The white-headed woodpecker is one of Canada's rarest birds. There are an estimated 100 nests in southeastern British Columbia. ((Jared Hobbs/COSEWIC))

The latest report card on Canada's endangered species shows just four of 32 wildlife species assessed are less at risk today than they were 10 years ago.

The barndoor skate, a large marine fish virtually undetectable in Canadian waters for two decades, was upgraded to not-at-risk, said the Committee on the Status of Endangered Wildlife in Canada, a group of government, academic and non-government experts.

In an assessment released Monday, the committee said while the skate has not recovered to historic levels, reduced fishing pressure in its Western Atlantic habitat contributed to significant increases.

On the other hand, two of the country's rarest birds — the white-headed woodpecker and sage thrasher — were both reassessed as endangered, despite recovery efforts, said COSEWIC. 

The committee provides the federal government with updated assessments of wildlife every November and May. It is then up to the minister of the environment to decide whether to accept the recommendations and place the animals and plants under the protection of the federal Species at Risk Act.

The committee's most recent assessment examined 52 species in total, including 32 it was mandated to reassess after a 10-year period. It found fewer than 100 white-headed woodpecker nests in southeastern British Columbia. The bird depends on mature ponderosa pine forests, which continue to decline because of severe fires and mountain pine beetle infestations.

The even rarer sage thrasher was never common in B.C., Alberta or Saskatchewan, but the total population of this small brown songbird now ranges from only seven to 36 individuals, said the committee. It blamed loss of sagebrush habitat, used for nesting, for the bird's decline.

The committee, which used traditional aboriginal knowledge in its assessments, said such knowledge was especially useful in understanding threats to the Dolly Varden, a trout-like fish of great significance to the people of the western Arctic. 

Despite the relative health of these populations, the committee classified it as a species of special concern because climate change and over-fishing pose a significant risk to its northern habitat.

Atlantic salmon declined

Atlantic salmon, one of the world's most commonly farmed marine fishes, has suffered declines in the wild, particularly in southern parts of its range, said the committee. 

Despite attempts 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 of special concern and three of the most northern populations were considered not at risk. Relatively pristine rivers and improved fisheries management likely explain the stable to increasing abundance of these northern populations.

The committee also highlighted the plight of a number of rare plants in Ontario.

Although better surveys showed larger population estimates for the dwarf lake iris, habitat degradation still plagues plants with extremely limited ranges in the Great Lakes region of Ontario and Quebec. For example, the nodding pogonia orchid was assessed as endangered and the purple twayblade orchid, as threatened. The two species are highly vulnerable to invasive plants, introduced earthworms and 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 in Lake St. Clair.