Meadow Viper

Description and biology

The meadow viper, also called Orsini’s viper, is Europe’s smallest viper. It is a venomous (poisonous) snake. Males average about 16 inches (41 centimeters) long, while females are larger, up to 2 feet (60 centimeters) in length.

The meadow viper preys upon insects, especially grasshoppers, as well as small mammals and lizards. Females give birth to live young (rather than laying eggs).

There are several subspecies of the meadow viper. Vipera ursinii rakosiensis, the subgroup found in Hungary and parts of Austria, is the most threatened, and many believe it is on the verge of extinction.

Habitat and current distribution

Meadow vipers currently exist throughout Europe, but in fragmented populations that are isolated from each other. The species prefers either lowland meadows or southern–facing mountain pastures at elevations between 4,600 and 8,000 feet (1,400 and 2,440 meters).

Meadow vipers are most often found in steppes (vast, treeless, flat tracts of land in south-eastern Europe and Asia) or semi–steppes environments. Each of the different subspecies of meadow viper has its own range, and in some areas meadow vipers remain relatively abundant, though still threatened.

The highly endangered Hungarian meadow viper, Vipera ursinii rakosiensis, now occurs only in the Great Hungarian Plain between the Danube and Tisza rivers and in the Hansa’g Nature Reserve in the north-western part of Hungary.

History and conservation measures

Throughout Europe, the meadow viper has been endangered by the loss and fragmentation of its habitat due to agriculture, road–building, and livestock practices. These small snakes have also been illegally captured for trade as terrarium (small, transparent cages, often made of glass or plastic) animals.

The Hungarian subspecies of meadow viper once ranged throughout suitable habitats in Hungary, the easternmost part of Austria, Transylvania (Romania), and northern Bulgaria.

The range of this subspecies has been greatly fragmented by human–related habitat disturbance. Croatia has had protective measures for the meadow viper in place since 1965.

Because the Hungarian subspecies is close to extinction, the Council of Europe Convention on the Conservation of European Wildlife and Natural Habitats Standing Committee has recommended the government of Hungary:
  1. establish protected meadow habitats in the range of the existing meadow viper populations; 
  2. open up surrounding habitats where the species once occurred; and 
  3. prohibit the burning of farm land in Hungary.

Scientists believe that the Hungarian subspecies of meadow viper, because of its very low population and the isolation of the various remaining groups, is experiencing what is called inbreeding depression.

This occurs in a small, closed population in which all individuals eventually become related to one another by descent. Over time, this will cause a loss of genetic diversity, or lower the number of biological units that pass on hereditary traits to the next generation.

The effects of inbreeding depression in the wild build up over time, most seriously affecting the reproductive health of the animals, thus making them more vulnerable to extinction.

One way to increase the genetic diversity among the Hungarian meadow vipers is to begin a captive–breeding program using genetically screened vipers.