Reptiles
Sharp-Tailed Snake
Contia tenuis · also called sharp-tailed snakes
Beneath a damp log on the Pacific coast, a small snake pins a slug in place with a sharp spine on the tip of its own tail, then works a set of unusually curved teeth into the slippery prey, a specialised hunting method that has quietly earned this species a diet almost no other snake bothers competing for.
Overview
The sharp-tailed snake, Contia tenuis, is a small, slug-specialised snake native to forest and grassland habitat along the Pacific coast of North America, from British Columbia south through California. Its unusual tail spine, distinctively curved teeth, and naturally patchy, localised distribution make it one of the more specialised and conservation-relevant small snakes on the West Coast.
A predator built for one difficult prey
Slugs are slippery, defensive, and awkward for most predators to handle, but the sharp-tailed snake has evolved exactly the tools needed to overcome that difficulty, turning an otherwise hard-to-eat prey item into its primary food source.
Status
Near Threatened, with naturally patchy populations across its Pacific coast range and particular vulnerability at the northern edge of its distribution in British Columbia due to habitat loss and fragmentation.
Sharp-Tailed Snake: common questions
Why does the sharp-tailed snake have a spine on its tail?
This species uses the small, hard, pointed spine at the tip of its tail to help pin down slippery slug prey against the ground, anchoring its own body so it can manoeuvre into position and work its curved teeth into the slug without losing its grip on such a slick and mucus-covered target.
Why does the sharp-tailed snake need specially curved teeth?
Because slugs are covered in slippery mucus and can be difficult to hold onto, this species has evolved distinctively long, curved teeth that grip and help draw the slug steadily into its mouth, an adaptation shared by very few other snakes since most do not specialise so heavily on slug prey.
Why is the sharp-tailed snake considered near threatened?
This species naturally occurs in scattered, often isolated populations rather than continuously throughout its range, and populations at the northern edge of its range in British Columbia in particular face ongoing habitat loss and fragmentation, a combination of naturally patchy distribution and habitat pressure that has contributed to its classification as a species of conservation concern.
When is the sharp-tailed snake most active?
This species is most active during cool, moist periods such as spring and autumn, when conditions favour both its own activity and the availability of the slugs it feeds on, retreating underground during the hottest and driest parts of summer when the surface becomes too dry for comfortable activity.