Southern Torrent Salamander – State Wildlife Action Plan

Southern Torrent Salamander

Photo Credit: John Clare, Flickr

Southern torrent salamanders are highly aquatic and closely associated with cool, clear, permanent water. They are a relatively small salamander with short legs and a short, vertically compressed tail. They have a small, broad head with large, protruding eyes, and a short snout. Southern torrent salamanders are olive to brown in color on their backs, with small black and white spots that extend onto their bright yellow underbelly. Adults can grow 1.5 to 2.5 inches snout to vent. Males are slightly smaller than females, with squared off lobes at the base of the tail. Aquatic juveniles look similar to adults but have short external gills and a finned tail. This salamander has reduced lungs, and obtains oxygen through its skin. They are very intolerant of desiccation (drying out). Similar species to the southern torrent salamander include three other species of torrent salamander (Cascade, Olympic, and Columbia) that were treated as one species until 1992 when genetic analysis showed that there were four distinct species of torrent salamander. All four species are morphologically similar. Rhyacotriton variegatus exhibits a biphasic life history. Eggs are laid in low-flow headwater streams where larvae remain for up to five years. Juveniles are restricted to cold, clear streams; metamorphosed adults continue to occupy these stream habitats, but also leave natal streams and move to forests during wet conditions for foraging and dispersal. Adults are rarely found more than a few meters from stream banks.

Overview

  • Species Common Name Southern Torrent Salamander
  • Species Scientific Name Rhyacotriton variegatus
  • State Listing Status Sensitive

Ecoregions

Special needs

Southern torrent salamanders inhabit cold, small-order permanent and intermittent mountain streams, and low-flow headwater streams and seeps in conifer or mixed conifer forests. They prefer loose gravel stream beds with low amounts of fine sediment. High-gradient, small streams are important for breeding, larval, and dispersal habitats. Adults use moist upland riparian forests during the wet season for dispersal and foraging and may move vertically in the substrate during hot or dry periods.

Limiting factors

The Southern torrent salamander has limited dispersal capabilities. Adults are highly sensitive to desiccation and are dependent on cool, well oxygenated water. Fertilizer, herbicides, and other pollutants may negatively affect this species. Larvae are vulnerable to changes in stream temperature and flow, and these impacts may be exacerbated by climate change and water diversion for marijuana cultivation. Disturbances to forest cover (timber harvest, landslides, wildfire, and other habitat disturbances), dry forest conditions, impassable culverts and large rivers, and roads can decrease habitat connectivity and limit gene flow.

Conservation actions

• Retain stream buffers to maintain cool water temperatures and water clarity.
• Minimize habitat alteration or disturbances that increase erosion or siltation.
• Improve habitat connectivity.
• Manage for well-distributed populations of southern torrent salamanders throughout Oregon to preserve genetic diversity.
• Increase enforcement efforts to combat illegal water use.
• Identify and prioritize protection and management of habitats with higher climate-resiliency.

Key reference or plan

Treading Water: Conservation of Headwater-Stream Associated Amphibians in
Northwestern North America Read here

Life History Traits