Streamside salamander  (Ambystoma barbouri)

The streamside salamander is classified as Near Threatened (NT) on the IUCN Red List (1).

A large, stout-bodied amphibian of the east-central U.S., the streamside salamander (Ambystoma barbouri) is a rather odd-looking species most distinctive for its small, rounded snout. It is a close relative of the small-mouthed salamander (Ambystoma texanum) and is virtually indistinguishable from this species (2) (3). 

Both of these salamanders have dark brown to black upperparts, with dark grey blotches along the sides of the body. The underparts are usually slightly lighter with paler blotches (2) (3). The male streamside salamander is usually smaller and shorter than the female (2).

Endemic to the U.S., the streamside salamander is mainly found in central Kentucky, south-western Ohio, south-eastern Indiana, and Tennessee, with some scattered populations also in Livingston County, Kentucky, and west Virginia (1).

Occurring in upland deciduous forests, the streamside salamander is usually found underground, or under rocks, leaves and logs. It usually breeds in fast-flowing streams lacking fish predators, but may also breed in ponds (1) (4).

The streamside salamander migrates to breeding areas shortly after the first heavy rains of the season, usually around mid-September. Courtship takes place under rocks, and mating occurs in shallow, muddy waters lacking fish. One or two days after mating, the female streamside salamander deposits a string of 5 to 40 eggs, on the lower surface of flat rocks in flowing streams. Subsequent rows may then be added to form clumps. The eggs, which measure approximately 2 millimetres in diameter, hatch after 9 to 16 days. The larvae begin metamorphosis the following February to May. When they measure around 3.5 to 4 centimetres in length, the young streamside salamanders emerge onto land and seek out underground holes (2) (3) (4).

The main threat to the streamside salamander is the destruction and fragmentation of its habitat by logging, human development and agricultural expansion (1) (4). When forests are cleared, air and soil temperatures increase, humidity decreases and the abundance of prey within the leaf litter changes, which are all detrimental to salamanders. The removal of streamside vegetation also increases water temperature and exposure to ultraviolet radiation, which can kill amphibians. In addition, streams in cleared areas experience increased sedimentation, which degrades salamander habitat by reducing the availability of cover, inhibiting the attachment of eggs to the substrate and adversely affecting embryo development (5). 

Other threats to the streamside salamander include the pollution of stream habitats by acid mine drainage, pesticides, and herbicides, and the channelization of streams (3). Stream drying and flooding may also increase mortality, and these threats may increase in frequency with global climate change (1).

Additional protection is needed for the streamside salamander’s habitat in areas experiencing urbanisation, such as in the Bluegrass Region of Kentucky (1). In Tennessee, there is a need to develop habitat conservation plans to preserve salamander habitat, especially breeding sties (5). Populations should also be monitored in West Virginia as there is currently a lack of data on the status of this species there (4).

For more information on amphibian conservation:

• IUCN Amphibian Specialist Group:
  http://www.amphibians.org/
• Amphibian Ark:
  http://www.amphibianark.org/