Red-spotted newt © Joe Crowley
In some newt species, including the red-spotted newt, the aquatic larvae go through a terrestrial stage before later maturing into aquatic adults. Newts in the terrestrial stage are called efts. Many species of newts do not go through the terrestrial eft stage, but rather transform from larvae directly into aquatic adults.
Characteristics
Red-spotted newt (Notophthalmus viridescens viridescens) adults and efts have two rows of dark-ringed, orange-red spots. Efts can grow to over eight centimetres in length, while the adult salamander, which is aquatic, can reach 14 centimetres, including the tail. Efts have bright orange or brownish bodies and are seen more often than the greenish yellow aquatic adults. The skin of efts is rough, rather than smooth like that of other salamanders. When they emerge from the egg, the larvae have a gold tinge and a black stripe through the eye.
Red-spotted newt © Noah Cole
Similar Species
The red-spotted newt is the only species of newt in central and southern Ontario. The central newt, a subspecies found in Ontario west of Lake Superior, has a darker back and fewer spots.
Red-spotted newt © Joe Crowley
Habitat
Adult newts are generally found in slow-moving water in a variety of ponds and lakes, and along quiet stretches of streams and swamps. The terrestrial eft is found in the surrounding damp woodlands, usually under logs or bark on the forest floor, and seldom enters water. Both adults and efts spend the winter on land, adults beneath logs or rocks and efts in leaf litter on the forest floor. In some populations, adults remain in the water over the winter.
View an interactive map of the known ranges of red-spotted newts in Ontario.
Biology
Red-spotted newts breed in spring. Newts are known for their elaborate courtship displays. Females lay 80 to 450 eggs, individually, on submerged vegetation. The eggs hatch in two to four weeks. By the end of the summer, the larvae will transform into efts and move to land. When the efts reach maturity after a total of two to seven years, they transform into aquatic adults and return to the water. Like salmon, most newts return to breed in the water where they were born. Migrations generally coincide with heavy rainfall.
Efts are carnivorous and feed on a variety of insects. Adult newts may remain active year-round and feed on many aquatic organisms, including insects, small crustaceans and even other amphibian eggs and larvae.
Newts may live for more than 15 years. These animals contain toxins in their skin that are lethal to most predators, except gartersnakes. When a predator threatens a newt, it assumes a posture that displays the bright colour of its underside, which presumably warns the predator that its prey is toxic.
Other names: eastern newt
Red-spotted newt eft © Scott Gillingwater
Threats and Trends
Amphibians absorb water, oxygen and nutrients through their skin. Newts, in particular, spend most of their lives in water and, as such, need high-quality water to survive. Heavy siltation, agricultural runoff and pollutants reduce habitat quality. Many newts are killed on roads every spring and fall during migration to breeding ponds. Reporting observations of road-killed newts to the Herps of Ontario iNaturalist project can help researchers identify these critical migration routes.
Red-spotted newt © Noah Cole
Current Status and Protection
Neither the Committee on the Status of Species at Risk in Ontario nor the Committee on the Status of Endangered Wildlife in Canada has assessed the status of the eastern newt. The species receives no protection under the Ontario Fish and Wildlife Conservation Act.
The International Union for Conservation of Nature has not yet assessed the global status of the red-spotted newt, but lists the global status of the eastern newt (of which the red-spotted newt is a subspecies) as Least Concern. The speciess status was confirmed in December 2020.
Learn more about reptile and amphibian conservation and what you can do to help these species on our Reptile and Amphibian Stewardship page.
Red-spotted newt © Noah Cole
What You Can Do
- Report a sighting
- Get involved in reptile and amphibian conservation on your property, on the road and in your community
- Donate to support reptile and amphibian conservation
- Watch for reptiles and amphibians on the road
- Don’t release pet reptiles and amphibians into the wild
- Read more about the red-spotted newt in the Ontario Reptile and Amphibians Atlas publication.
Red-spotted newt © Joe Crowley
Powered by flickr embed.