Orlov's viper  (Vipera orlovi)

Classified as Critically Endangered (CR) on the IUCN Red List (1).

Poorly known and extremely rare, Orlov's viper was only described to science in 2001 when it was separated as a distinct species from the endangered Caucasian viper (Vipera kaznakovi) (1) (3). In common with other vipers, this stout-bodied snake has a roughly triangular head which is distinct from the neck, and long, venomous fangs, which are folded against the roof of the mouth when not in use (2) (4) (5) (6) (7). Typically, the body is pale grey-brown in colour, with a dark zigzag dorsal stripe, and dark spots and blotches along the sides. However, the body colour and pattern of this species is highly variable, with some individuals being tinged yellow or reddish, while others may be all bronze or black (2).

Orlov's viper is endemic to the Krasnodar Territory in Russia, where it occurs in small, highly fragmented populations in the lowest north-western part of the Great Caucasus, from Papai mountain in the west, to the peak of Bol'shoy Pseushkho mountain in the east (1) (4) (8). All records of this species have been from between 200 and 950 metres above sea level (1). edit

Orlov's viper has been recorded in a range of Mediterranean and sub-Mediterranean habitats, including clearings near to rivers, meadows, transformed steppes and juniper forest ecotones (1).

Having only been described to science in 2001, almost nothing is currently known about the natural history of Orlov's viper (1) (2). While its food preferences have not been examined in the wild, captive Orlov's vipers exhibit little dietary discretion, eating mice, lizards, frogs and insects with no apparent preference (9).

Some vipers lay eggs but the vast majority reproduce ovoviviparously, whereby the young are born live, but undergo development within membranous eggs retained inside the female's body (6) (7).

With a population estimated to comprise less than 250 mature individuals, fragmented into poorly connected sub-populations, Orlov's viper is dangerously close to becoming extinct in the wild. Like many other reptile species around the world, the principal threat to its survival is the uncontrolled collection of wild specimens for the pet trade (1). The poaching of rare species is alarmingly widespread in the mountains of the Caucasus, with the illegal wildlife trade being one of the main conservation concerns in the region (10).

Owing to its precarious status in the wild, Orlov's viper is in dire need of a raft of immediate conservation measures. The main priorities include the establishment of reserves where this Critically Endangered snake will be protected from poaching; the development of conservation legislation, particularly concerning the regulation of trade; the implementation of education programmes for local people; and further research into the species' natural history, distribution and population dynamics (1).

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

To find our more about conservation in the Caucasus, visit:

• The Critical Ecosystem Partnership Fund:
  http://www.cepf.net/where_we_work/regions/europe_central_asia/caucasus/Pages/default.aspx

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