell et al. 1990; Jackson et al. 2015b). |
| Range | |
| Range Extent: | E = 5,000-20,000 square km |
| Range Extent Estimate (km2): | 8,943 |
| Range Extent Comments: | Restricted to high mountains of Vancouver Island from Tsitika Mtn in the north to Mt. Brenton in the south (Martin et al. 2004). No known change in distribution from first-half of 20th century to early 2000s (Martin et al. 2004). The majority (=90%) of locations are within the Alpine Tundra BEC zone, with the rest in the Mountain Hemlock zone (Jackson et al. 2015). |
| Area of Occupancy (km2): | E = 26-125 |
| Area of Occupancy Estimate (km2): | 56 |
| Area of Occupancy Comments: | The Vancouver Island White-tailed Ptarmigan is restricted to breeding in alpine habitats, which are patchily distributed along Vancouver Island. Area of occupancy estimated based on work by Martin et al. (2004) and citizen science data at 56 4-km squared cells. Across its range, breeding densities range from <1 to 13.5 birds/km2 (Martin et al. 2015). Density average 2-6 birds/km2 in the Yukon (Wilson and Martin 2008). No data available on breeding densities for Vancouver Island ptarmigan. Jackson et al. (2015a) estimate suitable habitat encompasses 521 km2. |
| Occurrences & Population | |
| Number of Occurrences: | C = 21 - 80 |
| Comments: | Vancouver Island ptarmigan have been documented from at least 78 alpine sites (Martin et al. 2004). The core range is on central Vancouver Island. Because White-tailed Ptarmigan are cryptic and occupy difficult to access areas, they may be present everywhere on Vancouver Island where suitable alpine habitat exists. The BC Breeding Bird Atlas had detections in 10 map squares: 2 confirmed, 1 probable, 7 possible breeding occurrences (Martell 2015). Campbell et al. (1990) listed 23 observations and 8 breeding records for this subspecies; acknowledging the paucity of records was likely due to the inherent difficulty of accessing and finding ptarmigan. |
| Number of Occurrences with Good Viability / Ecological Integrity: | DE = 13 - 125 |
| Comments: | Vancouver Island ptarmigan populations appear to have persisted without noticeable change from historical records (Martin et al. 2004). The core population on central Vancouver Island (e.g., in Strathcona Park) is protected, and is benefited by more extensive suitable alpine habitat. Populations on southern Vancouver Island are likely less sustainable over longer terms (Jackson et al. 2015a). |
| Number of Occurrences Appropriately Protected & Managed: | C = 4 - 12 |
| Comments: | Several provincial and regional parks protect suitable habitat within this subspecies range. A core portion of the total population, and the most suitable alpine habitat, is protected within Strathcona Provincial Park (Martin and Forbes 2001, Jackson et al. 2015b). Mount Arrowsmith Massif Regional Park (RDN), Mount Arrowsmith Regional Park (ACRD), Clayoquot Plateau Provincial Park, and Woss Lake Provincial Park all include some alpine habitat with known ptarmigan occurrence. |
| Population Size: | C = 250 - 1,000 individuals |
| Comments: | Population size has not been estimated (Martin and Forbes 2001). Relative abundance data has proven challenging to collect, as detection probabilities are influenced by access constraints, observer experience, weather, and other factors (Martin et al. 2004). Suitable habitat has been estimated to encompass 521 km2 (Jackson et al. 2015a). In Colorado, a breeding density of 6 birds/km2 has been used to estimate ptarmigan populations (Hoffman 2006). Assuming similar breeding densities as the Yukon (2-6 birds/km2 [Wilson and Martin 2008]) results in a population estimate of 1,042-3,072 birds on Vancouver Island. In one study on central and southern Vancouver Island, 179 adults and 72 yearlings were tagged between 1995 and 2004 (Fedy and Martin 2011). Thus, the population is likely in the hundreds to low thousands, but not currently quantified. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | Rank Factor not assessed |
| Comments: | Climate change is major long-term threat leading to a signficant and permanent loss of habitat over the next several decades (Hoffman 2006; Jackson et al. 2015a). Impacts of many potential threats (recreational activities, forestry, contaminants) are unquantified, leading to uncertainty in their severity, but are believed to all be secondary to climate-induced reduction of suitable breeding habitat. The subspecies is resident on Vancouver Island and is believed to occur at low densitives and with a relatively small population size. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | G = Relatively Stable (<=10% change) |
| Comments: | No data are available on population trends. However, there is no evidence that populations are currently decreasing. As suitable breeding habitat is limited, it is also unlikely that the population will be able to increase, unless areas of unoccupied habitat exist. Where data exist elsewhere in this species range, populations are believed to be overall stable despite high annual variation in population size (Martin et al. 2015). No declines in species range or occurrence have been reported from Vancouver Island. This species is not surveyed by traditional population surveys, such as the Breeding Bird Survey or Christmas Bird Counts. |
| Long-Term Trend: | G = Relatively Stable (<=10% change) |
| Comments: | No data are available on population trends. There has been no known change in distribution on Vancouver Island, and it is believed to occupy most, or all, of the available habitat on Vancouver Island (Martin et al. 2004). Based on this, and evidence from elsewhere in the species range that suggests overall stable populations (Martin et al. 2015), the long-term trend is believed to be stable. |
| Other Factors | |
| Intrinsic Vulnerability: | B=Moderately vulnerable |
| Comments: | Vancouver Island White-tailed Ptarmigan are vulnerable to population declines or local extirpations given their specific and limited breeding habitat (alpine areas), low densities, and environmental stochasticity (Martin and Forbes 2001). Important demographic attributes including the population size are still unknown on Vancouver Island. They are resident on Vancouver Island, and mostly confined to high elevation areas in the alpine and upper montane forests. They are at risk of habitat loss due to climate change (Jackson et al. 2015a). Despite this, they are resilient to variable environmental conditions, and persist even in the face of low densities, low survival, and low fecundity (see Martin et al. 2015). Generation time is estimated at two to three years (Wilson and Martin 2012; Sandercock et al. 2005). Annual survival rates for the species on Vancouver Island ranged from 0.41 to 0.77 (Martin et al. 2015). |
| Environmental Specificity: | B=Narrow. Specialist or community with key requirements common. |
| Comments: | Vancouver Island White-tailed Ptarmigan occupy high alpine and subalpine habitats year-round. During the breeding season ptarmigan utilize alpine and subalpine heather communities, with or without low densities of spruce and subalpine fir (Martin et al. 2004). While some individuals remain near their breeding range year-round, others move into montane mountain hemlock communities (Martin et al. 2004). They are limited to above ~822 m on Vancouver Island, and one of the few vertebrate species that occurs in this zone year-round (Martin and Forbes 2001; Martin et al. 2004). They rely on permanent snowfields for thermoregulation, camouflage, and forage (Johnson 1968; Fedy and Martin 2011; Jackson et al. 2015a). Such habitats are limited on Vancouver Island, and concentrated around central Vancouver Island. High fidelity to mates, breeding territories, and wintering sites have been documented elsewhere in this species range, especially for males (Hoffman 2006; Martin et al. 2015). Forages mainly from ground on plants (buds, leaves, twigs, seeds, fruits) and invertebrates. On Vancouver Island females with young select sites based on foraging availability, in proximity to standing water and predator cover (Fedy and Martin 2011). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | Key demographic rates (e.g., survival, fecundity, site fidelity) should be quantified. Population trends are currently unknown, and there is uncertainty in population size. Genetic work should also be conducted to assist in future revisions to subspecies taxonomy in this species. |
| Inventory Needs: | Surveys should be undertaken in high suitability habitats identified by ecosystem mapping, to find new sites and better define population distribution. Detailed inventory of known sites using standardized methods (Resour. Inventory Comm. 1997 #17) is required to determine relative densities and estimate total population size. In stratified representative areas, abundance and relative densities should be monitored at regular intervals (e.g. every 5 years) to monitor population trends. Censuses should be coordinated with inventory efforts for other species in similar habitats (e.g., Vancouver Island Marmot) to reduce access costs. |
| Stewardship | |
| Protection: | The species is listed in the proposed Identified Wildlife Management Strategy under the Forest Practices Code of British Columbia Act. Procedures for the establishment of Wildlife Habitat Areas on critical nesting habitats, and General Wildlife Measures to determine appropriate management practices within established areas should be made available to resource managers. |
| Management: | Public information and education products should be developed to encourage members of the public to report observations of birds in areas on Vancouver Island not currently known to support White-tailed Ptarmigan. Mature forest communities should be left intact as winter range adjacent to known White-tailed Ptarmigan breeding sites. Restrictions on the hunting of White-tailed Ptarmigan on Vancouver Island should be continued. Basic ecological and life history information is required for this subspecies to compare to biological attributes of mainland subspecies of White-tailed Ptarmigan. The potential for timber harvesting to impact winter habitats should be investigated. |
| Version | |
| Author: | N. Hentze, S. Cannings and L. Ramsay |
| Date: | April 26, 2018 |
| References | |
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Braun, C.E., K. Martin, and L.A. Robb. 1993. White-tailed Ptarmigan (Lagopus leucurus). in A. Poole and F. Gill, eds. The Birds of North America, No. 68. Acad. Nat. Sci., Philadelphia, PA, and Am. Ornithol. Union, Washington, DC. 24pp.
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British Columbia Conservation Data Centre. 1997. Bird occurrence records from British Columbia database and Global ranking forms. B.C. Minist. Environ., Lands and Parks, Resour. Inventory Branch, Victoria, BC.
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Campbell, R.W., N.K. Dawe, I. McTaggart-Cowan, et al. 1990b. The Birds of British Columbia Vol. 2: Nonpasserines: Diurnal Birds of Prey through Woodpeckers. Royal British Columbia Museum, Victoria, BC.
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Cannings, R.J. 1998. The Birds of British Columbia - a taxonomic catalogue. B.C. Minist. Environ., Lands and Parks, Wildl. Branch, Victoria, Wildl. Bull. B-86. 266pp.
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Godfrey, W.E. 1986. The Birds of Canada, rev. ed. Natl. Mus. Can., Ottawa, ON. 595pp.
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Laroque, C.P. 1998. Tree invasion in subalpine Vancouver Island Marmot Meadows. Univ. Victoria Tree Ring Lab. Rep. 98-01. Environ. Res. Comm. Victoria, BC. 18pp.
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Resource Inventory Committee. 1997h. Standardized Inventory Methodologies for Components of British Columbia's Biodiversity: Upland Gamebirds, version 1.1. Prepared for the Resource Inventory Committee. Minist. Environ., Lands and Parks, Victoria, BC. 36pp.
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Weeden, R.B. 1967. Seasonal and geographic variation in the foods of adult White-tailed Ptarmigan. Condor 69(3):303-309.
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Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2018. Conservation Status Report: Lagopus leucura saxatilis. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 8, 2026).