Shenandoah salamander  (Plethodon shenandoah)

The Shenandoah salamander is classified as Vulnerable (VU) on the IUCN Red List (1).

A small and slender-bodied amphibian (3), the Shenandoah salamander (Plethodon shenandoah) is endemic to the Appalachian region of the United States. This unique mountainous region is home to 14 percent of the world’s 535 salamander species, making it an extraordinary hotspot of salamander biodiversity (4).

The Shenandoah salamander occurs in two distinct, striped or unstriped colour morphs. In the unstriped morph, the back of the Shenandoah salamander is uniformly dark, sometimes with scattered brassy-coloured markings. The striped morph is dark on the back, characterised by a narrow red or orange-yellow stripe which runs along the length of the body (2) (3) (5) (6).

In both morphs, the Shenandoah salamander has a light coloured throat, black and white spots along the sides of the body, and a dark belly which has white or yellowish mottling (2) (3).   

The Shenandoah salamander is known from small, isolated areas in Shenandoah National Park, Virginia (1) (2) (6) (7). It is restricted to three separate mountains, Hawksbill Mountain, The Pinnacles, and Stony Man Mountain, at elevations above 800 metres (1) (3) (5) (7).

The Shenandoah salamander is restricted to the steep, north-facing, rocky scree slopes of just three mountains in Shenandoah National Park, where it is mostly confined to pockets of moist soil and vegetation in an otherwise dry habitat (1) (2) (6) (7).

The optimal habitat for the Shenandoah salamander is forested mountainous areas with high moisture content. However, this species is excluded from this more favourable habitat as a result direct competition with the native eastern red-backed salamander (Plethodon cinereus) (1) (5) (7) (8).

The Shenandoah salamander is a member of the family Plethodontidae, commonly known as the lungless salamanders. Without lungs, species in this family have adapted to respire through the surface of the skin and the mouth lining. To absorb oxygen in this way it is vital that the skin is kept moist, a factor which has restricted the lungless salamanders to living in damp, moist areas (2) (9). These species are also active for only brief periods, usually at night or during wet weather (2) (7) (9).

During the day, the Shenandoah salamander will shelter under rocks and logs, or in rocky crevices below the ground (6). At night or after rainfall, the Shenandoah salamander will emerge from its hiding place and forage among the leaf litter and in low vegetation, where it searches for a wide variety of invertebrates, such as mites, flies, small beetles and springtails (2) (5) (7).

The Shenandoah salamander breeds in late spring or summer. The female lays a clutch of between 3 and 19 eggs in a damp log, moss, or in a moist crevice underground (2) (5) (7). The Shenandoah salamander is unusual among salamanders as there is no aquatic larval stage, and the young develop completely inside the egg (1) (2) (6) (7). The eggs are guarded continually by the female during incubation, which lasts for one to three months (2) (3) (5).

One of the biggest historical threats to the Shenandoah salamander is competition with the more aggressive and widespread eastern red-backed salamander. This species effectively excludes the Shenandoah salamander from more favourable habitats by driving it from moist soil pockets and forcing it to inhabit the drier areas of rocky scree (1) (5) (7) (9) (10).

Climate change is also considered to be a major concern for populations of the Shenandoah salamander, and is likely to exacerbate the problems created by competition with the eastern red-backed salamander (1). As a mountain-dwelling species, the Shenandoah salamander lives at the limit of its natural climatic distribution (7). The Appalachian region is expected to warm by around two to six degrees Celsius over the next century, which will have considerable impact on the Shenandoah salamander’s ability to survive in its already marginal habitat (4) (10).

Rising temperatures and decreasing frequency of rain will also reduce the level of moisture in the surrounding environment, which will directly affect the Shenandoah salamander’s activity cycles, altering the timing and frequency of key events such as foraging and breeding. Rising and more variable temperatures are also thought to be a key driver in the spread of disease and pathogens, such as the devastating chytrid fungus which has been implicated in the local extinction of many amphibians worldwide (4).

Other threats to the Shenandoah salamander include pollution, altered soil chemistry due to the acidification of soil and freshwater, the loss of leaves on trees because of invasive plant pest species, energy production and mining, fires, and habitat fragmentation. Human development and recreation also pose a threat to the Shenandoah salamander (1) (2) (4) (5) (8).  

The three populations of the Shenandoah salamander are all found within the Shenandoah National Park. It is also listed as Endangered by the Virginia Department of Game and Inland Fisheries and as Endangered by the U.S. Fish and Wildlife Service, meaning that it is the focus of much conservation attention (1) (7) (8).

A recovery plan has been put in place which aims to minimise human impacts in the National Park on the Shenandoah salamander, as well as to the populations of the eastern red-backed salamander (2) (7). Management actions, which are aimed at increasing population numbers of the Shenandoah salamander, relocating individuals, or reducing naturally occurring competitors, are currently being discouraged to avoid having unwanted effects on natural interactions, particularly between the Shenandoah salamander and the eastern red-backed salamander (2).

The major aims of the recovery plan for the Shenandoah salamander include reducing the effects of forest pest species, determining and minimising the effects of pollution on the Shenandoah salamander, and monitoring the impact of park maintenance and other management activities conducted in this species’ habitat. Additionally, a long-term monitoring programme has been implemented to track the distribution and abundance of both the Shenandoah salamander and the eastern red-backed salamander. Public awareness campaigns are also being carried out in Shenandoah National Park to educate visitors about the importance of this rare, endemic salamander to the region (2).

Find out more about the conservation of the Shenandoah salamander:

• U.S. Fish and Wildlife Service (1994) Shenandoah Salamander (Plethodon shenandoah) Recovery Plan. Hadley, Massachusetts. Available at:
  http://www.fws.gov/ecos/ajax/docs/recovery_plan/940929a.pdf