OTTAWA, November 29, 2010 /Canada NewsWire/ - Two birds considered extremely rare to Canada were both re-assessed as Endangered despite recovery initiatives. The White-headed Woodpecker and Sage Thrasher are just two of the 52 Canadian wildlife species that were assessed for risk of extinction or extirpation by COSEWIC (Committee on the Status of Endangered Wildlife in Canada) when it met in Ottawa, November 22-26, 2010. Of the thirty-two species that were re-assessed after 10 years, as required by the Species at Risk Act, only four were found to be less at risk.
Fewer than 100 of the spectacular White-headed Woodpecker nest in southeastern British Columbia. This bird depends on mature Ponderosa Pine forests which continue to decline due to severe fires and Mountain Pine Beetle infestations. Even rarer is the Sage Thrasher. Although never common in BC, Alberta or Saskatchewan, the total population of this small brown songbird in Canada ranges from only seven to 36 individuals. Loss of sagebrush habitat, used for nesting, is undoubtedly responsible for declines of this bird in Canada.
Although increased efforts to survey rare plants in Ontario resulted in larger population estimates for the Dwarf Lake Iris; habitat degradation still plagues species with extremely limited ranges in the Great Lakes region of Ontario and Québec. Two small orchids, the Nodding Pogonia which was assessed as Endangered and the Purple Twayblade, a Threatened species, are highly vulnerable to ongoing habitat alterations associated with invasive plants, introduced earthworms, and land development. The Endangered White Prairie Gentian, a large showy perennial known for its traditional medicinal uses, now exists as only a single small population in southern Ontario where its savannah habitat is protected from degradation by the Walpole Island First Nation.
Two Iconic Canadian Fishes at Risk
The Atlantic Salmon, one of the world's most commonly farmed marine fishes, has suffered declines in the wild, particularly in southern parts of its Canadian range. Regardless of ongoing activities to rebuild stocks, one population in southern Newfoundland was designated as Threatened, and five populations in the Bay of Fundy, outer coast of Nova Scotia and Anticosti Island were assessed as Endangered. The unique Lake Ontario population was considered Extinct. To the north, the situation is not as dire. Populations in the Gulf of St. Lawrence were assessed as Special Concern and three of the most northern populations in Canada were considered Not at Risk; relatively pristine rivers and improved fisheries management likely explain the stable to increasing abundance of these northern populations.
Aboriginal Traditional Knowledge contributed significantly to understanding the biology and threats for Dolly Varden, a trout-like fish of great significance to the people of the western Arctic. Despite the relative health of these populations, climate change poses a significant risk. This factor, in addition to the sensitivity of this fish to habitat impacts and fishing pressure, resulted in a designation of Special Concern.
Zebra Mussel Now Threatens Species West of the 100th Meridian
The Rocky Mountain Ridged Mussel is a large conspicuous freshwater mussel residing in the Okanagan Lake basin. Its restricted range coupled with the threat of the invasive Zebra Mussel and burgeoning lakeshore development elevated the risks to this species which led to an assessment of Endangered from a previous assessment of Special Concern.
Some Cause for Optimism.
The case of the Barndoor Skate does give cause for some optimism. This large, distinctive marine fish experienced severe population declines and was virtually undetectable in Canadian waters for two decades. Reduced fishing pressure has contributed to significant increases in the Barndoor Skate since the 1990s. While this skate has not fully recovered to historical levels, the fish was assessed as Not at Risk.
COSEWIC assesses the status of wild species, subspecies, varieties, or other important units of biological diversity, considered to be at risk in Canada. To do so, COSEWIC uses scientific, Aboriginal traditional and community knowledge provided by experts from governments, academia and other organizations. Summaries of assessments are currently available to the public on the COSEWIC website ( www.cosewic.gc.ca) and will be submitted to the Federal Minister of the Environment in late summer 2011 for listing consideration under the Species at Risk Act (SARA). At that time, the full status reports and status appraisal summaries will be publicly available on the Species at Risk Public Registry ( www.sararegistry.gc.ca).
There are now 617 wildlife species in various COSEWIC risk categories, including 270 Endangered, 153 Threatened, 172 Special Concern, and 22 Extirpated (i.e. no longer found in the wild in Canada). In addition to these wildlife species that are in COSEWIC risk categories, there are 14 wildlife species that are Extinct.
COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Fisheries and Oceans Canada, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three Non-government Science Members, and the Co-chairs of the Species Specialist and the Aboriginal Traditional Knowledge Subcommittees.