Ontario Nature’s Biodiversity Watch List
Nearly 200 species of plants and animals in Ontario are classified as at risk meaning that they are in danger of becoming extinct either locally or globally. In recognition of the International Year of Biodiversity, Ontario Nature has identified 10 species that highlight the loss of biodiversity and raise awareness about species at risk in Ontario.
Eastern massasauga rattlesnake (Threatened)
Urban sprawl coupled with the conversion of natural areas for agriculture throughout much of southwestern Ontario have caused a massive decline in habitat suitable for these snakes. Road mortality has also contributed to this species' decline, and is probably the largest single threat to the massasauga rattlesnake in areas that are classified as protected. Human persecution due to misconceptions about the danger of the snake has also been a significant contributing factor to its decline, especially in heavily populated areas. Ontario’s remaining populations are vulnerable to ongoing development pressure and are at risk of increasing declines as a result.
Easter massasauga CREDIT: Joe Crowley
Fun fact:This snake "rattles" by rapidly vibrating its tail, causing the interlocking rattle segments to hit each other. The massasauga's rattle is made of the same substance as our fingernails, and is so fragile it can break off. Newborns only have one "button," and add a new segment to their rattle each time they shed their skin, which is typically one to three times a year.
Woodland caribou (Threatened)
This iconic northern species, featured on the Canadian quarter, has lost 50 percent of its range in Ontario. Forestry, hydro, mining and other industrial activities are the primary threats to the woodland caribou. An inhabitant of mature forests, this majestic animal needs large, unbroken landscapes so it can avoid predators. The provincial government is currently working on policies and regulations that will determine where industrial projects can take place without disturbing caribou habitat. If numbers continue to drop as quickly as they have over the past years, the species could disappear by the end of the century.
Woodland caribou CREDIT: Paul Tessier Fun fact: When female caribou are about to have their young, the animals seek out the isolation and protection of bogs or islands at densities as low as one female per 20 square kilometres.
Fowler’s toad (Threatened)
This once common amphibian is now found only along the Lake Erie shoreline in beach habitat, an intensively developed area and tourist attraction, resulting in habitat damage and loss. Shoreline development and pesticide use have taken a toll on tadpoles and adults. Worldwide, more than one-third of amphibian species are listed as species at risk and many more are in decline. The plight of the Fowler’s toad illustrates the serious danger that all of Ontario’s amphibians are facing.
Redside dace (Endangered)
Much of the habitat for this species is located in the Golden Horseshoe region of Toronto—an area of rapid population growth and urban expansion. Despite increased protection to parts of the dace’s habitat with the passing of the Greenbelt Plan, this small, colourful fish is still threatened by development. The Province will soon pass regulations to protect the redside dace and it is crucial that clear thresholds are established so that the species can survive if development continues to occur within or near important habitat.
Redside dace CREDIT: Royal Ontario MuseumFun fact: Despite its diminutive size, the redside dace leaps out of the water to feed on low flying insects.
Blanding’s turtle (Threatened)
Isolated populations of the Blanding’s turtle are scattered throughout southern Ontario to about North Bay, Sudbury and Manitoulin Island. An unusually large and healthy population of these turtles inhabits a wetland outside of Ottawa that, unfortunately, is in the path of a proposed extension of the Terry Fox Drive. Construction of the road will probably destroy this group of rare turtles. The impact of this loss on overall population numbers could be devastating.
Blanding's turtle CREDIT: Joe CrowleyFun fact: Blanding's turtles reach sexual maturity around the age of 15, and can live for more than seven decades.
The Detroit River International Corridor (DRIC) project, which entails the construction of buildings and roads along the Canada-U.S. border, will damage the single largest community of colicroot in Ontario. Mitigation measures proposed for the DRIC by the Ministry of Transportation have never been successfully tested, yet are supported by the Ministry of Natural Resources. As a result, the survival of this rare plant is extremely precarious.
ColicrootFun fact: Herbalists use the rhizome of this plant to treat indigestion and rheumatism.
American badger (Endangered)
Less than 200 American badgers remain in Ontario. The badger is one of many species that depend on farmers to maintain good stewardship practices to conserve critical habitat. The Ministry of Natural Resources and groups like Ontario Nature are working together to find ways for rural landowners and farmers to use their land productively without forfeiting the protection of an endangered species.
American badger CREDIT: John Pitcher Fun fact: The American badger has an unusual reproductive cycle. Even though mating occurs in June, the fertilized egg does not attach itself to the uterus until about six months later. This delayed implantation ensures that the cubs are born in the spring when the weather is warmer and more food is available.
Rapids clubtail (Endangered)
In 2009, the rapids clubtail dragonfly was awarded the dubious distinction of becoming the first Ontario dragonfly to be listed as endangered. As an aquatic species during its larval stage, this insect is extremely sensitive to the degradation of river corridors largely caused by dams and rising pollution levels. Previously located in only four rivers in southern Ontario, the clubtail is now found only along southern Ontario’s Humber and Mississippi rivers .
Rapids clubtail CREDIT: Steve Collins Fun fact: This brightly coloured dragonfly has blue-green eyes, a yellow-green face, a striped body (brown-black and yellow-green) and transparent wings.
Rayed bean (Endangered)
The rayed bean, one of Canada’s smallest freshwater mussels, inhabits clear streams and rivers with sand and gravel bottoms. Once found across southern Ontario, the mussel is now believed to exist only in the Sydenham River and the North Thames River. Pollution and habitat loss from siltation and dams have decimated its numbers.
Rayed bean CREDIT: Todd J. Morris
Fun fact: The rayed bean is a parasite on the gills of fish. The hosts are: rainbow darter, greenside darter, mottled sculpin and largemouth bass.
Canada warbler (Special Concern)
Canada warbler tallies during annual bird counts have dropped by 85 percent in the last four decades, largely due to habitat loss and increasing mortality rates from flying into tall buildings in urban areas during spring and fall migration. Ontario Nature recently launched legal action to help address the loss of birds due to poorly sited buildings in the Greater Toronto Area.
Canada warbler CREDIT: Robert McCaw Fun fact: The Canada warbler is one of the last birds to migrate to Ontario in spring, and one of the first to leave at the end of summer. They are rarely seen but hard to miss when in the open – the birds have bright yellow stomach plumage, and males have a distinctive black “necklace” of feathers under the chin.