Allegheny Mountain dusky salamander COSEWIC assessment and status report: chapter 2

Species Information

The Allegheny Mountain Dusky Salamander, Desmognathus ochrophaeus, is a small, slender salamander belonging to the family Plethodontidae (lungless salamanders). Mature salamanders average 70 to 100 mm in total length. Adults typically have a light stripe down their back that extends from the head to the tail. This stripe is straight-edged and varies in colour from grey, brown, tan, yellow, and orange, to red depending on age and sex. The stripe also commonly contains a row of chevron-shaped dark spots down the middle.

 

Distribution

Desmognathus ochrophaeus is found commonly throughout the Appalachian Mountain System of eastern North America. In Canada, the entire known distribution consists of two isolated locations along the Canada/U.S. border, one in Quebec and one in Ontario. Allegheny Mountain Dusky Salamanders were first discovered in Quebec in 1988, and are found on the north side of Covey Hill, at the northernmost edge of the Adirondack Mountains in extreme southwestern Quebec. The Quebec range is likely restricted to the northernmost edge of the Adirondack Mountains, an area of roughly 20 km (east to west) x 5 km (north to south).A second distinct Canadian population was discovered in the Niagara Gorge of southern Ontario in 1989 (Kamstra 1991), although it was not recognized as D. ochrophaeus until 2004. The total distribution of D. ochrophaeus in the Ontario site is limited to just over half a hectare.

 

Habitat

Desmognathus ochrophaeus is generally found within the vicinity of forested brooks, mountain cascades, springs, or seeps. It uses this habitat to forage, as well as for overwintering and brooding. Shelter is provided in wet cavities along stream edges or seeps, or under stones, leaf litter, or logs.

 

Biology

Desmognathusochrophaeus is nocturnal. Salamanders remain hidden beneath cover objects during the day. They emerge at night to forage and feed on a variety of invertebrates. During the colder winter months, they hibernate in underground retreats. Mating and egg laying occurs in the fall and spring following an elaborate courtship ritual. The female lays a clutch of eggs in a moist depression and remains with the eggs until hatching. The larval stage may last up to 8 months and requires moist conditions but not necessarily a body of water.

 

Population Sizes and Trends

There are not currently adequate data to indicate sizes and trends of the two D. ochrophaeus populations in Canada.

 

Limiting Factors and Threats

For both Quebec and Ontario, the main threats to this species are those that could affect the water table, either through human activities or climatic variations. Fluctuations in water flow, or contamination of water sources, are likely to have large impacts. In Quebec, physical barriers (e.g., roads, cultivated fields) could compromise the species' movements. Logging at and around the Quebec locality could also pose a threat to this species by destroying terrestrial habitat, increasing siltation, and by altering hydrological regimes. In Ontario, any human activity that could alter the quantity, quality, or temperature of the water supply, or impose change to the surrounding forest habitat could be detrimental. Furthermore, because of their minute ranges, both populations are highly susceptible to stochastic environmental events.

 

Special Significance of the Species

The species has no direct economic value and little cultural significance to the Aboriginal community. However, it has intrinsic value as part of Canada’s natural heritage, and is of interest to herpetologists and naturalists. Because of its secretive habits and nocturnal activity, it is unlikely to be seen by anyone other than the handful of people specifically doing research and monitoring.

 

Existing Protection

This species is not yet designated in Quebec. It is currently on a list of species likely to be designated threatened or vulnerable (Gouvernement du Québec 2006). The species is, however, protected by the “Loi sur les espèces menacées ou vulnérables” (L.R.Q. chap. C-61.1), which prohibits buying, selling or keeping in captivity. Furthermore, Article 22 of the “Loi sur la qualité de l'environnement” (L.R.Q, chapitre Q-2) offers protection against unregulated degradation of environmental quality.

In Ontario, D. ochrophaeus is not currently listed as a species at risk because of its recent discovery in the province. COSSARO (Committee On the Status of Species At Risk in Ontario) recommendations for the species are currently under review.

At the federal level, the Great Lakes/St. Lawrence population of D. ochrophaeus at Covey Hill, Quebec, is protected under the Species at Risk Act (SARA) and listed as Threatened on Schedule 1. It was previously designated as Threatened (D2) by COSEWIC in 2001 because of its extremely restricted range in Canada, its increasingly isolated populations, and its susceptibility to habitat alteration.