VIPERA CAUCASICA

Vipera berus dinniki Nikolsky, 1913. Reptiles and amphibians of Caucasus. Tiflis, Caucasian museum: 176 – 179. Terra typica: Malaja Laba river valley (the Northern Caukasus) and Georgia.
Vipera xanthina – Dinnik, 1902: 34.
Coluber berus dinnicki – Nikolski, 1916: 240 – 244.
Vipera tigrina Tzarewsky, 1916. Zoological museum, Akademy of Sciense, v. 26: 32 – 37. Terra typica: the Northern Caucasus, Kubanski region.
Vipera berus dinniki – Dinnik, 1926: 16; Krasovski, 1933: 94.
Vipera ursini kaznakowi – Knoepffer et Sochurek, 1955: 185 – 188.
Vipera ursini renardi – Kramer, 1961: 715.
Vipera kaznakowi – Terentiev and Chernov, 1936: 55 (part.), 1949: 270 (part.); Bannikov, 1977: 323 – 324 (part.).
Vipera kaznakovi – Mertens und Wermuth, 1960: 201 (part.).
Vipera kaznakowi dinniki     – Vedmederia, 1984: 9 (nomen nudum).
Vipera kaznakowi orientalis – Vedmederia, 1984: 9 (nomen nudum).
Vipera dinniki stat. nov. – Vedmederia, 1986: 56 – 58.
Vipera dinniki – Borkin, Darevski, 1987: 141; Ananieva, 1998: 542 – 544; Dunaev, Orlova, 2003: 316.

The description:

Vipera dinniki, Caucasian mountain viper – a snake of small size with general length about 500 – 650 mm and have short tail (30 – 80 mm). Males differ from females by smaller sizes (their maximal length reaches 412 mm against 486 mm at females), rather longer tail, which is thicker at the basis, greater number of pairs of subcaudal scales and smaller number of ventral scales. Head is usually flat from above and not such wide as at Vipera kaznakovi (Caucasian forest viper), therefore cervical interception is not so well expressed. Frontal-upper edge of the head is round or little sharped in canthus (canthus rostralis). Rostral (intermaxillary) scale is narrow and connected to one or two apical scales (at the Vipera kaznakovi there are usually (up to 91% individuals) two apical scales which connected to rostral). There are 3-4 rows of scales between rostral and frontal scales. The nostril is placed exactly in the centre of nasal scale (at the Vipera kaznakovi – in the centre or more close to the bottom part) and separately from the rostral. There are 1- 2 rows of small scales between large supraocular and frontal scales.The dorsal scales of a body have well expressed keels. There are 134 – 138 ventral scales, 26 – 30(females) and 33 – 34(males) subcaudals, 21 dorsal scales around the middle of body /Larsa Darafeyenka, 2007/.

Vipera dinniki is a highly polymorphic species (photos), there are vipers of different colouration in same small populations, the body colouration is very various, from monophonic bronze-green to citreous-yellow, orange, red, silver-grey with the dark brown or black zigzag which often can be broken off to few separate patterns, especially on the middle part of the body (tigrina form, central part of area). There are individuals with a strip of dark colour on the back. The back zigzag (strip) is separated from sides of a body by more light strips. The ventral side of a body is dark with small light spots or light-grey with dark spots. Juvenile vipers are painted in brown and grey tones and not differ from adults by colouration, patterns and zigzag characters as red-brown juveniles of V. kaznakovi. Vipers from Central and Eastern populations are painted not so colourful as individuals of the West-Caucasian populations. There are melanists (up to 20 – 25 %) in western populations, their juveniles have usual colouration and become black on the third year of life..

Distribution:
Vipera Dinniki area is the Big Caucasian Ridge on the territory of Russia, Georgia and Azerbaijan. It covers a subalpine zone of mountains, both on northern and southern slopes from Fisht-Oshten in the West up to the Eastern Georgia and the North-Western Azerbaijan (up to Lagodekhski and Zakatalski reserves) in the East. The continuous area reaches the Malaja Laba river in the East, and there are number of isolated populations in Karachaevo-Circassia, Kabardino-Balkariya, Ossetia, Ingushetia, the Chechen Republic, Dagestan, Northern and Western Georgia.

The species was described from the upper Malaja Laba river (the Caucasian Nature Reserve, Krasnodar region). In Russia the continuous area covers mountains Chugush, Dzhemaruk, Tybga in the West up to Big Laba river on the East. After a break of an area in Kolkhidian Gate(downturn of the Main Caucasian Ridge between tops Fisht and Chugush), Vipera dinniki appears again on Fisht-Oshten, and further there are only few isolated localities on the last tops with subalpine vegetation.
The spesies enters into Kaznakovi complex, such as Vipera kaznakovi, and was identified as Vipera kaznakovi for a long time. Vipera dinniki is also close to Vipera darevskii, the smallest form from this complex.

Biotopes and way of life:
Viper dinniki, unlike V.kaznakovi, does not live on plain but mainly in subalpine and alpine zones of mountains in a range of heights from 1500 up to 3000 m above see level, occupies subalpine habitats and stony slopes with small trees and bushes more often. Sometimes in river valleys whithout dark pine forests Vipera dinniki and V. kaznakovi occupy togather the same territories, forming a narrow intergradation zone (a combination of morphological characters of both species in some individuals). Occupies upper forest zone, subalpine birch forests, pine forests, rhododendrons, subalpine vegetation zones with fragments of rocks. It is most common on moraines near to small rivers and streams. Places of wintering are located near summer biotopes. Mountain vipers are conservative using their territory : some individuals can be met on the same points during three seasons.
Within the measures of area the species is quite rare, only in some regions of the Caucasian State Biospheric Nature Reserve population density is higher, where up to 30 – 40 individuals/hectare are observed. The active period of V.dinniki lasts from the middle of April to the middle of May up to the end of September – October, depending on height and exposition of a slope. In the spring the vipers appear when the temperature of the ground surface reaches +11C. Males appear earlier. Juvenile vipers continue activity in the autumn longer than adults. Vipers are active during the day and in the evening, when the temperature is about +10 C and weather is cloudy vipers can be observed on the stony surface during all light day long when they support body temperature up to + 30 C using the heat of solar radiation. There is mating period in the end of April – May. In high mountain localities of the Caucasus mating period was observed in the beginning of June. On the northern slopes newborns hatch in August, on the southern slopes – during September. The females give birth to 3 – 5 hatchlings, 4,8 per female (3 – 10 in captivity; Larsa D., 2008) with length of a body 140 – 180 mm (on the average – 146 mm) and weight – 3,1g. Females give birth not every year, apparently, in high mountain regions they have a long-term reproductive cycle, at least two year long. Also in the highland areas newborns leave to places of wintering almost right after birth and do not eat till next spring. Vipers become fertile and can mate on the third year of a life.

Adult vipers feed on lizards (Darevskia, Lacerta sp.) and rodents (Apodemus agrarius, Apodemus uralensis, Sicista caucasica, Microtus majori, Soricidae sp.), sometimes birds.The food specialisation of some separate micropopulations has been observed. Young vipers feed on juvenile lizards and insects (Orthoptera). The viper is capable to pull out by its teeth a prey which has stuck between stones. Venom contains hemolitic toxins which are dangerous to animals and humans.

Density of population in different parts of area is various. It is maximal on stony taluses and moraines of subalpine zone of the Caucasian Nature Reserve: 5-7 vipers/km, in some places of congestions it is possible to meet 10-20, up to 30-40 individuals on hectare were observed. Species is quite rare in the western parts of its area. To the west from the Caucasian Nature Reserve density of population is much lower, in Karachaevo-Circassia – 4 individuals/hectare, in the others localities of Central and Eastern Caucasus vipers are very rare. Natural limiting factors – aridisation of climate and landscapes of the Big Caucasus, changing of mountain-meadow biotopes to mountain-steppe with vipers of ursini – complex V. lotievi occupying them. In a number of sympatry zones (the occurrence of species together in the same area) V.dinniki + V.lotievi (Abishir-Ahuba ridge, Teberda river, Elbrus, Itum-Kalinski hollow, etc.) Vipera dinniki occupies most mesophilic upper mountain zones, V.lotievi – lower semiarid ecosystems. The basic anthropogenous factors influencing number of vipers – collecting snakes, degradation of places of dwelling and  intensive agriculture on subalpine pastures.

Conservation status:
This species is classified Vulnerable (VU) according to the IUCN Red List of Threatened Species with the following criteria: C1+2a (v2.3, 1994). Endemic of the Big Caucasus highlands.
V.dinniki is included to the Red book of the Russian Federation (II category) and in the Red book of Georgia.
About 10000 individuals are protected in the territory of the Caucasian State Biospheric Reserve. Also the species lives on the territory of Teberda and North-Osetiya reserves, and of some conservation territories (Damkhurts, Chilikski, Dautski, Golovinsky, Tliaritinski, etc.). The control over status of populations in all area, the organization of conservation in left-bank of Itum-Kalinskaja hollow is necessary. The special trouble was caused by changing of natural landscapes in upper Mzymta river valley but now this territory is connected to the Caucasian Nature Reserve to protect an unique polymorphic population of  V.dinniki.