Common sharp-tailed snake (Contia tenuis)

A closeup of a common sharp-tailed snake on pebbles and pavement
A common sharp-tailed snake coiled on the ground.  (Don Loarie - Creative Commons)
Category: Reptiles
Ecosystems: Shrubsteppe Riparian areas
State status: Candidate
Vulnerability to climate change (More details)

Moderate

If you see this species, please share your observation using the WDFW wildlife reporting tool or email us at  wildlife.data@dfw.wa.gov. Be sure to include a photo of the species for verification and location (latitude/longitude coordinates) of your observation. 

These snakes are rarely encountered and little studied. The Washington status and of this snake is based on the small number of populations, patchy distribution, and lack of information.

Description and Range

Physical description

This is a diminutive, semi-fossorial species that is usually less than 12 inches long, and rarely exceeds 16 inches. It is reddish brown above with a distinct ventral pattern of alternative black and cream colored bands. It has a short tail that terminates with a small spike-like scale. It is the only snake in Washington with a spine at the tip of the tail. Young snakes are redder in coloration and have more distinct lines down the sides than adult snakes. These snakes have long, re-curved teeth. 

Ecology and life history

In the Pacific Northwest, common sharp-tailed snake are found on the edges of coniferous or open hardwood forest. In Washington, the snakes have been found in: 1) forest openings dominated by Garry Oak often with rock accumulations; 2) riparian/river floodplain with deciduous trees, shrubs and accumulations of decaying down woody logs; 3) shrub-steppe uplands with riparian areas that support deciduous trees and have accumulations of woody debris and rocks.

The snakes are usually found under cover objects in moist rotting logs or stable talus, often near streams or in other damp habitats. Small canopy gaps with rocky substrates, especially those that are south-facing, may be important for thermoregulation, egg development and growth of young. Snakes show evidence of site tenacity, with some snakes found repeatedly under the same cover objects.

Most surface activity occurs when the surface is cool and moist in the spring and fall although observations have been made in most months of the year.

This snake's long re-curved teeth appears to be a specialization for grasping and holding mollusks, the primarily prey of this snake.

Breeding takes place in April or May. Eggs are laid in late June or July and hatching occurs in the fall. Activity is confined to relatively small areas. The greatest distance moved by two study snakes in Canada was 128 and 305 feet. 

Aggregations of these snakes are  observed.

Geographic range

Sharp-tailed snakes occur from British Columbia, Canada into southern California. In Washington, Common sharp-tailed snakes are known from thirteen disjunct areas. West of the Cascade Crest there is an historical record for Pierce County and two recently discovered sites on Orcas and San Juan Islands. East of the Cascade Crest observations are from Chelan, Kittitas, Yakima, Klickitat and Skamania Counties. Almost nothing is known about abundance and some occurrences are based on a single observation.

For a map of worldwide conservation status and distribution of the common sharp-tailed snake, check out NatureServe Explorer.

Climate vulnerability

Sensitivity to climate change

Moderate

Overall, a lack of information exists regarding sensitivity of the sharp-tailed snake to climate change. Sensitivity of this species may be influenced by its occurrence along edges of coniferous or open hardwood forest, which are sensitive to warming temperatures, moisture stress, and changing fire patterns. This species may also exhibit some sensitivity to warmer temperatures and changes in precipitation as they are often associated with moist habitats. However this species is also an egg-layer that could be influenced by soil moisture patterns at oviposition sites; but lack of data on typical oviposition sites makes any prediction of potential changes highly uncertain. Furthermore, this species is a mollusc and soft-bodied invertebrate specialist, so its typical prey base has a high probability of being influenced by soil moisture levels; however, it ability to switch to alternative prey is unknown, so the degree of influence on its prey base is uncertain. Lastly, the species appears to be near-surface active only during periods of higher moisture levels; whether this is directly related to its prey base or its intrinsic moisture requirement or both is unclear. Regardless, the influence of shortened or lengthened periods of surface activity resulting from climate change is uncertain.

Confidence: Low

Exposure to climate change

Moderate

  • Increased temperatures
  • Changes in precipitation
  • Altered fire regimes >Altered prey base as a consequence on one or more of the above

Conservation

This species is identified as a Species of Greatest Conservation Need (SGCN) under the State Wildlife Action Plan (SWAP). SGCN-classified species include both those with and without legal protection status under the Federal or State Endangered Species programs, as well as game species with low populations. The WDFW SWAP is part of a nationwide effort by all 50 states and five U.S. territories to develop conservation action plans for fish, wildlife and their natural habitats—identifying opportunities for species' recovery before they are imperiled and more limited.
This species is identified as a Priority Species under WDFW's Priority Habitat and Species Program. Priority species require protective measures for their survival due to their population status, sensitivity to habitat alteration, and/or recreational, commercial, or tribal importance. The PHS program is the agency's main means of sharing fish and wildlife information with local governments, landowners, and others who use it to protect priority habitats for land use planning.

Conservation Threats and Actions Needed

  • Resource information collection needs
    • Threat: Lack of information on status and distribution.
    • Action Needed: Research, survey and monitoring are needed to understand the status, distribution and habitat needs of this species.
  • Fish and wildlife habitat loss or degradation
    • Threat: Loss of prairie and oak habitat. With observations on San Juan Island, no extant occurrences are known from western Washington. This species is thought to have been associated with prairie habitat in western Washington and most of this habitat type was converted to agriculture or developed for housing.
    • Action Needed: Inventory and outreach to determine if this small, secretive snake still occurs in areas of western Washington other than the San Juan Islands.
    • Threat: Loss of suitable habitat due to harvest of trees. Little is known about threats to this species from habitat alteration but forestry practices likely impact local populations because the loss of canopy changes the moisture regime, increases temperature and removes down woody debris and leaf litter.
    • Action Needed: Identify where this species occurs and work with landowners to conserve habitat features important for the persistence of this species, such as downed woody debris and rock features.

See the Climate vulnerability section for information about the threats posed by climate change to this species. 

Resources

WDFW Publications