Prepared by the Ontario Ministry of Natural Resources. Adoption of Recovery Strategy for the Pitcher’s Thistle (Cirsium pitcheri) in Canada (Parks Canada Agency 2011).

The Endangered Species Act, 2007 (ESA) requires the Minister of Natural Resources to ensure recovery strategies are prepared for all species listed as endangered or threatened on the Species at Risk in Ontario (SARO) List. Under the ESA, a recovery strategy may incorporate all or part of an existing plan that relates to the species.

The Pitcher’s Thistle (Cirsium pitcheri) is listed as threatened on the SARO List. The species is also listed as endangered under the federal Species at Risk Act (SARA). Parks Canada Agency prepared the Recovery Strategy for the Pitcher’s Thistle in Canada in March 2011 to meet its requirements under the SARA. This recovery strategy is hereby adopted under the ESA. With the additions indicated below, the enclosed strategy meets all of the content requirements outlined in the ESA.

The Critical Habitat section of the federal recovery strategy provides an identification of critical habitat (as defined under the SARA). Identification of critical habitat is not a component of a recovery strategy prepared under the ESA. However, it is recommended that the areas of critical habitat identified in the federal recovery strategy be considered when developing a habitat regulation under the ESA.

Executive summary

Prepared by Parks Canada Agency

Pitcher’s Thistle is a whitish-green perennial plant with leaves that are finely divided into narrow segments and spineless except at the tips. The plants live as a ring of basal leaves (a "rosette") for several years before forming an upright flowering stalk and thistle head of pale, pinkish-white flowers. After flowering and setting seed, the plants die. In Canada Pitcher’s Thistle is only found on dunes and beach ridges on the shores of Lake Huron and Lake Superior. Optimal habitat is open, dry, loose sand with little other vegetation. The habitat is dynamic due to sand movement caused by wind, water, and ice actions. There is a balance between the processes that keep sand open and loose, and succession, the natural process that causes a gradual increase in vegetation.

Pitcher’s Thistle is listed as Endangered on Schedule 1 of the federal Species at Risk Act (SARA). In Ontario species is listed as Endangered on the Species at Risk in Ontario list under the Endangered Species Act, 2007 (ESA 2007). The global range of Pitcher’s Thistle is completely restricted to the shores of Lakes Huron, Michigan and Superior, occurring in four states in the United States and Ontario.

There are 30 extant populations in Canada, all in Ontario; three are on southern Lake Huron, two are on Lake Superior, and the remaining 25 are in Manitoulin Region on Lake Huron. Pitcher’s Thistle has been extirpated from some historic sites on southern Lake Huron. Since 2001 several previously unknown populations of Pitcher’s Thistle were discovered in the Manitoulin Region. At the same time, there have been large increases in numbers of individuals at many known populations in that region. Based on 2008 monitoring data the current total Canadian population is around 55,000 individuals.

Threats to Pitcher’s Thistle are off-road vehicles, browsing; trampling; succession, construction of human structures on beaches, erosion and blow- outs, and competition with invasive species.

The current state of Pitcher’s Thistle populations varies considerably by region. Populations at Pukaskwa National Park are small, with one population appearing healthy and self sustaining, one declining and one population recently extirpated, whereas on Lake Huron, the majority of populations show increases or fluctuations. The populations in the southern Lake Huron region are small, but most seem stable. There is almost no threat of extirpation of the listed species within the next 10 years, although there could be serious losses at the edges of the range. Consequently, the following objectives are designed to ensure the survival of the listed species:

Pukaskwa National Park: Maintain the two existing populations (Oiseau Bay and Hattie Cove) at their current locations. Use the existing populations to restore Pitcher’s Thistle into suitable habitat at a selected site by 2020. Maintain populations at high enough levels that yearly population sizes show natural fluctuations with declines no greater than 30%.

The Manitoulin Region: Maintain the current extent of occurrence, and the largest population of Pitcher’s Thistle in the region on Great Duck Island.

The Southern Lake Huron Regions: Maintain or increase all the existing populations in Inverhuron, Pinery and Port Franks.

Recovery work will involve protection of existing populations, reductions of threats to habitat, and promoting site stewardship, public education, and policy- oriented approaches. Pitcher’s Thistle populations are under several types of ownership or jurisdiction, and First Nations, municipalities, and private landowners will be important partners in recovery work. Critical habitat is identified in this strategy for populations at Pukaskwa National Park, Pinery and Inverhuron Provincial Parks, Port Franks, and Great Duck Island.

One or more action plans will be completed by 2015.