Darevsky’s viper  (Vipera darevskii)

Darevsky’s viper is classified as Critically Endangered (CR) on the IUCN Red List (1).

Darevsky’s viper (Vipera darevskii) is a small, secretive species of venomous snake. As is characteristic of most European vipers, Darevsky’s viper is adorned with a distinctive brown zigzag pattern along its back (2). This species has a dark streak extending from the eye to the neck, which terminates before the beginning of the zig-zag body pattern. It also has a conspicuous row of light brown spots along each side of the body that often merge into a continuous stripe (2).

Darevsky’s viper is named in honour of Ilya Darevsky who discovered an isolated population of the species later formally described as Vipera darevskii (3) (4).

Darevsky’s viper is endemic to the Caucasus region that lies between the Black Sea in the west and the Caspian Sea in the east, on the border of Europe and Asia (1).

There are seven known populations of Darevsky’s viper in Armenia, patchily distributed in the south-eastern Javakhet Mountain Range at elevations of 2,100 to 2,700 metres above sea level (1). There is one confirmed population in eastern Artvin Vilayet, Turkey (5), but reports of this species’ presence in Georgia require confirmation (1).

Darevsky’s viper is a highly montane species (1), typically inhabiting subalpine and alpine meadows, interspersed with outcrops of volcanic rock scree (1) (2).

As with all vipers, Darevsky’s viper possesses a pair of hollow, folding fangs, which are used to inject venom into both prey and predators (2). Venom is stored in glands located behind the eye on either side of the head (2). The characteristic zigzag dorsal body pattern of vipers serves two purposes: to camouflage the snake, and to act as a warning signal to potential predators when the snake is spotted (6) (7).

Darevsky’s viper must acquire body heat from the environment to sustain its daily activities, and it therefore spends some of the day basking in the sun (2). As in other European vipers, this basking behaviour typically occurs in the morning (8), shortly after the viper emerges from its overnight retreat site (2).

Due to the small range and rare nature of Darevsky’s viper, little is known of the feeding behaviour of this species (2). It is suspected to feed on similar prey items to other European vipers of the same size, such as reptiles and amphibians (2), both of which are present in the habitat of Darevsky’s viper (8).

The predominant threat facing Darevsky’s viper is overgrazing of vegetation by domestic animals in its restricted habitat, although the recently described population in Turkey may also be threatened by collection for the pet trade (1).

Populations of Darevsky’s viper are considered to be in decline, which, coupled with its extremely small range, places this viper at very high risk of extinction (1). 

Darevsky’s viper is protected from the international pet trade in Armenia, but this appears to be the extent of its current protection (1). However, there is a planned transnational park between Armenia and Georgia that encompasses this species’ range and should provide some level of protection (1).

Recommended conservation measures for Darevsky’s viper include establishing new protected areas to conserve suitable areas of habitat, particularly for the recently discovered population in Turkey. In addition, measures should be taken to prevent overgrazing by domestic livestock within this species’ range (1).

Further studies to confirm the presence or absence of Darevsky’s viper in Georgia and to locate additional populations elsewhere within its range are also required (1).

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more about reptile conservation:

• International Reptile Conservation Foundation:
  http://www.ircf.org/