Consultation on Amending the List of Species under the Species at Risk Act: Terrestrial Species 2012: COSEWIC Summaries
The following section presents a brief summary of the reasons for the COSEWIC status designation of individual species, and their biology, threats, distribution and other information. For a more comprehensive explanation of the conservation status of an individual species, please refer to the COSEWIC status report for that species, also available on the SARA Public Registry
or contact:
COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment Canada
Ottawa ON K1A 0H3
The text information for each species is taken directly from the COSEWIC executive summaries.
- American Burying Beetle (Nicrophorus americanus)
- Baird’s Sparrow (Ammodramus bairdii)
- Behr’s Hairstreak (Satyrium behrii)
- Black-tailed Prairie Dog (Cynomys ludovicianus)
- Buffalograss (Bouteloua dactyloides)
- Buff-breasted Sandpiper (Tryngites subruficollis)
- Collared Pika (Ochotona collaris)
- Eastern Baccharis (Baccharis halimifolia)
- Goldencrest (Lophiola aurea)
- Grizzly Bear (Ursus arctos) Western population
- Hairy Prairie-clover (Dalea villosa)
- Hooded Warbler (Setophaga citrina)
- Magnum Mantleslug (Magnipelta mycophaga)
- Northern Dusky Salamander (Desmognathus fuscus) Carolinian population
- Okanagan Efferia (Efferia okanagana)
- Tiny Cryptantha (Cryptantha minima)
- Western Screech-Owl kennicottii subspecies (Megascops kennicottii kennicottii)
- Western Screech-Owl macfarlanei subspecies (Megascops kennicottii macfarlanei)
- Yellow-breasted Chat virens subspecies (Icteria virens virens)
- Yukon Draba (Draba yukonensis)
- Ammodramus bairdii
- Baccharis halimifolia
- Bouteloua dactyloides
- Cryptantha minima
- Cynomys ludovicianus
- Dalea villosa
- Desmognathus fuscus
- Draba yukonensis
- Efferia okanagana
- Icteria virens virens
- Lophiola aurea
- Magnipelta mycophaga
- Megascops kennicottii kennicottii
- Megascops kennicottii macfarlanei
- Nicrophorus americanus
- Ochotona collaris
- Satyrium behrii
- Setophaga citrina
- Tryngites subruficollis
- Ursus arctos
Alberta
British Columbia
- Behr’s Hairstreak
- Buff-breasted Sandpiper
- Collared Pika
- Grizzly Bear (Western population)
- Magnum Mantleslug
- Okanagan Efferia
- Western Screech-Owl kennicottii subspecies
- Western Screech-Owl macfarlanei supspecies
Manitoba
- Baird’s Sparrow
- Buffalograss
- Buff-breasted Sandpiper
- Grizzly Bear (Western population)
- Hairy Prairie-clover
New Brunswick
- none
Newfoundland and Labrador
- none
Northwest Territories
Nova Scotia
Nunavut
Ontario
- American Burying Beetle
- Buff-breasted Sandpiper
- Hooded Warbler
- Northern Dusky Salamander (Carolinian population)
- Yellow-breasted Chat virens subspecies
Prince Edward Island
- none
Quebec
Saskatchewan
- Baird’s Sparrow
- Black-tailed Prairie Dog
- Buffalograss
- Buff-breasted Sandpiper
- Grizzly Bear (Western population)
- Hairy Prairie-clover
- Tiny Cryptantha
Yukon
Scientific name
Nicrophorus americanus
Taxon
Arthropods
COSEWIC status
Extirpated
Canadian range
Ontario, Quebec
Reason for designation
There is sufficient information to document that no individuals of the wildlife species remain alive in Canada. This includes that it: (1) is a large distinctive and conspicuous insect not seen for 39 generations; (2) has not been seen despite a tenfold increase in the number of field entomologists and an estimated 300,000 general trap nights of which at least some should have resulted in capture of this species, as well as studies of carrion-feeding beetles that did not reveal it; (3) comes to lights yet still not seen in thousands of light traps; and (4) a recent directed search in the general area where last seen 60 and 39 years ago that failed to find this species.
Species information
The American Burying Beetle is a carrion-feeding beetle of the family Silphidae. The species is distinct and there are no proposed subspecies or species forms. It is one of the most striking beetle species in Canada due to its large size and the brilliant orange markings on its otherwise black body.
Distribution
Former and current North American distribution of the American Burying Beetle.
Source: November 2011 COSEWIC Status Report.
It appears very unlikely that the American Burying Beetle has been present but undocumented anywhere within its range in the last quarter century. Natural re-colonizing by the species of its former range in Canada appears to be very unlikely. The species might be reintroduced from United States populations through captive breeding programs.
Habitat
The species requires well-drained humic or loamy soils without impediments to digging in order to quickly excavate the brood chamber in which to lay its eggs. In eastern North America, soils of this type occur principally in primary, undisturbed deciduous forest. Toward the west side of its range these soils are available in grassland ecotypes as well. There is, as yet, no consensus on whether the species is obligate on particular habitat types.
Biology
The species has one generation over the period of a year, with individuals existing from the summer to their death in the following year. Individuals will typically have the opportunity to reproduce only once. Following emergence from the ground, in the late summer or early fall of the year in which it was laid, the teneral begins feeding and possibly searching for reproductive opportunities. In the fall of their first year they burrow into the ground to overwinter. The adults again emerge in the spring to feed and begin their evening search for a recently deceased suitable brood carcass.
Sexton beetles (genus Nicrophorus) show biparental care to a unique degree for beetles. Reproduction is completely dependent upon the availability of a carcass which can be entombed in a manner suitable for feeding larvae. Vertebrate carcasses of any sort are used; however, bird chicks and rodents are probably most often employed. American Burying Beetle tends to use larger carcasses than its smaller congeners. When a suitable carcass is located the individual or pair will compete with other carrion-eating insects for possession of the carcass until a single pair remains. The carcass then may be moved as far as a metre until soil suitable for excavation is reached, then buried before the dawn.
The species is not migratory, and its movements are limited. However, it does range more widely than its smaller congeners (i.e., species of the same genus), and likely across more habitat types. Adults begin their seasonal activities when the temperature exceeds 15°C. They are crepuscular and nocturnal, and generally active from April through September.
Population sizes and trends
It is believed that the species has been extirpated in Canada and from all states coterminous with Canada. It is estimated that there are fewer than 1 000 individuals in the currently disjunct Block Island, Rhode Island, population, and the two western United States populations each contain an unknown, though certainly much larger, number of individuals.
Limiting factors and threats
There is ongoing discussion regarding the cause of the decline in the range and abundance of the American Burying Beetle. There are a number of hypotheses, many of which are unconvincing due to the apparent lack of impact on congeners of similar behaviour and requirements. It seems unlikely that any one factor is responsible for the species’ decline.
Direct impacts are thought to have been: the use of artificial lighting, which may affect the species’ behaviour, roadkill of wandering adults, and mortality due to the use of insecticides. Species-specific diseases have been considered, but there is no evidence to support this mechanism as likely.
Direct predation seems likely to have played a part, given the increase in appropriate predators over the species’ range, but is not thought to be the major cause of the decline either of the species or its supply of brood carcasses. The increase in predacious, free-ranging domestic dogs and cats, which likely disturb carcasses, may be a factor.
Reduction of brood carcass resources may be a major factor. This reduction is thought to have come about due to the decreased populations of species of appropriate size for brood carcasses, and increased competition with scavenging animals and the more abundant congeners. Reduction in the use of waste meat dumps and cessation of using whole fish as fertilizer will also have reduced carrion resources available to the beetles.
Habitat alteration and fragmentation is generally considered to be the primary cause for decline. Fragmentation increases the need for species’ movement across unsuitable habitats and over roads. The development of dense understory in cleared forest areas increases the difficulty of burying the brood carcass, and hence the vulnerability of the beetle pair to predation.
Special significance of the species
The species offers a rich resource for behavioural study, particularly as it is a member of one of the few insect groups that exhibit parental behaviour. Having been recognized as having suffered an extraordinary and presumably anthropogenic decline, the species offers the potential for enlightenment regarding human impacts on invertebrate species, and other ecological subjects. As a representative of the invertebrate megafauna, with intriguing behaviour, the species has great potential for bringing the plight of lesser-known organisms to the public eye.
Existing protection or other status designations
Globally, the American Burying Beetle is listed in the IUCN Red List as Critically Endangered, based on a population reduction of ≥90% and a decline in area of occupancy and occurrence. The species was listed as an Endangered Species federally in the United States through the U.S. Endangered Species Act in August 1989, based on the drastic decline and extirpation of the species over nearly its entire historical range. NatureServe lists the species as globally imperiled. The species has not yet been assessed under the National General Status protocols for Canada.
Scientific name
Ammodramus bairdii
Taxon
Birds
COSEWIC status
Special Concern
Canadian range
Alberta, Saskatchewan, Manitoba
Reason for designation
Canada supports about 60% of the breeding population of this prairie songbird. The species was common and perhaps even abundant historically. It suffered declines stemming from agricultural conversion of its native prairie habitat across the Great Plains. There is good evidence for population declines in recent decades, but the species is difficult to monitor effectively, and information on short-term population trends is relatively weak. Loss and degradation of its specialized grassland habitat, on both its breeding and wintering grounds, are believed to pose the most significant threats. Evidence of long-term population declines, coupled with ongoing threats to habitat, are the primary reasons for elevating the status of this species from Not at Risk to Special Concern.
Wildlife species description and significance
The Baird’s Sparrow is a secretive grassland sparrow, distinguished from other sparrows by “moustache” marks on its yellowish-ochre face, a necklace of thin streaks across its breast, and a song that usually ends in a wiry, musical trill. As a range-restricted species of the northern prairies, it is a valuable grassland indicator for that region.
Distribution
The Baird’s Sparrow breeds from southern Alberta, Saskatchewan and southwest Manitoba, south to Montana, Wyoming, and South Dakota. Canada encompasses about 45% of its breeding range, and is home to an even greater proportion of the global population. Baird’s Sparrows winter from southern Arizona, New Mexico, and Texas south to north central Mexico.
Breeding and wintering distribution of Baird's Sparrow.
Source: “Birds of North America Online” maintained by the Cornell Lab of Ornithology, Ithaca, NY.
Habitat
This species mainly breeds in large patches of mixed grass and fescue prairie with sparse shrubs, moderate grass heights, and some litter. These features can sometimes be met by non-native habitats, but breeding success can be poor in some of these habitats, such as tame hay and croplands. Over 75% of native grassland in the Baird’s Sparrow’s breeding range has been destroyed since the 1800s, mostly converted to cropland. Habitat destruction, degradation, and fragmentation continue across the species’ range.
Biology
Baird’s Sparrows likely breed in their first year and live about 3 years. They nest in late May through July, raising an average of 1.5 young during each of the one or two breeding attempts they have each year. About half of nests fail, with most lost to a variety of avian and mammalian predators. Birds rarely return to the same place to breed each year, but instead settle wherever conditions are suitable for breeding.
Population sizes and trends
The global population is estimated from Breeding Bird Survey (BBS) data as 1.2 million individuals (± 50%), of which 60% breed in Canada. The BBS shows a statistically non-significant annual average rate of decline of 2.0% in the population in Canada since 1970 (95% CI: -4.5 to 0.6). However, because Baird’s Sparrows appear to shift their breeding distributions in response to patterns of precipitation, using combined long-term BBS data for Canada and the U.S. is believed to represent a more appropriate source of population trend estimates. This yields a statistically significant decline of 25% (95% CI: -13 to -39) over the past decade.
Threats and limiting factors
The main threats to Baird’s Sparrows are habitat destruction, degradation, and fragmentation, caused by a variety of factors, with energy extraction becoming particularly important recently. Other threats include disruption of natural processes (grazing, fire, and drought), agricultural operations, brood parasitism by cowbirds, pesticides, and climate change.
Protection, status, and ranks
The Baird’s Sparrow is protected under the Canada–U.S. Migratory Birds Convention Act and Manitoba’s Endangered Species Act. It is recognized as being at risk on several non-legal status rankings across its range, including the U.S. Birds of Conservation Concern and the Partners in Flight and Audubon Society Watch Lists. Various programs are in place to conserve native grassland, but less than 25% of the Canadian prairie region is still native grassland, and only 15% of native grassland across this species’ range is protected.
Scientific name
Satyrium behrii
Taxon
Arthropods
COSEWIC status
Endangered
Canadian range
British Columbia
Reason for designation
This small butterfly is restricted to Antelope-brush habitat in British Columbia, a habitat that has decreased considerably in extent in the past century and remains under threat due to land use change (conversion to viticulture, residential and commercial development) and the impact of fire. It rarely disperses much more than 120 m and persists in small, isolated fragments of habitat, which continue to decline in area and quality. Large annual fluctuations in population size, as documented for the largest Canadian population, increase the species’ vulnerability and call into question its long-term viability.
Wildlife species description and significance
Behr’s Hairstreak (Satyrium behrii) is a small butterfly (wingspan 2.5–2.9 cm) in the family Lycaenidae. The dorsal forewing and hindwing surfaces have wide black margins that surround a rich, yellowish-orange-brown patch. There is one subspecies of Behr’s Hairstreak in Canada.
The larval host plant of Behr’s Hairstreak is Antelope-brush, which has special significance in Canada as a symbol used by conservation organizations for the protection of associated plant communities and grasslands within the Okanagan region. First Nations peoples within the region hold butterflies (in general) and the Antelope-brush plant significant in their cultures. Antelope-brush is also significant to the wild game management and livestock grazing industry sectors.
Distribution
The Canadian range of Behr’s Hairstreak is restricted to south-central British Columbia from Penticton in the north to Osoyoos in the south. The butterfly inhabits the low elevation (280–760 m above sea level) Antelope-brush plant communities on both the east and west side of the south Okanagan Valley. The species occupies an area of less than 12 km².
Canadian distribution of Behr's Hairstreak.
Source: May 2012 COSEWIC Status Report with permission of Orville Dyer.
Habitat
Behr’s Hairstreak is primarily recorded from the Antelope-brush/Needle-and-thread Grass plant community. Important habitat attributes include plant communities with Antelope-brush plants greater than 30 years old; sparse tree cover (particularly Ponderosa Pine, which may be required by adults for shelter during inclement weather, daytime temperature extremes, and nighttime resting); and the presence of puddling sites (mud puddles where adult butterflies obtain moisture and salt).
Behr’s Hairstreak habitat: Antelope-brush.
Biology
Behr’s Hairstreak has one generation per year; the flight period is from mid-May through late July and peaks in mid-June. Eggs are laid singly on the leaves and branches of Antelope-brush where they overwinter. The eggs hatch in early spring, and the larvae develop from late March to late May and pupate in late spring. The pupae are attached to stems of Antelope-brush and this stage lasts approximately two weeks. Behr’s Hairstreak is not known to migrate. Adults appear to have limited dispersal capabilities and remain within close proximity to Antelope-brush habitat. Average dispersal distances for the butterfly, based on field studies completed in the south Okanagan Valley, are 80–120 m depending on spring weather, with a maximum-recorded dispersal of 1.2 km.
Population sizes and trends
Analyses suggest that even the largest known population is unlikely to be sustainable in the long term and extant populations are fragmented, separated by areas of unsuitable habitat that are mostly beyond the species’ dispersal capacities.
Habitat trend information shows Antelope-brush plant communities have declined significantly in quantity and quality in the past 200 years. The most recent mapping (2009) shows 3 217 ha of Antelope-brush/Needle-and-thread Grass plant community remaining in the south Okanagan, which is approximately one third of its historic distribution (as of 1800).
Threats and limiting factors
Behr’s Hairstreak faces many threats, most of them associated with habitat conversion and associated fragmentation. The main limiting factor for Behr’s Hairstreak is the availability of high quality and older age-class Antelope-brush host plants. Adult butterflies are also limited by nectar plant availability due to short proboscis (tongue) length, which cannot reach the nectar in flowers of plant species that have a deep corolla.
Protection, status, and ranks
Behr’s Hairstreak is protected under the federal Species at Risk Act, Canada Wildlife Act, British Columbia Park Act, and Ecological Reserves Act. The butterfly is recommended for listing as Identified Wildlife under the British Columbia Forest and Range Practices Act, Wildlife Act, and Wildlife Amendment Act.
Behr’s Hairstreak (columbia subspecies) has a global heritage rank of G5T4T5 (secure), national rank of N1N2 (critically imperiled/imperiled), provincial rank of S1 (imperiled) and is a priority under the British Columbia Conservation Framework. Conservation lands (private and public) protect 15% of existing Antelope-brush habitat in B.C.
Scientific name
Cynomys ludovicianus
Taxon
Mammals
COSEWIC status
Threatened
Canadian range
Saskatchewan
Reason for designation
This small mammal is restricted to a relatively small population in southern Saskatchewan. The change in status from Special Concern to Threatened is based mainly on the threat of increased drought and sylvatic plague, both of which would be expected to cause significant population declines if they occur frequently. Drought events are predicted to increase in frequency due to a changing climate. Sylvatic plague was first recorded in 2010. Although the Canadian population is in a protected area, it exists within a small area and is isolated from other populations, all of which are located in the United States.
Wildlife species description and significance
The Black-tailed Prairie Dog is a diurnal, burrow-dwelling squirrel that lives in colonies. Individuals are 35–42 cm in body length, have short legs, tails with a black tip, small ears and brown to reddish-brown fur with an off-white underbelly.
Prairie dogs are an important component of native short- and mixed-grass prairie ecosystems and provide breeding habitat for two endangered species, the Mountain Plover and Burrowing Owl, as well as being an important prey for several rare and endangered species such as the reintroduced Black-footed Ferret. The Canadian population of the Black-tailed Prairie Dog is considered a distinct local population because it is at the northernmost point of the species’ range and is isolated from populations in the United States.
Distribution
The Black-tailed Prairie Dog occurs in the short- and mixed-grass prairies of North America from northern Mexico to Saskatchewan, Canada. The species is extirpated from east Texas north to eastern North Dakota, and where it remains the actual area occupied is small and colonies are mainly small and isolated. In Canada, the population is located in the lower Frenchman River valley and adjacent areas in southwestern Saskatchewan. The Canadian population exists as 18 colonies in close proximity (12 km²); interchange between colonies is likely and the population is considered a single designatable unit. A second population, near Edmonton, Alberta, derived from escaped captives, is not discussed, as per COSEWIC guidelines.
Canadian distribution of Black-tailed Prairie Dog.
Source: Tuckwell, J. and T. Everest. 2009. Management Plan for the Black-tailed Prairie Dog (Cynomys ludovicianus) in Canada. Species at Risk Act Management Plan Series. Parks Canada Agency, Ottawa. vi + 31 pp.
Habitat
The Black-tailed Prairie Dog lives in grasslands with soils that support extensive burrow systems. The spatial extent of prairie dog colonies tends to be stable in the absence of sylvatic plague outbreaks, and can occupy the same area for many years. Colonies are characterized by short vegetation and numerous mounds of soil (often 30–60 cm high) heaped around each burrow entrance.
Biology
Black-tailed Prairie Dogs are herbivorous, predominantly eating grasses. They live in family groups (coteries) composed of one male and 2–4 females, often with 1–2 yearlings also present. Coteries are aggregated into colonies. Animals older than 2 years mate in March–April, with 2–6 young born in May. Maximum recorded age is 5 yr (males) and 8 yr (females). Most dispersal is by yearling males. Canadian Black-tailed Prairie Dogs hibernate for 4 months over winter.
Population sizes and trends
The size of the Canadian Black-tailed Prairie Dog population is not known. However, the minimum population size in 2010 is estimated at 6,165–9,360 mature individuals, using visual count data and the total area occupied by colonies.
Colony boundaries have been mapped periodically since 1970, and biennially since 1992. Colonies range in size from 0.6–172 ha, and total area occupied by Black-tailed Prairie Dogs in Canada has increased from a low of 828.8 ha (8 km²) in 1992–93 to a high of 1 235.4 ha (12 km²) in 2009. However, because colony area is not a good measure of prairie dog density, an increase in colony extent may not indicate an increase in population size.
It is difficult to estimate either a population estimate or trend because prairie dog density can vary greatly among colonies and between years. Visual counts have been conducted at several colonies in Grasslands National Park since 1992 and indicate that Black-tailed Prairie Dog populations undergo large (i.e. 4x average) short-term fluctuations in population size. Variations in growing conditions and/or interactions with other factors, including drought, presumably contribute to these substantial fluctuations. Different indicators suggest a decline has occurred in the last 10 years or, alternatively, that any decline is not statistically significant. Also, the population data include juveniles and COSEWIC assessments are based only on adults. Overall, the population size and trend is unknown but may be stable because decreases in density within colonies appear to be offset by stable or increasing size of the total population area.
Threats and limiting factors
The Canadian population exists as a single location because two threats, epizootic sylvatic plague and drought may impact the entire population in a short period. In 2010, a single Black-tailed Prairie Dog in Canada was found dead from sylvatic plague and plague was suspected in the loss of a small (4 ha) colony more than 10 km away. In 2011, pups were recorded where the plague had been found, suggesting the plague was not an epizootic event because numerous neighbouring colonies were not extirpated. Drought limits food production and likely explains fluctuating population levels. Drought is a natural event but frequency of drought is predicted to increase.
The recent (2009) reintroduction of Black-footed Ferrets has exposed prairie dogs to a predator they have not experienced in 70 years, and the resilience of the Canadian population to both sylvatic plague and ferret predation is unclear. The impact of Black-footed Ferrets on Black-tailed Prairie Dogs is being monitored but no results were available during the writing of this report.
Most other threats are minor, mainly because activities within the protected regulation zone containing the colonies are restricted. An expansion of the population beyond the current zone would be required for the species to recover to the point of not being listed by COSEWIC, but numerous threats outside the zone suggest expansion is unlikely.
Protection, status, and ranks
The Black-tailed Prairie Dog was previously assessed by COSEWIC in November 2000 and is currently listed as Special Concern on Schedule 1 of the federal Species at Risk Act (SARA). A management plan was completed in 2009. Fifty-nine percent of colony area occurs within Grasslands National Park and is protected under the Canada National Parks Act. In Saskatchewan, the Black-tailed Prairie Dog is protected under the Saskatchewan Wildlife Act, which protects them from being killed, harmed, or harassed without a permit. The Saskatchewan Wildlife Habitat Protection Act protects their habitat on Crown land. Black-tailed Prairie Dog colonies are protected within the 2007 regulation zone boundary as critical habitat for the Black-footed Ferret and Burrowing Owl. Permits to control Black-tailed Prairie Dogs may be issued by the Saskatchewan Ministry of Environment to control Black-tailed Prairie Dogs, if their colonies expand beyond their 2007 boundary. To date, one permit has been issued annually.
Male specimen
Scientific name
Bouteloua dactyloides
Taxon
Vascular plants
COSEWIC status
Special Concern
Canadian range
Saskatchewan, Manitoba
Reason for designation
This grass occurs in limited areas of remnant short-grass prairie in southern Saskatchewan and Manitoba. Threats to this species include coal strip mining, invasive alien plants and overgrowth by woody vegetation and high grass that were once controlled by bison grazing and fire. However, recent survey efforts have increased the known number of populations and it no longer qualifies as a threatened species.
Wildlife species description and significance
Buffalograss is a low-growing, stoloniferous (bearing runners), curly-leaved, perennial grass forming dense, clonal mats. The species is primarily dioecious: male (staminate) and female (pistillate) flowers are found on different plants. Male plants have slender, erect stems, mostly 6–12 cm high, bearing 1–3, 1-sided spikes that are about 1 cm long. The pistillate plants have short, often prostrate stems beneath the leaves, and bear flower clusters that remain together to form hard, globular “burs” that become the seed dispersal units. Buffalograss is an important drought-tolerant forage and turf grass in the United States.
Distribution
Buffalograss is widespread in North America, ranging northward from Central Mexico, over the Chihuahuan and Great Plains grasslands of the United States, just reaching into the southernmost Canadian prairie provinces. In Canada, it is a peripheral species found in southeastern Saskatchewan and southwestern Manitoba. Less than 1% of the global population is in Canada.
Habitat
In Canada, Buffalograss occurs on remnant patches of shortgrass prairie, in clay to clay-loam soils, often below shale outcrops, on dry, shallow valley bottoms and lower slopes, or on south- or west-facing mid-slope benches of the Souris and Blind river valleys. The species requires an environment with little competition from taller, more competitive grasses and herbs. Grazing and moderate trampling may help maintain suitable habitat.
Biology
Buffalograss reproduces both vegetatively, forming solid clonal mats, and sexually reproducing by seeds produced from outcrossing via wind-pollination. In Canada, Buffalograss flowers in midsummer and produces seeds from late July to August. The seed-containing burs are dispersed by herbivores and water. The life expectancy at one year is approximately 2.16 years with a maximum life span of 35 years. The seeds have relatively long viability estimated between 25–35 years.
Canadian distribution of Buffalograss.
Source: Environment Canada. 2007. Recovery Strategy for the Buffalograss (Bouteloua dactyloides) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. vi + 30 pp.
Population sizes and trends
There are two populations of Buffalograss in Canada. The population in Manitoba is south of Melita along the Blind and Souris river valleys. The population in Saskatchewan is west of Estevan along both sides of the Souris River Valley. The number of mature individuals is unknown and difficult to estimate as Buffalograss occurs in clonal patches that are too interconnected to be distinguished from each other. However, due to detailed surveys and mapping since the species was last assessed in 2001, the size of the populations in Canada is much larger than originally estimated. This discrepancy is likely not due to growth of the populations but rather insufficient initial surveying.
Threats and limiting factors
The potential threats to Buffalograss arise, not so much from low numbers of plants present, but from its occurrence over a small area of unusual habitat, together with the possibility of altered land-use in the future. Potential threats to the Buffalograss populations in Canada in order of importance include: coal strip mining, invasive alien species, disruption of natural disturbance regimes including grazing and/or fire, flooding by reservoirs and dams, cultivation, and road construction or upgrades.
Protection, status, and ranks
Buffalograss is listed as Threatened under the federal Species at Risk Act. In Manitoba, Buffalograss is considered Threatened and is protected under the Endangered Species Act. Buffalograss is not protected in Saskatchewan, except one small population in the Buffalograss Ecological Reserve. The Canadian national NatureServe rank is N1 (critically imperilled), and in Manitoba and Saskatchewan it is S1 (critically imperilled).
Scientific name
Tryngites subruficollis
Taxon
Birds
COSEWIC status
Special Concern
Canadian range
Yukon, Northwest Territories, Nunavut, British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec
Reason for designation
The Canadian Arctic supports about 87% of the North American breeding range of this shorebird, and about 75% of its global population. The species was once common and perhaps even abundant historically, but it suffered severe declines stemming from intensive market hunting in the late 1800s and early 1900s. By the 1920s, it was thought to be at the brink of extinction. Its population has grown since hunting was banned in North America, but numbers remain much lower than those before hunting began. There is evidence for population decline in recent decades, and many conservation organizations consider the species to be of concern throughout its range. However, this species is difficult to monitor effectively, and data necessary to estimate population trends are currently lacking. Outside the breeding period, loss and degradation of its specialized grassland habitat, both on its wintering grounds in South America and along its migration routes, are believed to pose the most significant threats.
Wildlife species description and significance
The Buff-breasted Sandpiper (Tryngites subruficollis) is a medium-sized shorebird with a buff-coloured face and underparts, and brown to black speckling on its wings and back. It is the only North American shorebird with a lek mating system, in which males congregate to display to females during courtship.
Distribution
The Buff-breasted Sandpiper breeds in the Arctic regions of eastern Russia, Alaska, Yukon and northcentral Canada. It winters in South America, mainly in Argentina, Brazil and Uruguay. About 87% of the species’ North American range occurs in Canada, where it breeds along the mainland north coast of Yukon, Northwest Territories and Nunavut, and within the Canadian Arctic Archipelago. Adults migrate south to the wintering grounds through the North American interior, while juveniles tend to spread out to the Atlantic and Pacific coasts before heading south. Migration north to the breeding grounds is concentrated through the central parts of the United States and Canada, with a large proportion of the population passing through Alberta and Saskatchewan.
Breeding range of the Buff-breasted Sandpiper in North America.
Source: Modified from the May 2012 COSEWIC Status Report (map produced by Jennie Rausch, Environment Canada).
Habitat
The breeding grounds are exclusively within tundra habitats. On migration and during the winter, Buff-breasted Sandpipers occur primarily in grassland habitats. Prior to European settlement in North America, stop-over habitat for migrants was primarily native short-grass prairie that was grazed by bison. Most such habitat has since been cultivated. Nowadays, the birds primarily use a variety of human-altered sites for stopovers, such as crop fields, golf courses, airport runways, sod farms, and pastures grazed by domestic livestock. Buff-breasted Sandpipers winter mainly in the South American Pampas, where livestock grazing maintains their preferred short-grass habitat structure. Wintering populations also are commonly found next to coastal lagoons.
Biology
Males and females arrive simultaneously on the Arctic breeding grounds from late May through mid-June. Males perform courtship displays on territories to attract females. Females lay a single clutch of four eggs in a nest on the ground. Most birds depart for the wintering grounds by early September. The diet of Buff-breasted Sandpipers includes terrestrial insects and spiders, aquatic invertebrates and plant seeds.
Population sizes and trends
The most recent global estimate of Buff-breasted Sandpipers is 56,000 birds (range: 35 000–78 000). About 42 000 likely breed in Canada (range: 26 250–58 500), which accounts for about 75% of the species’ global population. The population is believed to have once numbered in the hundreds of thousands to millions prior to precipitous declines stemming from commercial hunting in the late 1800s and early 1900s. Recent observations suggest that the species has continued to decline over the past few decades, but no long-term monitoring data exist to verify this apparent trend.
Threats and limiting factors
Habitat loss, fragmentation and degradation are likely the primary threats to Buff-breasted Sandpiper populations. In the Arctic, breeding habitat overlaps areas of mineral, coal, oil and gas development.
Throughout much of the rest of the migration and winter range, native grasslands have largely disappeared, and the species has switched to using human-altered habitats. The Buff-breasted Sandpiper’s regular use of croplands may expose the birds to agrochemicals, while changing agricultural practices (e.g., altered grazing regimes, switch to no-till farming) may decrease food availability and limit suitable habitat. In addition, the development of wind energy projects along the North American migratory route could have negative consequences for the species.
Climate change may impact Buff-breasted Sandpipers in several ways. Northward advancement of shrub cover will dramatically alter its tundra breeding habitat. Rising sea levels and increased rainfall could flood the birds’ coastal habitat on both breeding and wintering grounds. More frequent and intense storms could increase mortality of juveniles migrating along the Atlantic coast. Climate change is also expected to cause more frequent and severe droughts in the Canadian Prairies and the U.S. Great Plains, which may negatively impact wetland and seasonal pond habitat and lead to decreased food availability during migration.
Protection, status, and ranks
The Buff-breasted Sandpiper is protected in Canada under the federal Migratory Birds Convention Act. It is considered near threatened on the IUCN Red List and of high conservation concern by both the U.S. Fish and Wildlife Service and the Canadian Shorebird Conservation Plan. The U.S. Shorebird Conservation Plan designates the Buff-breasted Sandpiper as highly-imperiled. In Canada, the Buff-breasted Sandpiper is ranked nationally as sensitive to extinction or local loss of populations. On the wintering grounds, it is classified as threatened in Argentina, vulnerable in part of Brazil, near threatened in Paraguay, and a priority species for conservation in Uruguay. None of the existing protections extend to conservation of the species’ habitat.
Scientific name
Ochotona collaris
Taxon
Mammals
COSEWIC status
Special Concern
Canadian range
British Columbia, Yukon, Northwest Territories
Reason for designation
This small rabbit-relative is a Beringian relict that is restricted to talus slopes in alpine areas in northern west British Columbia, Yukon, and Northwest Territories. This region comprises over half the global range of this species, and is witnessing climate-driven shifts in habitat, temperature, and precipitation at faster rates than elsewhere in Canada. A demonstrated sensitivity to climate variability, coupled with poor dispersal ability and the naturally fragmented nature of its populations, heightens the vulnerability of this small mammal to climate change. The species is well-studied in a very limited portion of its range, but baseline information on population trends at the range level, and a clear understanding of the extent and severity of climate impacts to this species and its habitat in the coming decades is limited. However, the best available information suggests that this species may be particularly sensitive to a changing climate, including concomitant increases in precipitation variability, leading to reductions in habitat availability. The potential of negative impacts of climate change to the persistence of this species over the long term is substantial.
Wildlife species description and significance
The Collared Pika (Ochotona collaris) is a small (~160 g), asocial, alpine-dwelling lagomorph. It is one of two pika species in North America, along with American Pika (O. princeps). Collared Pikas are dull grey with pale grey patches on their napes and shoulders, which form a partial collar around the neck. They display no obvious sexual dimorphism. Pikas have been deemed ‘harbingers of climate change’ because of their demonstrated sensitivity to climate patterns.
Distribution
In Canada, the Collared Pika occurs primarily in the mountainous regions of Yukon Territory, extending into northern British Columbia and into Northwest Territories west of the Mackenzie River. Outside Canada, Collared Pikas occur in southern and central Alaska. There is one designatable unit for Collared Pika in Canada.
The global range of Collared Pika (i.e., estimated extent of occurrence) and locations of specimen collections and field observations from Canada (Yukon and British Columbia).
Source: November 2011 COSEWIC Status Report.
Habitat
Collared Pikas inhabit primarily alpine boulder fields (talus) that are interspersed with meadow. This talus-meadow combination offers access to forage (meadow) and shelter from predators and weather (talus). Collared Pikas are behaviorally restricted to talus patches and typically remain within 10 metres of the talus edge when foraging in meadows. Population densities are generally higher on south-facing slopes presumably because of their higher primary productivity.
Biology
Collared Pikas are generalist herbivores that collect two diets during summer. The first is consumed immediately, while the second is stored in ‘haypiles’ within the talus matrix for consumption during winter. Pikas defend individual territories (about 15–25 m radius) and have a promiscuous mating system. Pikas become sexually mature after their first winter and, after a 30-day gestation, produce a litter of 3–4 offspring in a nest located within the talus. Most litters are produced in mid-June. Juveniles emerge to the surface 30 days later and disperse within days. Juveniles grow to near-adult size during their first summer and must establish a territory and a haypile before winter. Adults exhibit high site fidelity once a territory is established.
Annual survival has been linked to both winter climate and the timing of spring haypile initiation. The primary predator of Collared Pikas is the Short-tailed Weasel, and occasionally Red Foxes and raptors. Pikas generally do not live longer than 4 years and generation time is just over 2 years.
Population sizes and trends
A study of Collared Pika populations in a single location in the Ruby Ranges Ecoregion of southwestern Yukon showed that the population size fluctuated considerably over time. Although there are no other empirical data available on population sizes and trends elsewhere and almost no directed surveys, Collared Pikas are believed to be otherwise widespread and may be locally abundant within the species’ range.
Threats and limiting factors
Due to the remote nature of its range in Canada, direct disturbance to Collared Pika habitat and populations has been minimal and is expected to remain so in the coming decades. The greatest threat to Collared Pika populations is most likely to be from climate warming, the effects of which are already known to be occurring in this northern region that is characterized by a dry, subarctic climate. Local extirpations and upslope range retraction of American Pika has been documented in the interior Great Basin of the U.S., but the extent to which this condition is applicable to Collared Pika is unknown, given some differences in habitat and other uncertainties. The most likely risks to Collared Pika persistence are related to the direct effects of temperature, moisture or weather conditions and habitat changes. Pikas survive best under cool, dry conditions, and changes in either direction (i.e., higher temperatures, or cold wet conditions) leave them susceptible to death through exposure. Loss of suitable alpine habitat may occur through a) changes in the species composition of alpine vegetation communities, b) a direct loss of habitat due to treeline advance, or c) climate becoming physiologically intolerable. A loss of alpine habitat would increase distances between suitable patches, possibly reducing gene flow, rescue effects, and regional persistence.
Protection, status, and ranks
Currently, the Collared Pika is not listed under the Canadian Species at Risk Act, the United States Endangered Species Act or under the Convention on International Trade in Endangered Species of Wild Fauna and Flora. The International Union for the Conservation of Nature lists the Collared Pika as “Lower Risk/Least Concern.” The NatureServe conservation status ranks are Globally Secure, Nationally Secure in both Canada and the United States, and Secure in Alaska. Under the national General Status program, they are listed as Sensitive in Northwest Territories. The draft conservation status ranks for both Yukon and British Columbia were uplisted from Secure to Sensitive between the 2005 and 2010 assessments, and they are listed nationally as Sensitive.
Scientific name
Baccharis halimifolia
Taxon
Vascular plants
COSEWIC status
Threatened
Canadian range
Nova Scotia
Reason for designation
The species is an Atlantic Coastal Plain Flora species. A rare Canadian disjunct shrub restricted to very specific salt marsh habitat in southern Nova Scotia. Its coastal habitat is declining due to increasing shoreline development. Further climate change effects, including rising sea level and increasing and more frequent storm surges, will cause habitat loss and degradation as well as impact individuals over the next few decades.
Wildlife species description and significance
Eastern Baccharis is a perennial, salt marsh shrub of the Aster family. In Canada, it is 1 to 3 metres tall and deciduous with alternate gray-green leaves. Male and female flowers occur on different plants. It blooms in late summer with inflorescences of tiny flowers that can be very numerous on larger shrubs. The brilliant white pappus (bristles) on the seeds makes female plants easy to detect in late summer and early fall.
In Canada, Eastern Baccharis is rare, localized and 400+ km disjunct from the next nearest occurrence in northern Massachusetts. Eastern Baccharis is the only native representative of its genus and subtribe in Canada. The species is used horticulturally in the United States. Baccharis species contain an array of chemicals used medicinally, including some with potential for cancer treatment, but formal investigation of their properties has been limited. American First Nations have used some species in the treatment of sores and wounds, and as antibacterials and emetics. Eastern Baccharis has been introduced to and has become a problematic invasive in Mediterranean Europe and Australia and it is an agricultural weed in some U.S. states.
Distribution
Eastern Baccharis is native along the Gulf of Mexico south to Veracruz, Mexico and along the United States east coast north to northern Massachusetts. Southward, it occurs inland to Oklahoma, Arkansas, Tennessee and the Piedmont east of the Appalachians, although some of this distribution represents post-European colonization. It is also native in Cuba and the Bahamas. Canadian occurrences are restricted to a 25 km stretch of coast in extreme southwestern Nova Scotia. Populations are dominated by large, mature individuals, suggesting long-term occurrence in Nova Scotia.
Canadian distribution of Eastern Baccharis in extreme southwestern Nova Scotia, with subpopulation names.
Source: November 2011 COSEWIC Status Report.
Habitat
In the U.S., Eastern Baccharis occurs in a variety of moist or disturbed habitats. In Canada, it is restricted to open margins of well-developed salt marshes within harbours or bays that provide protection from wind and waves. It occurs in or near the transition zone to coastal forest with predominantly graminoid vegetation and shrubs 0.5 m to 2 m in height. Climate likely limits its extent of occurrence. Oceanic currents moderate the climate of the coastal zone of southwestern Nova Scotia, especially the area around Yarmouth where Eastern Baccharis occurs, the warmest Canadian winters outside of southern British Columbia, with temperatures considerably milder than the coast of Maine at the same latitude.
Biology
In Nova Scotia, Eastern Baccharis flowers from late July through mid- or late September. Females can produce more than one million seeds. Mature achenes (fruits) are wind- and water-dispersed, aided by the attached pappus. Achenes mature in late August or September, with most having dispersed by late October. In Nova Scotia (but not in the southern U.S.), leaves are deciduous in late October and November, later than most associated shrubs.
Seedlings in Nova Scotia have been observed very infrequently, suggesting establishment from seed is uncommon. Large individuals in Nova Scotia can have trunks up to about 10 cm diameter, suggesting considerable age, and new shoots sprout from the bases of mature shrubs, suggesting that individuals could persist for decades or longer. Eastern Baccharis also spreads vegetatively via the rooting of low branches. Seed banking is likely not significant because seeds have limited dormancy, but seeds can survive a minimum of two years if buried.
Population sizes and trends
The total number of mature individuals in Canada is estimated at 2850 and is probably quite completely documented. Three populations are known, with an additional site (West Pubnico) having only one known individual. These populations are divided into 9 subpopulations, two of which support ~88% of the Canadian population.
Population trends are not documented but are likely fairly stable. Only relatively small and localized development impacts have thus far occurred, but development is active or imminent in some populations and a future threat in others.
Threats and limiting factors
Habitat loss from coastal development, primarily for cottages or residences, is the only imminent threat. Development has been extensive on Nova Scotia’s Atlantic coast in the past 30 years, causing vast increases in land values. Eastern Baccharis occurs in aesthetically attractive coastal habitats and most occurrences are within a few hundred metres of good roads. Its habitat along the margin of coastal forest makes it especially prone to clearance by landowners seeking water views or access. It is, however, somewhat protected from development in many sites, including the two large subpopulations, because it occurs on islands within salt marshes for which creating road access would be expensive or against environmental regulations.
Death of individual plants from apparent saltwater inundation was observed very locally and habitat loss from sea level rise may be a future threat. Localized impacts from cattle grazing were also observed at one site.
The extreme concentration of the population (~88% of total) into two dense areas of occurrence totaling 11.5 ha means that development, sea level rise or chance events in those areas could substantially reduce the entire Canadian population. Observations suggesting limited recruitment from seed increase the significance of any threat that would remove mature individuals.
Protection, status, and ranks
Eastern Baccharis presently has no legal protection in Canada, although a provincial status report is being prepared, which could lead to legal protection under the Nova Scotia Endangered Species Act. No Canadian populations are within protected areas.
Eastern Baccharis is listed by NatureServe as globally secure (G5) with a national status rank of secure (N5) in the United States and critically imperilled (N1) in Canada. In Nova Scotia, it has a regional rank of critically imperilled (S1) and a National General Status rank of May Be At Risk, which equates to a “Red” rank under the Nova Scotia Department of Natural Resources provincial system. In the United States, it is considered rare only in Rhode Island where it is imperilled (S2) and Pennsylvania where it is Vulnerable (S3) and designated “Rare”.
Scientific name
Lophiola aurea
Taxon
Vascular plants
COSEWIC status
Special Concern
Canadian range
Nova Scotia
Reason for designation
In Canada, this Atlantic Coastal Plain plant is found only in Nova Scotia at a few lake shores and wetlands. The Canadian population primarily reproduces vegetatively and is genetically distinct and geographically disjunct from the nearest populations in New Jersey 800 km to the south. Revisions to the COSEWIC assessment criteria since the species’ last assessment account, in part, for the change in its risk status. Recent intensive surveys have also determined that the population is larger than previously thought. However, the species is subject to ongoing threats from development and habitat alteration.
Wildlife species description and significance
Goldencrest (Lophiola aurea) is a perennial herb within the Bloodwort Family (Haemodoraceae).
Plants arise from a rhizome with the erect, linear, blue-green leaves arranged predominantly in basal rosettes. Stems terminate in a single, densely white-woolly, branched inflorescence with yellow flowers that develop into round, many-seeded capsules.
Goldencrest is the only member of a distinctive genus and is globally uncommon with a very small range. It co-occurs in southern Nova Scotia with a large suite of other disjunct southern species of the Atlantic Coastal Plain, many of which are rare in Canada, including Redroot and Long’s Bulrush. It is exceptionally disjunct among this suite of species, with Nova Scotia populations separated by 800+ km from the nearest known sites in New Jersey.
Distribution
Goldencrest is endemic to the Gulf and Atlantic Coastal Plains. In the United States, it is known from Louisiana to Georgia, North Carolina, Delaware (where it is extirpated), and New Jersey. In Canada, the nine populations (seven known extant) are restricted to two regions of southern Nova Scotia.
Canadian range of Goldencrest. Arrows indicate presumed or potentially extirpated sites.
Source: May 2012 COSEWIC Status Report.
Habitat
In Canada, Goldencrest occurs on open lakeshores and graminoid-dominated peatlands. Low nutrient, acidic conditions prevail and disturbances such as flooding, wave action and ice scour prevent dominance of more competitive species. Lakeshore substrates are generally peaty, but often with only a thin organic layer over sand, gravel and cobble or bedrock. Elsewhere, the species is found on wet acidic soils in bogs, pocosins (freshwater wetlands with deep sandy and peaty soils), wet savannahs, pine barrens and sometimes in nearby anthropogenically disturbed habitats such as roadside ditches.
Biology
Goldencrest spreads extensively through rhizome and stolon growth. In Canada, it flowers in August and September. Seed banking is not documented but is plausible given the fluctuating lakeshore habitat in which the species occurs. Seedlings have not been observed in Canada, although little effort has been made to find them. Generation time is estimated at 3–5 years based on field observations suggesting vegetatively derived rosettes likely require several years before being capable of reproducing vegetatively. Individual clones appear very long-lived, potentially on the scale of decades.
Population sizes and trends
The total Canadian population includes hundreds of thousands of rosettes, although the number of genetic individuals is certainly much lower. Populations at Ponhook Lake (including Little Ponhook Lake) and Shingle Lake include about 93% of the ~75 known locations. Populations on these lakes are almost certainly slowly declining with shoreline development. Many of the several hundred cottages and residences on their shores have been built in the last 15 years. Shoreline development currently occupies no more than about 6% of shorelines on these lakes, and has likely reduced populations by less than 6% because development does not necessarily eliminate individual occurrences.
Other extant populations are relatively unthreatened and their populations have probably been stable in the past 15 years, although major declines from historical impacts are documented at Tiddville. The population at Brier Island has not been seen since 1985 and is presumed extirpated because of habitat change. The population at Sandy Cove, last documented in 1949, may be extant, but no subsequent searches are documented.
Threats and limiting factors
Shoreline development is the most serious threat to Goldencrest populations. The threat of shoreline development has been mitigated somewhat by the creation of a provincial nature reserve.
Other potential future threats are eutrophication, invasive species and peat mining. Historical impacts that are not current threats include water level management through damming of lakes and drainage of peatlands, diatomaceous earth mining, and off-road vehicle disturbance.
Protection, status, and ranks
In 2000, Goldencrest was listed as Threatened under the federal Species at Risk Act and the Nova Scotia Endangered Species Act. It bears a NatureServe rank of Apparently Secure (G4) globally. In Nova Scotia and Canada, Goldencrest is ranked as Imperilled (S2 and N2) with a General Status rank of At Risk, or “Red” under the Nova Scotia Department of Natural Resources’ provincial ranks. In the United States, it is Apparently Secure (N4?), being known from seven states, in five of which it is rare or extirpated.
About 25% of the Ponhook Lake occurrences are on Crown land within Ponhook Lake Nature Reserve (representing ~10% of the Canadian population), granting them protection under the provincial Special Places Protection Act. Likewise, roughly 25% of sites on Shingle Lake are on Crown land and not available for development (representing an additional 10% of the Canadian population).
Scientific name
Ursus arctos
Taxon
Mammals
COSEWIC status
Special Concern
Canadian range
Yukon, Northwest Territories, Nunavut, British Columbia, Alberta, Saskatchewan, Manitoba
Reason for designation
The global distribution of this large-bodied carnivore has declined by over 50% since the 1800s, with western Canada representing a significant core of the current North American range. A habitat generalist, its distribution and relative abundance in the absence of humans is largely driven by habitat productivity and seasonality. It is highly sensitive to human disturbance and is subject to high mortality risk in areas of human activity and where roads create access. Population estimates in much of the range are highly uncertain; the Canadian population is estimated at 26 000, but the number of mature individuals is uncertain and could be close to 10 000. While there is no evidence of a decline in the overall population during the past 20 years and increasing numbers of records indicating some range expansion in the north, a number of populations in the southern extent of its range in Alberta and southern BC are known to be declining and there are concerns about unsustainable mortality rates there and in parts of Yukon. There is strong evidence of genetic fragmentation in the southern parts of its range where some populations are increasingly isolated and subject to demographic stochasticity. Their poor condition in some parts of the range, combined with their naturally low reproductive rates and increasing pressures of resource extraction and cumulative impacts in currently intact parts of the range, heighten concern for this species if such pressures are not successfully reversed.
Wildlife species description and significance
The Grizzly Bear (Ursus arctos) is believed to have crossed over from Asia to North America 50 000–100 000 years ago. Conspecific with extant Brown Bears in Europe and Asia, it is a large ursid, with body sizes in Canada ranging from 100–150 kg for adult females to 180–270 kg for adult males. Grizzly Bears have a heavy, dish-shaped skull with dentition indicative of both a predator and herbivore (large canines and crushing molars), a robust body with long fore-claws, and powerful digging muscles that give the species its characteristic shoulder hump. Colour ranges from blonde through shades of brown to nearly black, with the sometimes silver-tipped nature of the fur giving the species a ‘grizzled’ appearance.
In Western and Aboriginal cultures, the Grizzly Bear is a popular, revered, and sometimes feared animal. The species is often considered a flagship or umbrella species for conservation planning, and few mammals typify Canadian wilderness in as many minds as does the Grizzly Bear. Grizzly Bears interact directly with humans, cause real and perceived conflicts over property, and can endanger human life. Although relatively few people hunt Grizzly Bears, the species is a highly prized trophy animal. The Grizzly Bear can also be an important part of subsistence hunting by some Aboriginal people for both food and cultural purposes.
Distribution
The Grizzly Bear occurs in Canada, the United States, and in Europe and Asia. Current records of occupancy exist for approximately 48 countries. Many Eurasian populations are insular, small, and endangered.
All living Grizzly Bears in Canada comprise the continuous ‘Western’ population (BC, western Alberta, Yukon, Northwest Territories [NT], mainland Nunavut and parts of the southwest Canadian Arctic Archipelago, northern Saskatchewan, and northeast Manitoba). The Western population occupies an estimated area of 2.98 × 106 km². Observations indicate some expansion of the distribution of Grizzly Bears northwards and eastwards in Northwest Territories, Nunavut, northern Saskatchewan, and northern Manitoba, although a lack of systematic surveys tracking occupancy over time in these areas prevent quantification of such trends. The bears occupying the Prairies, previously assessed by COSEWIC as an independent population, are now considered to have formed part of the Western population. The Ungava population of Grizzly Bears, which once occupied a discrete unit in northern Quebec and Labrador at the time of European colonization, has not been recognized by COSEWIC prior to this report.
Approximate boundaries of the current and historic (i.e., 19th century) distribution of the Grizzly Bear in North America, with contours of relative density.
Source: Modified from the May 2012 COSEWIC Status Report (map produced by P. McLoughlin).
Habitat
The Grizzly Bear is a habitat generalist. Grizzly Bears occur from sea level to high-elevation alpine environments. The species occupies habitats as diverse as temperate coastal rain forests, alpine tundra, mountain slopes, and upland boreal forest, taiga, dry grasslands at the fringe of the Prairies and in central BC, and the Arctic tundra. Grizzly Bear habitat associations are strongly seasonal and typically reflect local plant development and prey concentrations. In mountainous regions, Grizzly Bears may undertake seasonal elevational migrations.
Biology
Grizzly Bears are omnivores with adaptations to digging and rooting, grazing, and hunting. In some areas they are effective predators of ungulates such as Moose, Elk, and Caribou; Pacific-coastal bears feed heavily on spawning salmon, and arctic Grizzly Bears scavenge along shorelines where they may feed on whale and seal carcasses, or even hunt seals. Grizzly Bears use refuse and livestock as food sources if they are available and accessible. Females usually have their first litters at 6 years of age; litter sizes are 1–3 cubs, and intervals between litters are commonly 3–4 years. Natural longevity is around 20–30 years. Grizzly Bears have large home ranges, averaging 1 800 km² for males and 700 km² for females; however, home range size varies widely across Canada, showing an inverse relationship with habitat productivity. Grizzly Bears den in winter and enter hibernation (dormancy) for up to 7 months, with length of hibernation related to latitude. Cubs are born in the den in January or February.
Population size and trends
Worldwide, Grizzly Bear range has decreased by about 50% since the mid-1800s; it has lost 98% of its range in the lower 48 states of the US. The species was extirpated by the late 19th–early 20th century from much of the dry interior of southern British Columbia (BC), the Prairies of Alberta, Saskatchewan, and Manitoba, and the Ungava region of Quebec and Labrador. The Western population is currently estimated to number about 26 000 animals, of which about 11 500 are mature individuals.
However, estimates of Grizzly Bear population size and trends are uncertain in Canada, and are mostly based on expert opinion or extrapolations of estimates from small study areas to include large geographic regions. BC has the largest number of Grizzly Bears, with approximately 15 000 animals. The latest estimates include 6 000–7 000 bears in Yukon, 3 500–4 000 in NT, 700 in Alberta and between 1 500 and 2 000 in Nunavut. A few Grizzly Bears now occur in tundra regions of northeast Manitoba. Historical numbers in Canada are unknown, but were certainly much higher. The overall Western population is probably stable since 1990, when the first comprehensive and Canada-wide population inventory was reported, although there have been declines in Alberta, and possibly southern BC and in some parts of Yukon. On the other hand, some expansion of Grizzly Bear range in NT, Nunavut, Saskatchewan, and Manitoba appears to be underway. Population and trend information for the Western population is not available prior to 1990.
Threats and limiting factors
In the absence of human interference, the density of Grizzly Bears is largely determined by habitat productivity (food). However, anthropogenic mortality has important influences on area of occupancy and underlies functional habitat loss throughout much of the species’ range. Bears generally avoid humans and experience higher rates of mortality near anthropogenic features like roads and residential developments. Human activity is believed to lead to fragmentation and isolation of demographic units, whereby population dynamics may become determined by stochasticity in survival and reproduction irrespective of other factors, increasing chances of local extinction. Populations in BC, Yukon, NT, and Nunavut are subject to legal hunting, and all regions support and/or formally recognize the right to First Nations, Métis, and/or Inuit subsistence hunting. Bears that are killed by humans die because of legal hunting, defence of life and property, and poaching and vehicle and train collisions. Undocumented killing remains an important problem for managers. Evidence of human-caused mortality from all sources appears to be consistent with a stable population of Grizzly Bears at the scale of the Western DU; however, at local scales (in Alberta, southern BC, and parts of Yukon) recent mortality trends indicate real or suspected declines. At high densities, in addition to food, Grizzly Bears may also be limited by intraspecific predation or conflict. Effects of climate change on habitat availability for Grizzly Bears and associated effects on seasonal food supply have yet to be quantitatively studied; hypothetical mechanisms are varied and unclear, and projected net effects uncertain.
Protection, status, and ranks
The legal status of Grizzly Bears is as a “Big Game” species in the provincial and territorial wildlife legislation of British Columbia, Yukon, the Northwest Territories, and Nunavut. Grizzly Bears lack specific legal status in Manitoba, Quebec, and Newfoundland and Labrador, other than that generally afforded to wildlife. The Grizzly Bear population in Alberta was recently listed as Threatened under Alberta’s Wildlife Act (June 2010), which resulted in a ban on licensed hunting of the species in that province. The species was assessed as Sensitive in the 2010 Wild Species General Status report, the same national conservation status as in 2005. In British Columbia, Yukon, Northwest Territories, and Nunavut, Grizzly Bears had a General Status conservation rank of Sensitive in 2010. In Alberta, the conservation status rank was May be at Risk in 2010, whereas in Saskatchewan and Manitoba it was Extirpated. The 2010 General Status conservation rank for Newfoundland and Labrador was “Not Assessed”. No rank was given for Quebec. Approximately 7.1% of the range currently occupied by the Grizzly Bear in Canada is classified as ‘protected’ from human activity (to varying degrees) by federal, provincial, or territorial governments.
Scientific name
Dalea villosa
Taxon
Vascular plants
COSEWIC status
Special Concern
Canadian range
Saskatchewan, Manitoba
Reason for designation
A perennial, herbaceous legume that inhabits sand dune landscapes within the prairies of south-central Saskatchewan and southwestern Manitoba. Threats to the extent and quality of habitat continue, including a lack of fire allowing encroachment of competing vegetation, invasive alien plant species, recreational traffic, sand extraction as well as a general decline in open sandy habitat. However, a larger population size is now known due to greatly increased survey effort, and as a result the level of risk is now thought to be much reduced.
Wildlife species description and significance
Hairy Prairie-clover (Dalea villosa) is member of the Fabaceae (pea) family. It is a perennial with a woody taproot and stem base. Hairy Prairie-clover is a sand dune specialist and, as a nitrogen-fixing legume, would be an important source of nutrients in an otherwise somewhat impoverished habitat. In the United States, the species has been developed as a horticultural species.
Distribution
Hairy Prairie-clover is restricted to the Great Plains region of North America. In Canada it is distributed from south-central Saskatchewan to southwestern Manitoba and extends southward into the United States to New Mexico and Texas and eastward to Michigan. Within its Canadian range, it is found only in sand or sand dune complexes and so distribution is limited to these habitats. To date, it has been found in the areas of Dundurn Sand Hills and the Mortlach/ Caron area in Saskatchewan and Lauder, Routledge, Carberry, Treesbank, and Portage Sandhills in Manitoba.
Canadian occurrences of Hairy Prairie-clover.
Source: November 2011 COSEWIC Status Report.
Habitat
Hairy Prairie-clover is found locally on active sand or sandhill blowouts although it also tolerates partially stabilized sandy sites. Habitat generally includes some element of open or active sand including old deltas of glacial lakes formed 10,000 to 17,000 years ago. During this time, all of the modern sites of Hairy Prairie-clover were connected by a series of glacial lakes and their spillways.
Biology
Hairy Prairie-clover is a warm-season species that is well-adapted to dry environments. Flowers appear in July-August and are insect-pollinated. Seed is set in late August to September and seed is dispersed by wind, rodents and deer. Deer are the major grazer, while sheep are the most threatening domestic grazer of Hairy Prairie-clover.
Population sizes and trends
The largest known population exists in the Dundurn area, with roughly 110 000 plants. Sites in the Mortlach/Caron (SK), Shilo/Treesbanks (MB) and Lauder/Routledge (MB) areas each have on the order of 10 000 plants. A smaller population of approximately 2 000 plants occurs in the Portage Sandhills (MB). Total estimated Canadian population size is approximately 145 000. Trends are difficult to discern at this point because the majority of these populations have been found only in the past decade.
Threats and limiting factors
The greatest threats to Hairy Prairie-clover are dune stabilization, in part due to changes in ecological processes such as fire suppression and disruption of natural grazing regimes, and the introduction and spread of invasive species. Many of the southern sites have been invaded by Leafy Spurge, and some are threatened by Smooth Brome and Crested Wheatgrass. Further, invasive species may be introduced through hay for deer feed. Recreational activities are problematic; in particular, unrestricted all-terrain vehicle activities and hiking are thought to have crushed plants. Also due to the nature of the sites, sand removal by humans results in a complete loss of habitat and presumably the seed bank.
Protection, status, and ranks
The Hairy Prairie-clover is listed as Threatened under Schedule 1 of the Canadian Species at Risk Act, as of June 2003. In Saskatchewan, the plant has been protected since 1999 under The Wildlife Act. In Manitoba, Hairy Prairie-clover has been protected since July 2007 on all lands under the Endangered Species Act. The plant is protected also in Spruce Woods Provincial Park through the Manitoba Provincial Park Act. In Saskatchewan, the Dundurn Sand Hills population is partially protected because it occurs in 17-Wing Detachment Dundurn, which restricts public access.
A Recovery Strategy is being drafted identifying critical habitat. Within Saskatchewan, recommendations regarding Hairy Prairie-clover are listed in the Saskatchewan Activity Restriction Guidelines. On federal lands, recommendations regarding Hairy Prairie-clover are listed in the activity set-back distance guidelines for prairie plant species at risk.
Globally, both the full species and variety of Hairy Prairie-clover are ranked secure (G5T5) by NatureServe. Its national status in Canada is imperilled to vulnerable (N2N3), and in Saskatchewan it is ranked critically imperilled (S1). In Manitoba, it is ranked imperilled to vulnerable (S2S3). Hairy Prairie-clover is not on the IUCN Red List of Threatened Species.
The conservation status has not been assessed nationally in the United States by NatureServe or by 11 of the states where it occurs. In Montana, Iowa and Wyoming, it is ranked critically imperilled (S1); and in Wisconsin it is ranked imperilled (S2).
Scientific name
Setophaga citrina
Taxon
Birds
COSEWIC status
Not at Risk
Canadian range
Ontario
Reason for designation
In Canada, the range and abundance of this forest-nesting species have increased substantially since the species was last assessed. The species has also experienced a significant long-term increase in abundance in the core of its range in the United States, so there is an outside source for rescue. However, habitat degradation at breeding sites and habitat loss and degradation at migration stopover sites and on the wintering grounds are potential threats.
Wildlife species description and significance
This small yellow songbird is readily identified by its distinctive plumage and vocalizations. Adult males have a characteristic black hood but this feature is reduced or lacking in adult females.
Distribution
The Hooded Warbler is a long-distance migrant that breeds in eastern North America and winters in Mexico, Central America and the Caribbean. The breeding range of this species has been expanding northwards for at least 40 years. The Canadian breeding distribution is restricted to southern Ontario, where it is considered to be a rare or locally uncommon breeder.
Breeding and non-breeding ranges of the Hooded Warbler.
Source: "Birds of North America Online" maintained by the Cornell Lab of Ornithology, Ithaca, NY.
Habitat
The Hooded Warbler typically nests in shrubs associated with small canopy-gaps within large tracts (>100 ha) of mature deciduous or mixed forests. High densities can occur following selective logging, provided many mature trees remain. On the wintering grounds, there is strong sexual segregation by habitat with males preferring closed canopy forests and females preferring more open shrubby habitats.
Biology
This insect-eating passerine begins breeding when it is 1 year old. Hooded Warblers typically lay 3 or 4 eggs in cup-shaped nests, 1 m from the ground, that are frequently parasitized by Brown-headed Cowbirds. Nest predation rates are high (e.g., in Ontario 30–50% of nests are depredated). Even so, this species often succeeds in raising two broods to fledging in a single breeding season (early May through September in Ontario). Hooded Warblers rarely return to breed at their natal site, whereas adults show relatively strong fidelity to breeding and wintering sites. The expected life span is short, and the average age of breeding adults is about 2–3 years.
Population sizes and trends
Data from all sources show a consistent pattern of strong increases in the abundance and distribution of the Hooded Warbler population in Canada. The Canadian population is currently estimated to be between 1 000 and 2 000 breeding birds (much less than 1% of the global population). The Ontario Breeding Bird Atlas (OBBA) showed a strong population increase, from 21 atlas squares (10 km² survey blocks) with breeding evidence during 1981–85, to 81 squares during 2001–05, although with relatively greater search effort in the second atlas.
Directed searches at known and potential breeding locations in southern Ontario in 1997, 1998, 2002, and 2007 also documented ongoing increases in population size, number of occupied sites, and breeding distribution. The 1997 survey found 88 territorial males while the 2007 survey recorded at least 436 at 89 sites. These surveys covered most but not all areas with known or potentially occupied habitat in southern Ontario.
Threats and limiting factors
Given the observed increase in the Hooded Warbler population in Canada, habitat availability does not appear to be a limiting factor at present. Climate change appears to be an important factor in the observed range expansion. Some studies in Ontario have found low productivity and suggested that some areas may be acting as ecological sinks. However, there is also evidence that the Hooded Warbler population is very dynamic, and is characterized by high levels of immigration and emigration in response to habitat quality. Provided that there is an ongoing supply of suitable habitat, then it is likely that the Hooded Warbler population will continue to be stable, or increasing. Loss and degradation of habitat at migration stopover sites and on the wintering grounds have been identified as potential threats, but the magnitude of these threats is unknown.
Protection, status, and ranks
The Hooded Warbler is protected under the Migratory Birds Convention Act in Canada and the United States. It was assessed by COSEWIC in 1993 and again in 2000 and then listed as Threatened under the federal Species at Risk Act when the Act came into force in 2003. It is also listed as Special Concern under Ontario’s Endangered Species Act, 2007. This species is considered globally secure by BirdLife International (Least Concern) and NatureServe (G5).
The current draft of the proposed federal Recovery Strategy identifies 56 sites in Ontario with critical habitat for this species, with a total area of about 9000 ha. None of the proposed critical habitat is on federal lands. Over half of the sites are on publicly owned lands, consisting mostly of managed forests that are not formally protected.
Scientific name
Magnipelta mycophaga
Taxon
Molluscs
COSEWIC status
Special Concern
Canadian range
British Columbia
Reason for designation
This large slug, up to 80 mm in length, is regionally endemic to the northern Columbia Basin in western North America. About half of the species’ global range extends into southeastern British Columbia. It occurs in a number of widely separated habitat patches and is confined to cool, moist places in coniferous forests at mid- to high elevations. While hundreds of sites have been searched for slugs and land snails within the range of this slug, mostly within the past decade, as of November 2010 there are only 13 records for it in Canada. Since the 1960s its habitat has become increasingly fragmented. The number and variety of threats including logging, recreational developments and activities, wildfire, and changes in moisture regimes caused by climate change increase the level of risk.
Wildlife species description and significance
The Magnum Mantleslug is the sole member of the genus Magnipelta. It is a large slug up to 80 mm in length. Its most distinctive feature is a large mantle, which covers most of the back. The body is tan-brown with uneven black spotting; there is an irregular dark stripe on each side of the mantle. The species is regionally endemic to the northern Columbia Basin and adjacent mountains, an area that contains many unique plants and animals.
Distribution
The Magnum Mantleslug occurs in southeastern British Columbia (BC), northwestern Montana, northern Idaho, and extreme northeastern Washington. About half of the species’ global distribution is in BC; the remainder is mostly in Montana. In BC, the species distribution extends from the Canada–U.S. border north to Wells Gray Provincial Park and from near Trail east to Fernie. This distribution encompasses portions of the Rocky Mountains, Columbia Mountains (Purcell, Selkirk, and Monashee ranges), and Shuswap Highlands. The distribution of the species is extremely patchy within this large range, possibly reflecting the availability of suitable moist habitats and low dispersal abilities of the slugs. As of November 2010, there are 13 records of the species from scattered sites, assigned to nine populations. Hundreds of sites have been searched for slugs and land snails within the distribution of this species, mostly within the past 10 years.
Canadian distribution of Magnum Mantleslug, based on records from 1992–2010.
Source: May 2012 COSEWIC Status Report.
Habitat
The Magnum Mantleslug occupies coniferous forests at mid- to high elevations and requires cool, moist conditions. In BC, the species has been found in Interior Cedar-Hemlock and Engelmann Spruce–Sub-alpine Fir biogeoclimatic zones at elevations of 800–2 060 m. The slugs inhabit very moist microsites, often with abundant herbaceous vegetation such as found in splash zones of cascading creeks and avalanche chutes, but also occur on the forest floor under heavily shaded forest canopy. The slugs are often associated with decaying logs and other coarse woody debris and have also been found under rocks in stable talus in moist situations.
From 1960 to present, habitats of the Magnum Mantleslug in Canada have become increasingly fragmented mainly due to logging, agriculture, ranching, mining, hydro development, transportation corridors and land conversions to residential areas. Considerable areas of mid- to high elevation forests are still intact due to a network of protected areas and inaccessible terrain, but logging and other resource extraction activities continue to expand in higher elevation forests.
Magnum Mantleslug habitat.
Biology
Very little is known of the life cycle of the Magnum Mantleslug. The species is hermaphroditic, possessing both female and male reproductive organs, but exchange of sperm with other individuals, rather than self-fertilization, is probably the norm similar to most other slugs. The slugs lay eggs and can live more than 1 year; whether individuals are capable of reproducing in their first year is unknown but possible. The slugs are active during moist conditions from spring to autumn and seem to prefer substrate temperatures of 12–15°C. Their requirements for cool, moist microhabitats probably limit their distribution within the landscape and increase their vulnerability to human activities that alter hydrology or forest floor microclimates. The species is expected to have poor dispersal abilities similar to other terrestrial gastropods.
These slugs exhibit an unusual behaviour in response to disturbance. If provoked, the slug is prone to spread its large mantle in a wing-like fashion. This behaviour perhaps startles a predator or exaggerates the slug’s body size, making it appear too large to swallow.
Population sizes and trends
No estimates of population sizes or trends are available. There are 13 records of the species from BC, representing a total of only 15 individuals, from 1992–2010. New sites continue to be found with increasing search effort. However, it is clear that the species’ distribution is extremely uneven, even in apparently suitable habitats. Some habitat patches are small, raising questions about long-term viability of the populations. All six sites where the species had been found previously were visited in 2010; the species was found only near one of the sites, as well as at two new sites in the intervening areas. Given the species’ patchy distribution across the landscape, poor dispersal ability, and the scattered distribution of suitable moist habitat patches, it is highly probable that populations have been lost over the past century and continue to be lost as a result of habitat degradation.
Threats and limiting factors
At known sites, the species is threatened by logging, recreational developments and activities, wildfire, and climate change. Logging is pervasive throughout the species’ range, and five of 10 occupied sites are on forestry lands. Logging alters temperature and moisture regimes on the forest floor and can disturb or destroy habitat patches. Logging roads have increased public access to the backcountry, including off-road vehicle use that compacts soil and can destroy habitat patches used by the slugs. Recreational developments and activities, such as ski hill developments, are localized but expanding within the species’ range. Infrastructure development and heavy recreational use can result in soil compaction and damage to understorey vegetation, posing threats to slug habitats. Strip-mining for coal is expanding in the southeastern part of the species’ range in Canada.
The frequency and extent of wildfires is expected to increase with climate change and Mountain Pine Beetle infestations that are sweeping across interior BC. Terrestrial gastropods are thought to be sensitive to fire, which can decimate habitats and individuals, but the ability of the Magnum Mantleslug to survive fire events and persist in burned areas is unknown. Increased mortality due to the toxic effects of fire retardant chemicals is also a potential threat. Climate change is predicted to result in shifts in habitats and ecosystems over the next decades. Species occupying higher elevation habitats, such as the Magnum Mantleslug, might be especially vulnerable to shifts in habitats and ecosystems along altitudinal gradients, but the magnitude of such effects is uncertain.
Protection, status, and ranks
The Magnum Mantleslug has no official protection or status under the federal Species at Risk Act, BC Wildlife Act, or other legislation. It is ranked by NatureServe as follows: Global status: G3 – vulnerable; United States: N3 – vulnerable; Canada: N2N3 – imperiled to vulnerable; Idaho: SNR – not assessed; Montana: S1S3 – critically imperiled to vulnerable; Washington: S2 – imperiled; British Columbia: S2S3 – imperiled to vulnerable. In addition, the species is on the provincial blue list of species at risk (currently under reassessment).
The species has been recorded from Mount Revelstoke National Park, two provincial parks (Wells Gray and Stagleap), and a recently protected area owned by the Nature Conservancy of Canada. The remaining known sites are on private or provincial forestry lands and private resort properties.
Scientific name
Desmognathus fuscus
Taxon
Amphibians
COSEWIC status
Endangered
Canadian range
Ontario
Reason for designation
This species is restricted to one small creek sustained by groundwater seepage on the steep slope of a gorge vulnerable to erosion, atmospheric deposition of pollutants and habitat acidification. The population is small and susceptible to ecological, demographic and genetic stochasticity.
Wildlife species description and significance
The Northern Dusky Salamander (Desmognathus fuscus) is a member of the family Plethodontidae (lungless salamanders). Adults are usually brownish with a light dorsal stripe that continues onto the first portion of the tail. The body is sparsely covered with dark spots that are concentrated on the sides and becomes white or grey on the underside. Old individuals tend to be uniformly dark brown or black. Younger life stages have five to eight pairs of dorsal blotches or spots. Both adults and larvae have larger hind legs than forelegs and a pale line extending from the eye to the rear of the jaw. The Northern Dusky Salamander is the most widespread representative of its genus in Canada.
Distribution
The Northern Dusky Salamander is distributed throughout the mountainous regions of eastern North America. The Canadian distribution accounts for about 5% of the global range and includes a small area in the Niagara Gorge in Ontario, three large areas in Quebec (the Adirondack Piedmont, the Appalachian uplift, and the north shore of the St. Lawrence River), and scattered areas in southern New Brunswick. Within its range, the Northern Dusky Salamander occurs discontinuously usually in high elevation, low-order streams, in forested habitat. There are two designatable units, the Carolinian DU in Ontario, and the Quebec/New Brunswick DU.
Canadian distribution of the Northern Dusky Salamander.
Source: May 2012 COSEWIC Status Report.
Habitat
The Northern Dusky Salamander inhabits the vicinity of springs, seepages, and small tributaries of clear headwater streams in forested habitats. The species takes refuge under protective cover (rocks, logs, moss or leaf litter) or in cool subterranean retreats near stream edges. It forages along the streamside, mostly in terrestrial habitat. Females usually nest in cryptic microhabitats near a stream’s source where soil is saturated. Larvae are strictly aquatic and remain in interstitial spaces among rocks of the streambed during their development. In winter, larvae remain in shallow running water, whereas adults retreat to subterranean refuges with constant water flow. Habitat availability and quality are optimal in undisturbed watersheds with abundant forest cover.
Biology
The Northern Dusky Salamander has a biphasic life cycle that includes an aquatic larval stage of 7 to 16 months, followed by a semi-aquatic adult stage. Sexual maturity is attained at 3 to 4 years of age. Mating takes place in the spring or fall and females lay eggs annually in late spring and summer. Fecundity increases with body size, and clutch size varies geographically between 8 and 45 eggs. Females remain with their clutches until they hatch 45 to 60 days after oviposition. Maximum life span is about 10 years.
Northern Dusky Salamanders are particularly vulnerable to water loss, and are most active at night. The threat of desiccation makes the species a poor overland disperser. Movements occur primarily along the stream channel usually within a few metres of water’s edge. Adult home range is small (0.1 m²–3.6 m²). The species consumes aquatic and terrestrial invertebrates opportunistically. It lacks defence mechanisms against predators, but is capable of tail breakage. Fish, snakes, crayfish, birds, small mammals and larger salamanders are the main predators of the Northern Dusky Salamander. Hybridization between Northern Dusky Salamanders and Allegheny Mountain Dusky Salamanders occurs infrequently.
Population sizes and trends
Although considerable sampling effort has been invested in some parts of the species’ Canadian range, current data do not allow an accurate estimate of population sizes or trends. In Ontario, the species is confined to a single small location in the Niagara Gorge. Estimates suggest the Ontario population size is likely fewer than 250 adults. The species is widespread in Quebec and New Brunswick; however, local densities are usually low. In each province six new populations have been discovered in the past few years as a result of increased targeted searches. Accordingly, the extent of occurrence has slightly increased, reflecting greater search effort rather than population growth or the establishment of new populations. On the other hand, some populations seem to have disappeared.
Threats and limiting factors
Changes in water supply and quality due to human activities are the main threats to the Northern Dusky Salamander in Canada. Decreased groundwater supply to the species’ habitat can be catastrophic to local populations. Artificial increase in discharged water volumes in some areas is also likely to disrupt salamander populations and reduce suitable microhabitats. Runoff water from urban, industrial and agricultural areas can contaminate groundwater and waterways. Heavy metal contamination from atmospheric deposition is likely responsible for the disappearance of the species in Acadia National Park in Maine. Stream acidification is also a concern to the species as nearly 40% of the mountain streams in the southern Appalachians show signs of acidification.
Timber harvesting, windfarms, and watershed urbanization reduce water supply, water quality and microhabitat availability. Siltation is one of the most adverse effects of timber harvesting because interstitial spaces used by salamanders for foraging, shelter, nesting, and overwintering are lost. At the watershed scale, urbanization has caused the disappearance of the Northern Dusky Salamander in Mount Saint-Hilaire National Park (Quebec) and other areas. Introduction of predatory fish, particularly Brook Trout, is a threat to the species.
Protection, status, and ranks
The Northern Dusky Salamander is listed as Endangered in Ontario and is protected under the Endangered Species Act, 2007. In Quebec, the species is likely to be designated Threatened or Vulnerable by the provincial government. Nonetheless, the provincial Act respecting conservation and development of wildlife (R.S.Q., c. C-61.1) prohibits collecting, buying, selling or keeping specimens in captivity. Article 22 of the provincial Environment Quality Act (R.S.Q., c. Q-2) offers protection against unregulated degradation of environmental quality. The Northern Dusky Salamander is designated as Sensitive in New Brunswick under the General Status of Species in Canada. It is protected under the New Brunswick Fish and Wildlife Act, which prohibits taking any wildlife into captivity, keeping wildlife in captivity, or selling, trading or purchasing any wildlife, without authorization from the Minister.
At the present time, nearly a quarter of Northern Dusky Salamander localities in Canada are secured in protected areas and by ownership agreements. More than 75% of the species’ observations do not fall under any type of habitat protection.
Scientific name
Efferia okanagana
Taxon
Arthropods
COSEWIC status
Endangered
Canadian range
British Columbia
Reason for designation
This Canadian endemic is known from only five locations within a very small area of south-central British Columbia. The species’ grassland habitat is limited and continues to be degraded. Threats include introduction and spread of invasive species, changing fire regimes, pesticide drift and unrestricted ATV use.
Wildlife species description and significance
Efferia okanagana Cannings (Okanagan Efferia – working common name) is a large (up to about 2 cm long), brown, bristly fly in the family Asilidae (robber flies). Both sexes have striking orange-golden bristles behind the eyes. In the male, the external genitalia at the tip of the abdomen are large and hammer-shaped; the last three visible abdominal segments are silver-white. The female has a long, sword-shaped ovipositor at the end of the abdomen. There are no subspecies known. The larva and pupa are unknown.
This robber fly is significant because it is one of the more obvious large invertebrates representative of the Antelope-brush ecosystem in Canada. Much of this habitat is threatened and, as yet, the fly is unknown from anywhere else in the world.
Distribution
The known global distribution of the fly is restricted to five locations (28 individual sites) in the Okanagan and Thompson valleys of south-central British Columbia, from Kamloops in the north, to Oliver in the south.
Global and Canadian distribution of Okanagan Efferia.
Source: November 2011 COSEWIC Status Report.
Habitat
The Okanagan Efferia is apparently restricted to dry grasslands growing on gravelly or sandy loam soils. Open soil is usually present, as is Bluebunch Wheatgrass. In the South Okanagan, the species has been found only in Antelope-brush steppe.
Okanagan Efferia habitat.
Biology
Robber flies are generalist predators of other insects, both as larvae and adults. The adults of Okanagan Efferia have been recorded capturing leafhoppers, click beetles, leafcutter and andrenid bees and ants, micromoths, flower flies, crane flies and robber flies. Prey is seized in the fly’s bristly legs and the prominent proboscis is inserted in the prey’s body. Paralyzing, proteolytic saliva is injected and the tissues are dissolved; the resulting fluid is sucked up by the fly. Eggs are laid in the empty glumes of the previous year’s wheatgrass inflorescences. It is assumed that, like most other robber flies, larvae feed on soil invertebrates such as beetle larvae. The larval period lasts 1–2 years; pupation evidently occurs in the last spring and the adults emerge in late April or early May.
The Okanagan Efferia has been collected or photographed from 17 April to 18 June, with most records falling in the middle weeks of May.
Population sizes and trends
Population sizes have not been estimated. Populations are patchily distributed in suitable habitat at the regional scale and density is extremely variable at the site scale. In appropriate habitat, thirty-minute searches can produce catches of up to 15 specimens; usually the range is 0 to 5. There is no direct information on population trends, although declines can be inferred from trends in habitat destruction. In the southern part of the species’ range, Antelope-brush steppe, the main habitat of the fly, has declined by two-thirds since European settlement.
Threats and limiting factors
Threats to the Okanagan Efferia include habitat loss or degradation (development, especially of vineyards; overgrazing by livestock; damage by vehicles), wild fires and related changes, invasive plants, climate warming, and pesticide effects.
There is no detailed information on limiting factors. There is an apparent, unmeasured correlation of the species’ presence with Bluebunch Wheatgrass growing on gravelly soils. The well-drained character of these soils, or some other features, may be limiting requirements of the soil-dwelling larvae. The only oviposition sites observed are the empty glumes in the old inflorescences of this grass species. Larvae feed on subterranean insect larvae and the availability of suitable prey may be limiting. Adults are opportunistic, general predators of flying insects and locating suitable prey is likely not limiting.
Protection, status, and ranks
Okanagan Efferia has no legal protection, except for that general protection it receives when living in parks and other provincially or federally protected areas and lands owned by non-governmental conservation organizations such as the Nature Trust of BC. The most significant protected areas where the species has been recorded are the Lac du Bois Grassland Protected Area near Kamloops, Kalamalka Lake Provincial Park near Vernon (BC Parks, British Columbia Park Act) and Nature Trust of BC properties at Okanagan Falls and Vaseux Lake. Three of the five locations and most of the collection sites are from the southern Okanagan in Antelope-brush steppe. Government and private conservation lands there protect 15% of the remainder of this habitat in BC.
The Okanagan Efferia is not ranked by the National General Status program. It is unranked globally by NatureServe and unranked provincially by the BC Conservation Data Centre.
Scientific name
Cryptantha minima
Taxon
Vascular plants
COSEWIC status
Threatened
Canadian range
Alberta, Saskatchewan
Reason for designation
This small herbaceous annual plant is limited in Canada to a small area of grassland habitat in southeastern Alberta and adjacent southwestern Saskatchewan. Though a larger range and population size are now known due to greatly increased search effort, the species remains under threat from residential and industrial development, agricultural activities, altered hydrological regimes, and a lack of fire and grazing which allows encroachment of competing vegetation, such as invasive species. The species’ extent and quality of habitat continue to decline and it is subject to extreme fluctuations in population size, which increases its vulnerability.
Wildlife species description and significance
Tiny Cryptantha is a small, bristly-haired annual plant that has tiny white flowers with yellow centres. The Canadian populations are the most northern occurrences of this species, and because these populations are disjunct from more southern populations, they could carry unique genetic variability that may contribute to adaptations and long-term persistence of the species.
Distribution
Tiny Cryptantha is native to North America. In Canada, the species is associated with river systems, mainly the South Saskatchewan River valley in the eastern half of Alberta and into western Saskatchewan. It also occurs near the lower Red Deer, lower Bow, Oldman and Lost rivers in Alberta and the Red Deer River in Saskatchewan. The closest occurrence outside Canada is a historical collection from Great Falls, Montana approximately 200 km from the southernmost Alberta population at Onefour. The species’ range in Canada represents less than 1% of its total range.
Distribution of Tiny Cryptantha in Canada.
Source: May 2012 COSEWIC Status Report.
Habitat
Tiny Cryptantha is found within about five kilometres of river systems, typically in sandy, level to rolling upland areas and sand dunes near valley breaks, valley slopes with up to 50% slope, and level or gently sloping terraces in valley bottoms, particularly in meander lobes where flooding provides more frequent disturbance. It requires habitats with low litter levels and a minimum of 10% bare soil for establishment. Periodic soil disturbance by wind, water, erosion or animals is required to open up the canopy and provide spaces for germination and establishment. However, areas that have repeated intense disturbance, such as actively eroding slopes, dunes and sandbars do not appear to support Tiny Cryptantha.
Tiny Cryptantha habitat.
Biology
Tiny Cryptantha is an annual that spends a large portion of its life cycle as a seed. It lacks a dormancy mechanism, but exhibits conditional dormancy in which germination is temperature and moisture dependent. The proportion of seeds deposited into the seed bank and the period of viability of seeds remains unknown.
Seeds are likely dispersed passively, with most falling close to the parent plant. There may also be dispersal by animals, wind and water. There is no means of asexual reproduction for this species.
Population sizes and trends
Twenty-five extant populations of Tiny Cryptantha exist in Canada. There are 22 in Alberta, two in Saskatchewan and one straddling the Alberta–Saskatchewan border. A third Saskatchewan population may have been misidentified or may be extirpated. Due to its annual life cycle, the timing of various surveys throughout the growing season, and a limited number of resurveys of known populations, population trends for the species cannot be fully assessed.
Threats and limiting factors
Availability of suitable habitat is limiting. Identified threats to Tiny Cryptantha include habitat loss and degradation as a result of residential development and oil and gas exploration. Cultivation and sand/ gravel extraction have also been identified as threats. Additional threats include modifications to natural processes through altered hydrological regimes and lack of grazing and/or fire, invasion by alien species, and the effects of climate change.
Protection, status, and ranks
Tiny Cryptantha is designated as Endangered under Schedule 1 of the federal Species at Risk Act. It is also listed as Endangered under the provincial species at risk legislation in Alberta and Saskatchewan, the two provinces where it occurs in Canada.
A large part of the Canadian population occurs in the Suffield National Wildlife Area where legal protection exists but ongoing petroleum exploration and development threatens the species.
Western Screech-Owl macfarlanei subspecies.
Scientific name
Megascops kennicottii kennicottii; Megascops kennicottii macfarlanei
Taxon
Birds
COSEWIC status
Threatened (kennicottii and macfarlanei subspecies)
Canadian range
British Columbia (kennicottii and macfarlanei subspecies)
Reason for designation
Kennicottii subspecies:
This small owl has shown serious declines in the southern part of its range in Metro Vancouver, Victoria and the Gulf Islands areas, where it has nearly disappeared over the last 10 to 15 years. Based on observed declines reported in Alaska, it has likely also declined in the northern part of its range, but the magnitude of the decline is unknown. The population is thought to be relatively small (less than 10 000 adults) and the owls face ongoing threats including predation from newly established populations of Barred Owls, and the removal of dead trees and snags, which serve as nest sites and roosts.
Macfarlanei subspecies:
The Canadian population of this owl is small, numbering between 350 and 500 adults, but is larger than previously estimated based on recent survey effort and has a much wider range in southern British Columbia than previously thought. The population has been apparently stable over the last 10 years, but faces ongoing threats especially from the loss of mature trees needed for nesting and roost sites. The loss of these trees is associated with urban and agricultural developments and degradation of riparian woodlands.
Wildlife species description and significance
The Western Screech-Owl, Petit-duc des montagnes in French, is one of two species in the genus Megascops in Canada. It is a small owl with distinct “ear” tufts and yellow eyes; sexes are alike. There are two distinct subspecies in Canada: the kennicottii subspecies along the Pacific coast and the macfarlanei subspecies in the valleys of the southern interior of British Columbia.
Distribution
The Western Screech-Owl is found at low elevations in Pacific coastal forests, and at lower elevations from the southern interior of British Columbia south through mountain valleys to northwestern Mexico. In Canada, it is found in coastal British Columbia (except Haida Gwaii) and in the valleys of southern British Columbia from Lillooet, Kamloops, Lumby, Slocan, Creston and Cranbrook south to the US border.
Habitat
The kennicottii subspecies is found in a variety of coniferous and mixed forests, but is often associated with riparian zones with Broadleaf Maple or Black Cottonwood. The macfarlanei subspecies is strongly associated with riparian woodlands dominated by Black Cottonwood, Water Birch or Trembling Aspen, usually located in a matrix of dry coniferous forests dominated by Ponderosa Pine or Douglas-fir. Both subspecies nest in natural tree cavities or holes excavated by larger woodpeckers, and will use appropriate nest boxes.
Range of the Western Screech-Owl in British Columbia. Range of interior species M. k. macfarlanei shown in black; that of coastal subspecies M. k. kennicottii shown in red.
Source: May 2012 COSEWIC Status Report.
Biology
The Western Screech-Owl is nonmigratory; pairs defend territories year-round. They are generalist predators, feeding primarily on small mammals and large insects, but also small birds, fish, frogs, and slugs. Young birds disperse from their natal territories in late summer.
Population sizes and trends
Populations of the kennicottii subspecies in southwestern British Columbia, especially around Metro Vancouver and Victoria, have all but disappeared in the past 10 to 15 years. Populations in northern Vancouver Island appear relatively healthy, but long-term trends are unknown. The subspecies has also likely declined in central and northern coastal forests, but the magnitude of the decline is unknown. Populations of the macfarlanei subspecies likely decreased throughout the 1900s because of habitat loss, but seem relatively stable or declining very slowly at present. The kennicottii subspecies in Canada is poorly known, but estimated to be about 1500–3000 individuals. The macfarlanei subspecies is less abundant, likely numbering 350–500 individuals.
Threats and limiting factors
Habitat loss is the primary threat to the macfarlanei subspecies and has likely affected the kennicottii subspecies as well. Predation by the newly arrived Barred Owl is thought to be the primary cause of significant population declines of the kennicottii subspecies on the south coast.
Protection, status, and ranks
The macfarlanei subspecies is listed as Endangered under the federal Species at Risk Act; the kennicottii subspecies is listed as a species of Special Concern based on the May 2002 COSEWIC assessments. In British Columbia, the species and active nests are protected from direct harm under the Wildlife Act; the macfarlanei subspecies is on the British Columbia Red List (potentially Threatened or Endangered) and the kennicottii subspecies is on the Blue List (Special Concern).
Scientific name
Icteria virens virens
Taxon
Birds
COSEWIC status
Endangered
Canadian range
Ontario
Reason for designation
This subspecies is a shrub-thicket specialist that occurs at the northern edge of its range in Canada. Its population in southern Ontario is localized and very small. Since the last status report was produced, declines have occurred in the Ontario population owing to habitat loss. The potential for rescue effect has also been dramatically reduced, because population declines are evident across most of the northeastern range of this subspecies.
Wildlife species description and significance
The Yellow-breasted Chat is regarded as an unusually large warbler. It has olive-green upper parts, a lemon-yellow chin, throat and breast, and a white belly and undertail coverts. It has a thick bill and a long, rounded tail and rounded wings. The face is greyish, with black lores and distinctive white “spectacles”. There are two subspecies – I. v. auricollis in the western half of North America and I. v. virens in the eastern half. During the breeding season, chats have a distinctive song characterized by repeated whistles, alternating with harsh chattering clucks and soft caws. The Yellow-breasted Chat is a flagship bird species for early successional shrubland habitats; members of this guild are declining widely in North America.
Distribution
Yellow-breasted Chats breed in North America, south of the boreal forest. The auricollis (western) subspecies breeds from southern British Columbia, Alberta and Saskatchewan, south discontinuously to northern Mexico. It occurs as far east as western Nebraska, western Kansas, and central Texas. The virens (eastern) subspecies breeds from the east-central Great Plains and eastern Texas eastward, and north to southwestern Ontario. Chats winter in the lowlands of eastern and western Mexico through Central America to western Panama.
In Canada, three populations are identified as separate designatable units: the Southern Mountain population of I. v. auricollis (British Columbia), the Prairie population of I. v. auricollis (Alberta and Saskatchewan), and the I. v. virens population (Ontario).
Breeding distribution of the Yellow-breasted Chat (virens subspecies) in southern Ontario, based on data from the Ontario Breeding Bird Atlas for the period 2001–2005. Squares with black dots are those in which the species was found in the first atlas period (1980–1985), but not in the second (2001–2005).
Source: Cadman, M.D., D.A. Sutherland, G.G. Beck, D. Lepage, and A.R. Couturier (eds.). 2007. Atlas of the Breeding Birds of Ontario, 2001-2005. Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature, Toronto, xxii + 706 pp.
Habitat
The Yellow-breasted Chat is a shrub specialist, occurring in dense riparian shrubland in western North America and early successional shrub habitats in the east. In British Columbia, the riparian habitat where chats live has been reduced by 87%. However, for the Prairie population, habitat may be increasing in Saskatchewan because of shrub succession. In Ontario, habitat has declined since the early 1960s, because of land conversion and successional change.
Biology
Nests are situated close to the ground in dense shrubby vegetation. If nests fail, females will attempt up to three replacement clutches in one breeding season. Loose coloniality may occur, as territories are often clumped. In British Columbia, I. v. auricollis shows some site fidelity. In Ontario, some breeding sites are regularly occupied, whereas most others may not be used for more than a few years at best.
Population sizes and trends
In British Columbia, the latest population estimate for I. v. auricollis is 152 pairs. There is some suggestion that the population there has declined from historic levels. In Saskatchewan and Alberta, this subspecies expanded its range substantially northward during the 20th century. The Prairie population has been relatively stable since the 1980s, though further increases may have occurred in Saskatchewan. In Alberta, the population is estimated at 900–1 000 pairs. There are an estimated 530 pairs in Saskatchewan. Overall, the population of I. v. auricollis in Canada is estimated at between 1582 and 1682 pairs. In the west, populations in the adjacent U.S. appear to be relatively stable.
For the I. v. virens subspecies, there are fewer than 42 pairs in Ontario. Until very recently, the provincial stronghold was at Point Pelee National Park and Pelee Island, but this is no longer the case. The Ontario population has declined by about 33% over 10 years. The I. v. virens subspecies is showing long-term significant declines in all states adjacent to Ontario, coupled with a range retraction over most of the entire northeast. Thus, the potential for a future rescue effect for the Ontario population is currently low and diminishing.
Threats and limiting factors
In British Columbia, the most important threats to the Southern Mountain I. v. auricollis population are habitat loss from urban and agricultural land uses (coupled with proposed hydro-electric dams that would destroy riparian breeding habitat), road maintenance and/or construction, predation by introduced predators, brood parasitism by cowbirds, pesticide use, and collisions with vehicles and structures. Although the Prairie population of I. v. auricollis in Saskatchewan has increased because of heightened natural succession in riparian areas, some habitat has been lost as a result of reservoir construction. In Alberta, heavy levels of livestock grazing and damming of rivers may affect some sites. For the Ontario population of the virens subspecies, the greatest threats are loss of suitable habitat from land conversion (agriculture/urban) and changes in habitat suitability as a result of natural succession.
Protection, status, and ranks
In Canada, the Yellow-breasted Chat and its nest and eggs are protected under the Migratory Birds Convention Act. In North America, the species is considered secure due to its widespread distribution and relatively stable population overall. The Southern Mountain population in British Columbia is currently afforded protection under the Species at Risk Act (SARA) as an Endangered species. The Prairie population in Alberta and Saskatchewan is considered Not at Risk. In the western United States bordering Canada, the chat is ranked as ‘vulnerable’ in Washington, and ‘secure’ in Idaho and Montana. In Ontario, the virens subspecies is currently designated under SARA as Special Concern. This subspecies is declining strongly across most of its northeastern breeding range, including all states bordering Ontario.
Scientific name
Draba yukonensis
Taxon
Vascular plants
COSEWIC status
Endangered
Canadian range
Yukon
Reason for designation
This small herbaceous mustard is limited globally to one meadow complex in southwestern Yukon; it is found nowhere else on Earth. The meadow complex is under threat from industrial activities, nearby human habitation, invasive species, and trampling by humans and forest encroachment. Human use of the meadows is projected to increase, and encroachment by woody species due to natural succession is causing suitable habitat to decline.
Wildlife species description and significance
Yukon Draba or Yukon Whitlow-grass (Draba yukonensis) is a small herb in the mustard family with untoothed leaves covered with distinctive stiff unforked hairs. Individual plants have a small taproot, one or more rosettes of leaves which lie on the soil, and one or more flower-bearing stems. The flowers are small, white, and have four petals. Other Draba species in the area, including Hoary Draba, are easily differentiated from Draba yukonensis. Draba yukonensis is a Canadian endemic with extremely limited distribution on unusual sandy landforms.
Distribution
Draba yukonensis has been found in only three meadows in a single meadow complex in the Dezadeash River valley in southwestern Yukon, despite numerous searches elsewhere. This locality is within the traditional territory of the Champagne and Aishihik First Nations in an area covering less than 36 hectares.
Canadian distribution of Yukon Draba in the context of the southwest corner of Yukon Territory.
Source: November 2011 COSEWIC Status Report.
Habitat
Draba yukonensis grows on almost flat, well-drained meadows, and is often most dense on the tops of low ridges, bumps, road berms, and Arctic Ground Squirrel mounds. These meadows fall within the rain-shadow of the St. Elias Mountains and are subject to windy conditions, cold winter temperatures, and only modest amounts of snow and rain. The meadows are on ancient sandy beaches and spits formed by Neoglacial Lake Alsek that was formed by a surging glacier that blocked the Alsek River. The lake is thought to have drained around 1852, leaving behind only a few isolated sandy landforms that still remain free of trees and shrubs. Several similar flooding and draining events in recent millennia are thought to have ensured the continued existence of habitat suitable for Draba yukonensis.
Biology
Most aspects of the biology of Draba yukonensis are uncertain, though much can be inferred from its habitat and from related species. Draba yukonensis appears to be a biennial species that can occasionally survive for more than two years. It also appears to be tolerant of dry conditions and direct sun, but intolerant of warmer conditions of south-facing exposures. The ability of Draba yukonensis to disperse via seeds is likely quite limited because it lacks any obvious adaptations promoting long-distance seed dispersal. Damage from small mammal and insect herbivory has been observed.
Population sizes and trends
There is only one known population of Draba yukonensis at the type locality and it is divided unevenly among three adjacent meadows. While these meadows are surrounded by a small number of similar meadows, dispersal to them has not been detected. Limitations in dispersal and habitat availability make the establishment of new sites unlikely.
The population size is subject to extreme fluctuations and may oscillate on a two-year cycle, with even years tending to have more individuals than odd years. Only 109 individuals were counted in 2009, while 5 358 were counted in 2010 in a subset of the inhabited meadows. The total 2010 population was estimated to be between 32 500 and 88 200 individuals. Better information on population size and trends is needed.
Threats and limiting factors
Several risks threaten this population, including expanding roads to access mineral claims, increased traffic through the meadows for mining, logging or recreation, gravel extraction, and the potential expansion of an adjacent subdivision. Invasive plant species well adapted to the meadows occupied by Draba yukonensis are expanding rapidly in Yukon, and may pose an additional threat. The rarity of suitable habitat within the range of natural dispersal, the restricted range, and extreme population fluctuations are serious limiting factors.
Protection, status, and ranks
Draba yukonensis has no legal protection in Canada. The global, national, and territorial NatureServe ranks are “Critically Imperiled” (G1, N1 and S1 respectively). Though its entire occupied habitat is in the Kluane Wildlife Sanctuary, it is not protected from most human land uses. A small portion of potential habitat is protected in Kluane National Park, but no plants have yet been found in the park despite repeated searches.
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