Red-spotted Newt

Notophthalmus viridescens viridescens

Family: Salamandridae

The Red-spotted Newt is a sub-species of the Eastern Newt (Notophthalmus viridescens).

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Description

Red-spotted Newts are green, olive or brown with dark flecks and two rows of red spots, and the belly is yellow with black spots or flecks. This species lacks the costal grooves that are present on most other Canadian salamander species and the tail is laterally compressed with a prominent ridge. Red efts (see biology) are generally bright red or orange with a row of black-bordered red to orange spots on each side. Aquatic larvae have feathery gills behind the head, legs (both front and back) and a tail fin. The larvae are grey to brown, often with two rows of yellow spots. Red-spotted Newts can grow up to 14 cm in total length.

Similar Species

Red-spotted Newts may be confused with the other sub-species of newt found in Ontario, the Central Newt, but the ranges of the two sub-species do not overlap. Central Newts are smaller than Red-spotted Newts and usually lack the red spots on the back. Unlike other Canadian salamanders, newts lack costal grooves and they have rough textured skin. The laterally compressed tail also distinguishes them from many Canadian Salamanders.

Distribution

In Canada, Red-spotted Newts range from central Ontario east to Nova Scotia and PEI. This subspecies also occurs throughout the northeastern United States west to Michigan and south to Mississippi, Alabama and Georgia.

Habitat

Aquatic adults and larvae can be found in wetlands, ponds, pools, sloughs, slow streams and other permanent shallow aquatic habitats. These habitats typically have abundant aquatic vegetation and are often in forested areas. Terrestrial red efts are generally found in forests, although they can also be located in old fields, back yards near natural areas and wet meadows. In large, permanent bodies of water, newts often spend the winter in the water and may remain active through much of the winter. Individuals that inhabit shallow or seasonal wetlands hibernate in terrestrial habitats in underground cavities or under cover such as rotting logs.

Biology

Red-spotted Newts breed in the spring. Females lay 200–375 eggs singly or in small clumps, which they attach to aquatic vegetation or submerged leaves. The eggs typically hatch in two to four weeks depending on the temperature. In late summery or early fall, aquatic larvae typically develop into terrestrial juveniles (red efts), but some individuals may also develop directly into aquatic adults. The juvenile red eft stage lasts for two to seven years before individuals return to aquatic habitats and transforming into aquatic adults. This terrestrial stage is a unique adaptation that allows an otherwise aquatic species to disperse over land to locate new aquatic habitats. The terrestrial eft stage also enables populations to persist through periods of drought when aquatic habitats become limited. Red-spotted Newts can live up to 15 years in the wild. Adult newts prey on a variety of aquatic invertebrates, such as insects and microcrustaceans, while terrestrial newts forage for invertebrates on the forest floor.

Threats

The extensive conversion of wetlands to agricultural and urban land uses has destroyed and fragmented much of this species’ habitat throughout the southern portion of its range in Canada, and wetland loss continues to threaten populations. However, this species is relatively abundant throughout its Canadian range and threats to most populations are minimal. Pollution, such as herbicides, agricultural effluent and road salt can be detrimental to newts since toxins are easily absorbed though their skin. Climate change and introduced pathogens pose potentially serious future threats to Canadian salamander

Additional Information About This Species In Canada