What are Species at Risk?

A "species at risk" is any naturally-occurring plant or animal in danger of extinction or of disappearing from the area. Once they have been classified as "at risk", they are added to the Species at Risk in Ontario (SARO) List.

Why Some Species are at Risk

Through a long history of evolution, each species has become adapted to fit into a particular ecological niche. When a species becomes at risk of disappearing from Canada, there are many possible causes, including habitat loss and degradation, genetic and reproductive isolation, suppression of natural events, environmental contamination, over harvesting, climate change, disease and invasive species.

Reasons for species to be at risk can be as unique and complex as the individual species themselves. However, a large proportion of these factors have to do with human influence and interaction. This is why government intervention, through legislative mechanisms such as Species at Risk Act (SARA), is necessary to ensure that ecological integrity and biological diversity are protected for generations to come. More at Environment Canada.

Species at Risk on the Rice Lake Plains

Note: click thumbnails for larger versions

Eastern Hog-nosed Snake (Heterodon platirhinos) is sometimes mistaken for a cobra because when it is threatened it rears back and flattens its neck out. It may strike out if harassed but rarely bites, and it is non-venomous. It gets its common name from long scales on its nose which give it an upturned snout. Old individuals can be one metre long and their bodies are thick. They prefer sandy, well-drained habitats such as beaches and dry woods because this is where they lay their eggs in burrows and where they hibernate. But they must have access to wet areas such as swamps to hunt frogs, toads and lizards.

Photo by Ken Towle

Threats: The species is at the northern limits of its range in Ontario and was likely never common here. Historic declines were probably due to loss of habitat from development and farming, and persecution by people. These factors continue as threats today and slow the recovery of the species in Ontario. More at the ROM.

Eastern Ribbonsnake (Thamnophis sauritus) is a slim snake with three bright yellow, longitudinal stripes running down its sides, contrasting sharply with the dorsal background colour of chocolate brown or black. Adults can grow to about 70 cm long, and females typically grow larger than males. An adult female gives birth to 5-12 live young in late summer. The baby snakes are independent and begin hunting for insect prey almost immediately. The Eastern Ribbon Snake is usually found close to water, especially in marshes where it hunts for frogs and small fish. At the onset of cold weather, individuals congregate in burrows or rock crevices to hibernate together in what is termed a "hibernaculum."

Photo by Ken Towle
Threats: The Eastern Ribbon Snake is at the northern limit for the species and may never have been common or widespread here. It is likely that the reduction of wetland habitat through urban and agricultural development resulted in a decrease in abundance in Ontario. More at the ROM

Milksnake (Lampropelitis triangulum) is a beautifully marked snake that can grow to a length of one meter or more. Dorsal blotches are usually red with black borders, but coloration is quite variable and blotches may be brown or even green. It is the only snake in Ontario that is reddish. This species is not venomous and captures small mammals, especially mice, and subdues them by constriction. It lives in a wide range of habitats, especially old fields and farm buildings where rodents are common. It is more likely to be encountered at night when it is hunting as it usually remains hidden by day. If surprised or threatened, it will take an aggressive posture: It raises its head in the air, vibrates its tail and may attempt to bite. It has sometimes been mistaken for a rattlesnake, as the vibrating tail can make a buzzing sound in dry leaves.

Threats: Historically, human persecution has been a threat. Because it is often around farm buildings, it does get killed by vehicles. Its aggressive behavior and proclivity to inhabit buildings makes it more prone to being killed by humans.

Red-headed Woodpecker (Melanerpes erythrocephalus) has a vivid red head, neck and breast which makes it instantly recognizable. It is a medium-size bird (20cm) that lives in open woodland and woodland edges, especially in oak savannas and riparian forest, which can often be found in parks, golf courses and cemeteries. These habitats contain a higher density of dead trees, which they commonly use for nesting and perching.

It is an omnivorous species, feeding on insects in the summer and nuts in the winter. The Red-Headed Woodpecker lives in southern Ontario where it is widespread but rare.

Photo by Henry McLin
Threats: The population has declined significantly due to habitat loss which can be attributed to forestry and agricultural practices. Its loss is also due to competition for nest sites from the European Starling.
More at the ROM

Common Nighthawk (Chordeiles minor) is a medium-sized bird, 21 - 25 centimetres long, with long, narrow, pointed wings and a long tail that is slightly notched. Its head and eyes are large for its size, its plumage is dark brown with black, white and buff specks, allowing it to blend in with roost sites which include gravel beaches and rocky outcrops or burned woodlands.

Their habitat, consists of open areas with little or no ground vegetation such as forest clearings and burned-over areas. They winter in South America.

Photo by Bill Hubick
Threats: Large-scale use of insecticides may be partly responsible due to insects being their main food source. Other threats include habitat degradation resulting from fire suppression, land use changes and an increase in intensive agriculture. More from MNR

Least Bittern (lxobrychus exilis) is the smallest of the North American herons and is distinguished by large chestnut patches on its wings. Males are darker than females. However they are more likely to be heard than seen as it "coos" softly from deep in a cattail marsh. It is found mainly in large, quiet marshes close to the Great Lakes.

Threats: The principal threat to the Least Bittern is the draining of wetlands for conversion to farmland and urban development. As marshes decrease in size and recreation and noise increase, the population declines in the area. More at the ROM

Photo by George Jett

Monarch Butterfly (Danaus plexippus) can be found in Ontario wherever there are milkweed plants for its caterpillars and wildflowers for a nectar source. Monarchs are often found on abandoned farmland and roadsides, but also in city gardens and parks. The eastern North American population migrates to Mexico each fall to overwinter at 12 sites in the central mountains. The location of these wintering sites was only discovered fairly recently, after years of study. Biologists from Toronto glued identification tags to the wings of thousands of Monarchs in the fall so that observers across Central and North America could document the migration pathway.

Photo by Mia Frankl
Threats: Declines in the Ontario populations of Monarchs are due to factors on the wintering grounds and in Ontario. The main causes of decline are logging and disturbance of the overwintering sites in Mexico, and the widespread use of pesticides and herbicides in Ontario.

Karner Blue (Plebejus Melissa samuelis) EXP is a stunningly beautiful butterfly whose upper wing surfaces are the clearest azure blue. Females are a darker, greyish blue. Unfortunately, this butterfly can no longer be found in its former black oak savanna habitat in Ontario, and it is considered extirpated here (i.e., regionally extinct, but continuing to exist elsewhere). Female Karner Blues lay their eggs on or near Wild Lupine (Lupinus perennis) which serves as the food plant of the butterfly larvae. Ants tend the larvae, protecting them from predators such as spiders.

(no larger version)
Threats: Habitat loss is responsible for the decline of the Karner Blue throughout its range. The disappearance of habitat in Ontario can be attributed to plant succession which creates shady conditions unsuitable for the growth of Wild Lupine. More at the ROM

Butternut (Juglans cinerea) is a medium-sized tree that belongs to the Walnut family, and like the other native walnut in Ontario, the Black Walnut, it produces edible nuts in the fall. The roots of Butternut secrete juglone, an allopathic chemical that can kill other plants growing nearby.

Threats: Butternut trees are normally found scattered at low density in forests, and were thus never common in Ontario. Today, the main threat to Butternut is a serious fungal disease called Butternut Canker, which was first found in Ontario trees in 1991, but has been in North America for about 50 years.

Butternut tree & nuts
The fungus can kill a tree within a few years of infection. It enters through cracks or wounds in the bark and multiplies rapidly, making sunken cankers that expand and girdle the branch or trunk, killing everything above the canker. In Ontario, surveys in eastern Ontario show that most trees are infected, and perhaps one-third have been killed. More from the ROM

Cylindrical Blazing Star (liatris cylindracea) this native perennial is also known as slender blazing star, Ontario blazing star, barrelhead gayfeather and few-headed blazing-star. It is a member of the Aster family.

The flowers are purple to pink on a short spike at the top of the stem. Each compound flower consists of about 15-25 tubular flowers that are crowded together into a head that is about 2-3 cm across; each flower has 5 small lobes that curl outward. It has no floral scent. Flowers between July – September. It has basal leaves in a rosette and the leaf can be up to 40cm long, becoming smaller and fewer towards the top of the stem. Its height can be as much as 1m but is generally shorter. Habitat: Dry woodlands, prairies, fields and meadows.

Threats: Habitat loss, the use of pesticides and increased agriculture are responsible for the rarity of this plant.

Prairie Buttercup (Ranunculus rhomboideus)
Description: Plants are less than 1 ft. tall with long soft hairs on the leaves and stems. The long-stalked basal leaves are up to 2" long and about as wide, with coarse, rounded teeth or even small lobes. The stem leaves are usually stalkless and divided into 3 narrow lobes. There are usually several individually stalked flowers per plant. Each flower is about 3/4" wide with 5 small hairy sepals and 5 yellow petals surrounding many yellow stamens. It blooms from midspring - early summer.

Habitat: Restricted to dry prairies and dry open woodlands, usually in areas of sparse, low vegetation; found in the tallgrass region of North America.

Photo by Amanda Newell
Threats: This prairie species requires open spaces to survive. It is under threat from roadside rights-of-way and trampling and from the use of insecticides. Its growth may be encouraged by the use of prescribed burning.

Grooved Yellow Flax (Linum sulcatum)
Grooved yellow flax is an erect annual herb that grows up to 2½ feet (75 cm) tall. The common name refers to its grooved stems which are purplish near the base. The leaves grow alternately along the stem. They are linear to oblong, have smooth margins, and attach directly to the stem without a petiole. There are two distinctive blackish glands on the stem near the base of each leaf. The flowers are yellow, have 5 smooth petals, and are roughly ½ inch (12 cm) wide. They are held in loose clusters near the top of the stem and bloom from May to September.

Habitat: Grooved Yellow Flax can be found growing in scattered sites on sandy barrens.

Threats: This plant is considered to be a species of special concern, based on the relatively few occurrences that have been confirmed and the very specialized habitat. It has been assigned a rarity status of Endangered. Grooved yellow flax populations are threatened by habitat loss and succession. Over time, the open nature of the habitats required by this species may be lost due to encroachment by woody and invasive species. Other potential hazards include trampling, incompatible land management, and habitat fragmentation, which limits seed dispersal.

Arrow-leaved violet (Viola sagittata)
The shape of the leaf is a distinguishing feature for this violet. They are oval to triangular in outline, rather than heart-shaped. The hairy leaves of this specimen mark it as Viola sagittata var. ovata. Its habitat is dry woods, clearings and rocky areas. It grows to a height of 4-6 inches with a flower size of 3/4 inch. The flowers are purple and the plant flowers from April to June.

Threats: The principal threats to the Arrow-leaved violet include changes in water quality due to sedimentation, trampling and over-shading or competition from aggressive native and exotic invasive species such as Buckthorn.

Photo by Connecticut Botanical Society






A species that no longer exists in the wild in Ontario but still occurs elsewhere.



A species facing imminent extinction or extirpation in Ontario which is a candidate for regulation under Ontario's ESA.



A species that is at risk of becoming endangered in Ontario if limiting factors are not reversed.


Special Concern
(formerly Vulnerable)

A species with characteristics that make it sensitive to human activities or natural events.

Link to COSEWIC - Committee on the Status of Endangered Wildlife in Canada

Link to COSSARO - Committee on the Status of Species at Risk in Ontario

Information in this section of the Rice Lake Plains Website has been taken from the Ministry of Natural Resources Species at Risk pages. There are links to the MNR website to allow you to find detailed information about each of the species listed.


Here's the Tallgrass Prairie "Species at Risk" story…

Thanks to funding from Environment Canada's Habitat Stewardship Program for Species at Risk and the Ontario Ministry of Natural Resources' Species at Risk Stewardship Fund the Nature Conservancy of Canada with support from the Rice Lake Plains Joint Initiative has worked to improve awareness of species at risk in the nationally threatened tallgrass prairie ecosystem. Efforts have been concentrated on vulnerable snake and bird species throughout the Rice Lake Plains in Northumberland County. Summer 2009 marked the third year for such work.

The first two years brought a wealth of information regarding the occurrence of the nationally and provincially threatened Eastern Hog-nosed snake in the area. More than a dozen new sightings were recorded. The Eastern Milksnake is a species of special concern provincially and federally and was also featured by informing landowners about its decline and reasons it is at risk. Field staff visited with landowners, attended conservation events, presented programs to school groups and mailed post cards to selected landowners with the ultimate goal of documenting snake sightings and helping to protect these species at risk.

This past summer and early fall three birds species were added as focus species in hopes of increasing awareness and gathering sighting data about grassland birds. The Common Nighthawk, Whip-poor-will and Red-headed Woodpecker are known to utilize prairie, savanna and edge habitat where insects are abundant. Unfortunately due to habitat loss, changing land use activities and the spread of invasive species much of their critical grassland habitat has been lost.

NCC and the Rice Lake Plains Joint Initiative continue to seek information about each of these species at risk. Landowners who see these species are encouraged to contact NCC at (705) 761-6466 or by email at todd.farrell@natureconservancy.ca. Photographs of these species are most helpful for record keeping purposes as are details of their location and behavior.
(Mark Stabb, Nature Conservancy of Canada)

Here's what we're doing for Species at Risk…

On a recent sunny and cold winter's day more than 70 participants took part in a bird conservation workshop hosted by the Nature Conservancy of Canada (NCC) and the Rice Lake Plains Joint Initiative. This free event was held on Saturday February 6th at the Alderville Black Oak Savanna Ecology Centre. Interested landowners from Northumberland and surrounding counties learned about bird species at risk throughout the Rice Lake Plains. Willow Beach Field Naturalist Executive member Ben Walters who is also a Ph.D. candidate at Trent University, Peterborough, provided insight to the changing bird populations of the area. He combed hundreds of ornithological records dating back to the 1820s to produce an in-depth look at Birds of the Rice Lake Plains.

Barbara Frei also a Ph.D. candidate, from McGill University in Montreal, spoke about "Biodiversity in your Backyard - The Story of Red-headed Woodpeckers in Central Ontario". Ms. Frei will begin three years of field work this spring throughout Northumberland, Peterborough and Hastings Counties looking for the only woodpecker with an all-red head. She is asking landowners to assist her with her research by contacting her with Red-headed Woodpecker sightings at barbara.frei@mail.mcgill.ca.

The NCC together with the Rice Lake Plains Joint Initiative, a seven-member organization, are working towards the restoration and protection of sustainable tallgrass prairie and oak savanna habitat. They are using a co-operative approach to conservation science, land stewardship, public outreach, and legal protection of land.

The workshop was partially funded by the Ontario Ministry of Natural Resources Species at Risk Stewardship Fund and Environment Canada's Habitat Stewardship Program. NCC and the Rice Lake Plains Joint Initiative continue to seek information about many bird species at risk such as the Common Nighthawk, Whip-poor-will and Red-headed Woodpecker as well as snake species like the Milksnake and Eastern Hog-nosed snake. Landowners who see these species are encouraged to contact NCC at (905) 862-2642 or by email at todd.farrell@natureconservancy.ca. Photographs of these species are most helpful for record keeping purposes as are details of their location and behavior.
(Kristina Hubert - Nature Conservancy of Canada)

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