Vipera Darevskii - Habitats and Ecology

Habitats and Ecology

Mountain ridges supporting Darevsky's viper have very unique climate conditions. They compose the coldest and the most humid region of the Armenian Highland. An average annual precipitatiion here is about 1000 mm. Even at the hottest and driest months of July and August, hot days lead to intensive evaporaiton of humidity and cloud formation. Almost every evening, aggregating clouds release some, often heavy showers and re-moisturize the environment. At nights temperature regularly drops down to just 4-6 C, and morning sun-rays regularly have to cut through the dense fog, before they reach the east facing slopes and provide heat necessary for functioning of this viper. In some north-facing patches close to the watersheds and summits of mountain ridges some residucal snow and ice never melts. Such a patches as a rule unsuitable for snakes. Suitable patches of rocky deposits are mainly situated on steep and the wormest south and south-east facing slopes of deep mountaneous valleys within the elevation range of 2300–3000 m a.s.l.

High mountaneous moirains as well as outcrops of the bedrock surrounded by alpian grasslands are being utilized as the main habitat by this snake. Deposits of rocks provide snake with deep hybernation dens, but also serve as daily shelters and protection from overheat, overcooling as well as predators. Also rocky deposits support important food resources: rock lizards (mainly Darevskia valentini) and small rodents(Microtus ssp.). Darevsky's vipers are diurnal snakes and during the day they often move inside the rocky deposits to maintain optimal temperature of their body, which is about 26-28 C. Very little is known about natural enemies of this viper. Remains of this snake were found in the feaces of Beech Marten (Martes foina nehringi).