Ontario's Carolinian zone is the province's most diverse and most threatened ecological region. Over five hundred species of plants and animals in the region are considered rare.

What Species are Rare?

Rare species are species that occur in small numbers, in a small region or small number of locations. Such species can be prone to become at risk of decline from human impacts or natural events. To define rarity in scientific terms, federal and provincial governments and scientists have developed ways to assess and classify species into more specific categories of rarity and risk.

The federal government working with the provinces, set up the Committee on the Status of Endangered Wildlife in Canada or COSEWIC to assess the status of species at risk. COSEWIC assesses the status of wildlife species using the best available knowledge. There are four steps in the process: 1) determining the eligibility of species; 2) choosing species and assigning priorities; 3) assessing the risk of extinction; and 4) publication of COSEWIC's assessments with scientific rationale.

When a decision is made to assess a species' status, COSEWIC commissions reports on the status of the species. Status reports take up to two years to prepare. The status report will be used by COSEWIC to assign the species to one of seven categories:

1. Extinct
2. Extirpated (species no longer present in the wild in Canada)
3. Endangered
4. Threatened
5. Special concern
6. Species not at risk, and
7. Data deficient.

Under the new federal Species at Risk Act, these designations will have legal force and require certain actions and provide different tools for species protection and restoration.

Ontario's Endangered Species Act provides protection for species designated under the Act and the Provincial Policy Statement also provides some protection for endangered and threatened species. To determine official provincial status. Ontario has a parallel committee called the Committee on Species at Risk in Ontario or COSARO.

The Natural Heritage Information Centre (NHIC), as part of an international system of conservation data centres, also assesses species' status globally, in Canada and in Ontario. The NHIC, working with counterparts across Canada, the U.S. and the world, assigns Global Ranks of 1 to 5 for species and Provincial Ranks of 1 to 5 based on range, population size and other factors. The Natural Heritage Information Centre also assesses the status of ecosystem or vegetation communities.

Rare Species and Ecosystems in the Carolinian Zone

Over 125 species in Carolinian Canada are considered vulnerable, species of special concern, threatened or endangered by either the federal or provincial government (COSEWIC or COSARO). Over 400 other species in Carolinian Canada are considered rare by the Natural Heritage Information Centre.

The Carolinian zone habitats and ecosystems include forests, tallgrass prairies and savannas, wetlands, streams, shorelines and other aquatic habitats. Fifty-eight of these ecosystem types is considered rare. Each of these ecosystems have a distinctive set of species.