Northern Dusky Salamander Carolinian population
Scientific Name: Desmognathus fuscus
Taxonomy Group: Amphibians
COSEWIC Range: Ontario
COSEWIC Assessment Date and Status Change: May 2012
COSEWIC Status: Endangered
COSEWIC Status Criteria: B1ab(iii)+2ab(iii); D1
COSEWIC Reason for Designation: This species is restricted to one small creek sustained by groundwater seepage on the steep slope of a gorge vulnerable to erosion, atmospheric deposition of pollutants and habitat acidification. The population is small and susceptible to ecological, demographic and genetic stochasticity.
COSEWIC History of Status Designation: The species was considered a single unit and designated Not at Risk in April 1999. Split into two populations in May 2012. The Carolinian population was designated Endangered in May 2012.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2017-06-02
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
The Northern Dusky Salamander (Desmognathus fuscus)is a member of the family Plethodontidae (lungless salamanders). Adults are usually brownish with a light dorsal stripe that continues onto the first portion of the tail. The body is sparsely covered with dark spots that are concentrated on the sides and becomes white or grey on the underside. Old individuals tend to be uniformly dark brown or black. Younger life stages have five to eight pairs of dorsal blotches or spots. Both adults and larvae have larger hind legs than forelegs and a pale line extending from the eye to the rear of the jaw. The Northern Dusky Salamander is the most widespread representative of its genus in Canada. [Updated by COSEWIC- May. 2012]
Distribution and Population
The Northern Dusky Salamander is distributed throughout the mountainous regions of eastern North America. The Canadian distribution accounts for about 5% of the global range and includes a small area in the Niagara Gorge in Ontario, three large areas in Quebec (the Adirondack Piedmont, the Appalachian uplift, and the north shore of the St. Lawrence River), and scattered areas in southern New Brunswick. Within its range, the Northern Dusky Salamander occurs discontinuously usually in high elevation, low-order streams, in forested habitat. There are two designatable units, the Carolinian DU in Ontario, and the Quebec/New Brunswick DU. Although considerable sampling effort has been invested in some parts of the species’ Canadian range, current data do not allow an accurate estimate of population sizes or trends. In Ontario, the species is confined to a single small location in the Niagara Gorge. Estimates suggest the Ontario population size is likely fewer than 250 adults. The species is widespread in Quebec and New Brunswick; however, local densities are usually low. In each province six new populations have been discovered in the past few years as a result of increased targeted searches. Accordingly, the extent of occurrence has slightly increased, reflecting greater search effort rather than population growth or the establishment of new populations. On the other hand, some populations seem to have disappeared. [Updated by COSEWIC- May. 2012]
The Northern Dusky Salamander inhabits the vicinity of springs, seepages, and small tributaries of clear headwater streams in forested habitats. The species takes refuge under protective cover (rocks, logs, moss or leaf litter) or in cool subterranean retreats near stream edges. It forages along the streamside, mostly in terrestrial habitat. Females usually nest in cryptic microhabitats near a stream’s source where soil is saturated. Larvae are strictly aquatic and remain in interstitial spaces among rocks of the streambed during their development. In winter, larvae remain in shallow running water, whereas adults retreat to subterranean refuges with constant water flow. Habitat availability and quality are optimal in undisturbed watersheds with abundant forest cover.[Updated by COSEWIC- May. 2012]
The Northern Dusky Salamander has a biphasic life cycle that includes an aquatic larval stage of 7 to 16 months, followed by a semi-aquatic adult stage. Sexual maturity is attained at 3 to 4 years of age. Mating takes place in the spring or fall and females lay eggs annually in late spring and summer. Fecundity increases with body size, and clutch size varies geographically between 8 and 45 eggs. Females remain with their clutches until they hatch 45 to 60 days after oviposition. Maximum life span is about 10 years. Northern Dusky Salamanders are particularly vulnerable to water loss, and are most active at night. The threat of desiccation makes the species a poor overland disperser. Movements occur primarily along the stream channel usually within a few metres of water’s edge. Adult home range is small (0.1 m² - 3.6 m²). The species consumes aquatic and terrestrial invertebrates opportunistically. It lacks defence mechanisms against predators, but is capable of tail breakage. Fish, snakes, crayfish, birds, small mammals and larger salamanders are the main predators of the Northern Dusky Salamander. Hybridization between Northern Dusky Salamanders and Allegheny Mountain Dusky Salamanders occurs infrequently. [Updated by COSEWIC- May. 2012]
Changes in water supply and quality due to human activities are the main threats to the Northern Dusky Salamander in Canada. Decreased groundwater supply to the species’ habitat can be catastrophic to local populations. Artificial increase in discharged water volumes in some areas is also likely to disrupt salamander populations and reduce suitable microhabitats. Runoff water from urban, industrial and agricultural areas can contaminate groundwater and waterways. Heavy metal contamination from atmospheric deposition is likely responsible for the disappearance of the species in Acadia National Park in Maine. Stream acidification is also a concern to the species as nearly 40% of the mountain streams in the southern Appalachians show signs of acidification. Timber harvesting, windfarms, and watershed urbanization reduce water supply, water quality and microhabitat availability. Siltation is one of the most adverse effects of timber harvesting because interstitial spaces used by salamanders for foraging, shelter, nesting, and overwintering are lost. At the watershed scale, urbanization has caused the disappearance of the Northern Dusky Salamander in Mount Saint-Hilaire National Park (Quebec) and other areas. Introduction of predatory fish, particularly Brook Trout, is a threat to the species. [Updated by COSEWIC- May. 2012]
The Northern Dusky Salamander, Carolinian population, is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Northern Dusky Salamander (Desmognathus fuscus), Carolinian population, in Canada
Status First posting on SAR registry
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
8 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Related Information (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2011-2012 (2012-10-05)Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (September 1, 2011 to September 30, 2012) from November 21 to 25, 2011 and from April 29 to May 4, 2012. On February 3, 2012, an Emergency Assessment Subcommittee of COSEWIC also assessed the status of the Tri-colored Bat (Perimyotis subflavus), the Little Brown Myotis (Myotis lucifugus), and the Northern Myotis (Myotis septentrionalis). During the current reporting period COSEWIC assessed the status or reviewed the classification of 67 wildlife species. For species already found on Schedule 1 of SARA, the classification of 32 species was reviewed by COSEWIC and the status of the wildlife species was confirmed to be in the same category (extirpated - no longer found in the wild in Canada but occurring elsewhere, endangered, threatened or of special concern). The wildlife species assessment results for the 2011-2012 reporting period include the following: Extinct: 1 Extirpated: 4 Endangered: 29 Threatened: 10 Special Concern: 15 Data Deficient: 2 Not at Risk: 6 Total: 67 Of the 67 wildlife species examined, COSEWIC reviewed the classification of 49 species that had been previously assessed. The review of classification for 26 of those species resulted in a confirmation of the same status as the previous assessment (see Table 1a).