COSEWIC Wildlife Species Assessments (detailed version), November 2015

Results are grouped by taxon and then by status category. The range of occurrence in Canada (by province, territory or ocean) and history of status designation are provided for each wildlife species.

Mammals

Gray Fox Urocyon cinereoargenteus Threatened
Assessment Criteria   Met criterion for Endangered, D1, but designated Threatened, D1, due to rescue effect.
Reason for Designation
This southern fox is apparently expanding northward, but very few mature, breeding individuals are known to live in Canada. These animals are restricted to two sub-populations; one in the Rainy River – Thunder Bay region, which has a strong rescue effect, but rescue effect for the other, Pelee Island, is uncertain. Sub-population threats include incidental trapping and roadkill. Animals have been recorded in Manitoba and Quebec, but breeding is not evident at this time. Recent records in New Brunswick likely represent dispersing non-breeding animals.
Range   ON
Status History
Designated Special Concern in April 1979. Status re-examined and designated Threatened in May 2002 and November 2015.
 
Peary Caribou Rangifer tarandus pearyi Threatened
Assessment Criteria   A2a
Reason for Designation
This subspecies of caribou is endemic to the Canadian Arctic Archipelago, living on the edge of plant growth in polar desert and arctic tundra environments. The current population is estimated at 13,200 mature individuals. From a population high of 22,000 in 1987, the species experienced a catastrophic die-off in the mid-1990s related to severe icing events in some parts of its range. The population was ca. 5,400 mature individuals in 1996, the lowest since surveys first commenced in 1961. Of four subpopulations, two are currently showing an increasing trend, one is stable, and the fourth had fewer than 10 individuals at the last count in 2005, with no evidence of any recovery. The overall population has experienced an estimated three-generation decline of 35%, but has been increasing over the past two decades. The highest-impact threats derive from a changing climate, including increased intensity and frequency of rain-on-snow events negatively affecting forage accessibility in winter, and decreased extent and thickness of sea ice causing shifts in migration and movement patterns.
Range   NT NU
Status History
The original designation considered a single unit that included Peary Caribou, Rangifer tarandus pearyi, and what is now known as the Dolphin and Union Caribou, Rangifer tarandus groenlandicus. It was assigned a status of Threatened in April 1979. Split to allow designation of three separate populations in 1991: Banks Island (Endangered), High Arctic (Endangered) and Low Arctic (Threatened) populations. In May 2004 all three population designations were de-activated, and the Peary Caribou was assessed separately from the Dolphin and Union Caribou, Rangifer tarandus groenlandicus. The subspecies pearyi is composed of a portion of the former "Low Arctic population", and all of the former "High Arctic" and "Banks Island" populations, and it was designated Endangered in May 2004. Status re-examined and designated Threatened in November 2015.
 

Birds

Louisiana Waterthrush Parkesia motacilla Threatened
Assessment Criteria   D1
Reason for Designation
During the breeding season in Canada, this songbird nests along clear, shaded, coldwater streams and forested wetlands in southern Ontario and southwestern Québec. It occupies a similar habitat niche in Latin America during the winter. The Canadian population is small, probably consisting of fewer than 500 adults, but breeding pairs are difficult to detect. Population trends for the Canadian population are uncertain. Declines have been noted in some parts of the Canadian range, particularly in its stronghold in southwestern Ontario, while new pairs have been found in others. Immigration of individuals from the northeastern U.S. is thought to be important to maintaining the Canadian population. However, while the U.S. source population currently appears to be fairly stable, it may be subject to future population declines due to emerging threats to habitat.
Range   ON QC
Status History
Designated Special Concern in April 1991. Status re-examined and confirmed in April 1996 and April 2006. Status re-examined and designated Threatened in November 2015.
 

Reptiles

Eastern Yellow-bellied Racer Coluber constrictor flaviventris Threatened
Assessment Criteria   C2a(i)
Reason for Designation
The Canadian distribution of this snake is restricted to three river valleys in southwestern Saskatchewan and one in extreme southeastern Alberta. Small population size (< 10,000), together with the use of communal dens for over-wintering, make the population particularly vulnerable to declines from stochastic events such as landslides during the denning period and from road mortality. Habitat loss and degradation in foraging habitat and along migration routes is also a concern.
Range   AB SK
Status History
Designated Special Concern in April 1991. Status re-examined and designated Threatened in November 2004 and November 2015.
 
Western Yellow-bellied Racer Coluber constrictor mormon Threatened
Assessment Criteria   A3cd+4cd
Reason for Designation
The Canadian distribution of this snake is confined to arid valleys of south-central British Columbia, an area with intensive agricultural development and an expanding human population and tourism industry. While relatively little is known of this elusive snake, it likely faces similar threats as other large snakes with which it shares its habitat (Western Rattlesnake, Great Basin Gophersnake). Migratory behaviour of snakes between overwintering dens on valley slopes and lowland foraging habitats, together with increasing numbers of roads and traffic volumes, make populations particularly sensitive to road mortality and habitat loss and fragmentation. Life history characteristics, such as small clutch size and infrequent reproduction by females, increase vulnerability of populations to disturbance, persecution, and changes in land use.
Range   BC
Status History
Designated Not at Risk in April 1991. Status re-examined and designated Special Concern in November 2004. Status re-examined and designated Threatened in November 2015.
 
Lake Erie Watersnake Nerodia sipedon insularum Special Concern
Assessment Criteria   not applicable
Reason for Designation
The Canadian distribution of this unique population of watersnakes is confined to four small islands in Lake Erie. In the United States, subpopulations have recovered because of an increased fish prey base, provided by introduced Round Goby. It is uncertain whether a similar recovery has occurred in Canadian subpopulations. There is concern that the largest subpopulation on Pelee Island continues to be threatened by road mortality, shoreline development, and persecution by humans.
Range   ON
Status History
Designated Endangered in April 1991 and in April 2006. Status re-examined and designated Special Concern in November 2015.
 

Fishes

Spotted Gar Lepisosteus oculatus Endangered
Assessment Criteria   B2ab(iii)
Reason for Designation
This species has a very limited distribution in Canada and populations are known from only three coastal wetlands of Lake Erie. Shallow vegetated habitats that are required for all life stages continue to be degraded and are at risk from invasive aquatic vegetation, removal of native vegetation, filling, dredging, and siltation.
Range   ON
Status History
Designated Special Concern in April 1983. Status re-examined and confirmed in April 1994. Status re-examined and designated Threatened in November 2000 and in May 2005. Status re-examined and designated Endangered in November 2015.
 
Little Quarry Lake Benthic Threespine Stickleback Gasterosteus aculeatus Threatened
Assessment Criteria   D2
Reason for Designation
This small, robust-bodied freshwater fish is a unique Canadian endemic that is restricted to one small lake in coastal British Columbia. The wildlife species is highly susceptible to extinction from aquatic invasive species that have been observed to cause rapid extinction of similar species in at least two other lakes. Many invasive aquatic species already occur in southwestern British Columbia, and any range expansion or introduction of new invasive species to Little Quarry Lake would likely lead to the extinction of this species.
Range   BC
Status History
Designated Threatened in November 2015.
 
Little Quarry Lake Limnetic Threespine Stickleback Gasterosteus aculeatus Threatened
Assessment Criteria   D2
Reason for Designation
This small, slender-bodied freshwater fish is a unique Canadian endemic that is restricted to one small lake in coastal British Columbia. The wildlife species is highly susceptible to extinction from aquatic invasive species that have been observed to cause rapid extinction of similar species in at least two other lakes. Many invasive aquatic species already occur in southwestern British Columbia, and any range expansion or introduction of new invasive species to Little Quarry Lake would likely lead to the extinction of this species.
Range   BC
Status History
Designated Threatened in November 2015.
 
River Redhorse Moxostoma carinatum Special Concern
Assessment Criteria   not applicable
Reason for Designation
This freshwater fish species occurs in rivers in densely populated regions of Ontario and Québec. Although collected at new locations in both Ontario and Québec, the species has likely been extirpated from several rivers within its range. It comes close to meeting Threatened criteria due to a small area of occupancy and relatively few locations. Its persistence is limited by barriers to movement, altered flow regimes, turbidity, eutrophication and habitat deterioration from agriculture and industrial activities. The species may become Threatened if these threats are neither reversed nor managed with demonstrable effectiveness.
Range   ON QC
Status History
Designated Special Concern in April 1983. Status re-examined and confirmed in April 1987, April 2006, and November 2015.
 

Arthropods

Hoptree Borer Prays atomocella Endangered
Assessment Criteria   B1ab(iii)+2ab(iii)
Reason for Designation
This species is dependent on its sole larval host plant, Common Hoptree, which is confined to a narrow swath of southwestern Ontario and currently assessed as Special Concern. This moth has an even more limited range than that of its host – it is known only from the western shore of Point Pelee, and from Pelee Island. Very few individuals have been detected. The most imminent threats include loss of shoreline habitat through erosion, vegetation succession, and invasive plant species.
Range   ON
Status History
Designated Endangered in November 2015.
 
Nuttall's Sheep Moth Hemileuca nuttallii Endangered
Assessment Criteria   B1ab(iii)c(iv)+2ab(iii)c(iv)
Reason for Designation
This large, showy and conspicuous moth is restricted to Antelope-brush habitat in the Okanagan Valley of British Columbia. That habitat type has declined considerably in quality and extent in the past century and remains under threat due to continued conversion to viticulture, residential and commercial development, and impact of wildfires. This is a rare moth in Canada: very few have been observed since the first record in 1920. Potentially large fluctuations in the population size may affect its long-term viability.
Range   BC
Status History
Designated Endangered in November 2015.
 
Lake Huron Grasshopper Trimerotropis huroniana Threatened
Assessment Criteria   B1ab(iii)+2ab(iii)
Reason for Designation
This globally rare grasshopper is endemic to the Great Lakes region of Ontario, Michigan, and Wisconsin where it is restricted to dunes along the shores of lakes Huron, Michigan, and Superior. In Canada, it is known from 11 dune sites: one location on the east shore of Lake Superior, and seven on Lake Huron at the south shore of Manitoulin Island and Great Duck Island. Formerly, it occurred at three additional sites on Lake Huron but these subpopulations appear to have become extirpated in the 1990s, likely as a result of residential and commercial development combined with intensive recreational use which damaged much of the dune habitat. While recreational use by pedestrians and off-road vehicles continue to threaten some dunes, other sites have undergone recent improvements under dune stewardship programs. Additional threats to dune environments include invasive plants and changes in lake levels related to climate change, natural cycles, or lake level management.
Range   ON
Status History
Designated Threatened in November 2015.
 

Molluscs

Rainbow Villosa iris Special Concern
Assessment Criteria   not applicable
Reason for Designation
This small mussel is widely distributed in southern Ontario. Surveys since the previous assessment in 2006 have found large numbers of individuals in previously unknown localities, especially at headwaters of larger rivers. There is strong evidence of recent recruitment in six of the seven subpopulations examined. Although it has been lost from Lake Erie and the Detroit and Niagara Rivers, it was apparently never common in these waters. Two subpopulations (Ausable River and Lake St. Clair) have low abundance and are showing signs of continued decline. Ongoing threats to some subpopulations include invasive species (dreissenid mussels and Round Goby) and pollution (household sewage and urban wastewater as well as agricultural effluents). The species may become Threatened if threats are not effectively managed or mitigated.
Range   ON
Status History
Designated Endangered in April 2006. Status re-examined and designated Special Concern in November 2015.
 

Vascular Plants

Colicroot Aletris farinosa Endangered
Assessment Criteria   A2ace+3ce+4ace
Reason for Designation
This perennial herb is restricted to remnant, disturbance-dependent prairie habitats in southwestern Ontario. It continues to decline in the face of multiple threats, including habitat modification, invasive species, and browsing by deer. Prairie habitat, for example, naturally transitions to less suitable habitat types in the absence of periodic disturbance (e.g., fire), and its quality and extent are also vulnerable to ongoing urban and industrial development. Recent construction of a new transportation corridor caused the removal of more than 50% of all mature plants in the Canadian population and loss of habitat. Although plants have been transplanted from the transportation corridor to nearby restoration sites, it is too early to know whether these relocated subpopulations will be self-sustaining so they cannot yet be considered to contribute to the population.
Range   ON
Status History
Designated Threatened in April 1988. Status re-examined and confirmed in November 2000. Status re-examined and designated Endangered in November 2015.
 
Bear's-foot Sanicle Sanicula arctopoides Threatened
Assessment Criteria   B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)
Reason for Designation
This perennial wildflower occurs in Canada only along a 30 km stretch of coastline in extreme southeast Vancouver Island. While this wildflower can live more than 10 years, it flowers and fruits once and then dies. It occupies small areas of remaining meadow habitat, which is being modified by invasion of exotic plants. Several new sites, discovered since the species was last assessed, have reduced the risk to this plant. Most of the Canadian population occurs at one site, which is also threatened by grazing by an expanding non-migratory, newly resident Canada Goose population. Severe trampling by humans also affects a few sites. Many of the known subpopulations have relatively few individuals and may not persist. 
Range   BC
Status History
Designated Endangered in May 2001. Status re-examined and designated Threatened in November 2015.
 
Common Hoptree Ptelea trifoliata Special Concern
Assessment Criteria   not applicable
Reason for Designation
In Canada, this small, short-lived tree occurs in southwestern Ontario, colonizing sandy shoreline habitats. A long-term decline in habitat quality and extent is predicted due to the effects of shoreline hardening, and historical sand mining in Lake Erie. One subpopulation depends on continuing management efforts. Improved survey effort has significantly increased the number of mature individuals, which reduces the overall risk to this species.
Range   ON
Status History
Designated Special Concern in April 1984. Status re-examined and designated Threatened in November 2002. Status re-examined and designated Special Concern in November 2015.
 
Giant Helleborine Epipactis gigantea Not at Risk
Assessment Criteria   not applicable
Reason for Designation
In Canada, the range of this orchid is restricted to a small region of southern British Columbia. It was previously assessed as Special Concern, but additional subpopulations have been found. Therefore the species is much more abundant than previously documented. Almost half of the known subpopulations occur in protected areas. It also appears to be much less threatened by orchid collectors than previously thought.
Range   BC
Status History
Designated Threatened in April 1984. Status re-examined and designated Special Concern in April 1998. Status re-examined and designated Not at Risk in November 2015.
 

Lichens

Flooded Jellyskin Leptogium rivulare Special Concern
Assessment Criteria   not applicable
Reason for Designation
Since this lichen was last assessed in 2004, increased search effort and a better understanding of its habitat requirements have revealed new occurrences in Manitoba, Ontario, and Québec and the minimum number of mature individuals is now estimated at 350,000. Canada is thus the stronghold for this species which has declined or disappeared from elsewhere in its global range. Emerald Ash Borer is a major threat killing ash trees that are an important host species for this lichen where it is most abundant in southern Ontario. Up to 50% of the population may be affected within the next few decades. Another threat is climate change which is expected to create drier conditions that will reduce seasonal flooding which this lichen requires to survive. It also needs calcareous enrichment, and as a result has an even more patchy distribution in the inaccessible boreal regions of Manitoba and Ontario where the number of individuals is lower but not accurately known. The predicted impact of these two threats on this lichen results in the recommended status of Special Concern.
Range   MB ON QC
Status History
Designated Threatened in May 2004. Status re-examined and designated Special Concern in November 2015.
 


02/09/2016