Other names: Pacific Coast Newt, Roughskin Newt, Western Newt
The Rough-skinned Newt is a medium-large, heavy bodied salamander with grainy, dry skin. They can reach a total length of up to 22 cm. They may look “chubby” compared to other salamanders due to the absence of . They have long legs with slightly flat fingers and toes and a laterally compressed tail. The skin is rough with small and is usually solid brown, black or dark-olive with an orange belly. Rough-skinned Newt larvae are brown with a row of light-coloured spots on the sides of the body, and have bushy gills and a large tail fin. Both terrestrial and forms exist.
Listen to the Indigenous words for “salamander” here!
The Rough-skinned Newt is not easily confused with any other salamander species in British Columbia. It can be easily differentiated from other species within its range by its comparatively ‘dry’ or ‘rough’ skin and colouration.
The Rough-skinned Newt exists in North America from the Alaskan Panhandle south to San Francisco Bay in California, from sea level up to 2700 m. There are reports of isolated populations in Idaho, Montana, and eastern Washington. In British Columbia, they are found along the west coast of the mainland north to the Skeena River, the Gulf Islands, and throughout Vancouver Island.
Rough-skinned Newts breed in shallow aquatic habitats like wetlands, pools, sloughs, and slow streams. Adults and terrestrial juveniles prefer forested areas close to their breeding sites, but adults spend extended periods in aquatic habitats during the spring and early summer, and a high proportion of individuals remain aquatic for their entire life. For terrestrial individuals, cover objects such as logs, rocks, and dense vegetation are important microhabitat features. In large, permanent water bodies that do not freeze over, Rough-skinned Newts may remain active throughout the entire winter. Individuals that are found in shallow or seasonal wetlands will hibernate in terrestrial habitats in underground cavities or under cover objects, especially rotting logs.
Rough-skinned Newts spend the majority of the breeding season in aquatic habitats, and terrestrial adults will migrate to these habitats in spring. Breeding generally happens in the spring, although some neotenic adults will breed in the fall. The male will deposit a sperm packet (spermatophore) that the female will pick up with her. Unlike other salamander species, female Rough-skinned Newts lay each egg singly across the breeding habitat, attaching them to vegetation underwater. Eggs hatch after 3-4 weeks, and larvae will metamorphose in late summer or the following year, depending on local conditions. Rough-skinned Newts reach sexual maturity after 4-5 years, and can live over 12 years.
Both adult and larval Rough-skinned Newts are carnivorous and eat a variety of invertebrate prey including slugs, snails, crustaceans, worms, and amphibians’ eggs and larvae.
Rough-skinned Newts are one of the most common amphibians in coastal British Columbia due to their dense populations, low vulnerability to predators, and ability to occupy a variety of habitats. However, the destruction of forest and wetland habitat may pose a threat to some populations, especially where human density and disturbance is high. Local threats to individual populations can include pollution from road and agricultural run-off, and introduced pathogens.
Did You Know?
The toxin that Rough-skinned Newts create is a tetrodotoxin, similar to that created by pufferfish, and the level of toxicity varies throughout its range. Gartersnakes are one of the main predators of Rough-skinned Newts, and have evolved a resistance to the toxin. In response, Rough-skinned Newt populations that are heavily predated by Gartersnakes develop more potent toxin, leading to an arms-race between the two species. Gartersnakes have been shown to assess their level of resistance to each individual newt, rejecting individuals that taste too ‘poison-y’. Those newts that were rejected by Gartersnakes tend to survive, and pass on their genes, as there are reports of newts being attacked and ingested for over 50 minutes and escaping with their lives.
When threatened, the Rough-skinned Newt will roll over to expose its bright orange belly which serves as a warning signal to predators, as they are the most toxic amphibian in the Pacific Northwest. One newt contains enough poison to kill 25,000 mice.