Forest steppe otter
| Forest steppe otter | ||||||||||||
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Forest steppe viper ( Vipera nikolskii ), female |
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| Scientific name | ||||||||||||
| Vipera nikolskii | ||||||||||||
| Vedmederja , Grubant & Rudajewa , 1986 |
The steppe viper ( Vipera nikolskii ) is a small to medium-sized venomous snake from the family of vipers (Viperidae). Its distribution area extends from the Ukraine to the catchment areas of the Volga , Dnepr and Don in western Russia . The independence of the species is controversial, it is often assigned to the adder ( Vipera berus ) as a subspecies.
features
Dimensions
The forest steppe otter has an average body length of about 0.85 meters, but in rare cases can reach a maximum length of one meter. The females are significantly larger and at the same time more massive than the males. The head of the snake is relatively narrow in the males and in the females, due to the poison glands behind the eyes, it is heart-shaped and clearly set off behind the neck. The tail of the males is about ten centimeters longer than an average of eight centimeters in the females.
coloring
The basic color of the adult and sexually mature males is lacquer black, which makes them resemble the melanistic individuals of the adder (hell-viper). The underside of the tail is greenish in color in the male.
The females are brown-black, often having a reddish color of the throat and a yellowish-orange tip of the tail. Brown individuals with a black zigzag band are rare. The eyes have a black iris and a narrow, slit pupil . The upper lip shields ( supralabials ) are also black, but have a typical white mottling.
Young animals, regardless of gender, are colored and drawn like young adders. They are usually brown to gray-brown and have a noticeable wavy band along the middle of the back. The top of the head is black, and there is also a dark band from the eye to the corner of the mouth. Gender-specific differences only develop with sexual maturation.
Scaling
On the top of the head, the snake has a multitude of small, smooth scales that merge into the rough scaling of the body in the neck. These are the parietals that have dissolved into many individual scales , whereby the degree of dissolution can vary greatly from person to person. The supraocularia are long and narrow, between these and the frontalia there are usually one to four small scales. The nasals are undivided and large; they contain the nostril in the center. Below the eyes are seven to twelve small scales in one or two rows that separate them from the supralabials . Eight to eleven supralabials form the upper edge of the mouth opening. The rostral is barely visible from the top and stands with two Apikalschilden in contact.
The body scales are strongly keeled. They usually form 21 and rarely 20 or 23 rows of scales in the middle of the trunk. Their size increases towards the belly, the last row has no keel and is accordingly equipped with a smooth surface. The ventral side is covered from 142 to 157 ventralia in the males and 146 to 159 ventralia in the females, followed by an unpaired anal and finally 31 to 37 subcaudalia in the males and 18 to 30 in the females.
distribution and habitat
Geographical distribution
The distribution area of the forest steppe otters is mainly concentrated in an area that extends from the Kharkiv region of Ukraine to western Russia , in the catchment areas of the Volga , the Dnieper and the Don between 50 ° and 54 ° north latitude. Individual finds were reported from Moldova ; in Romania the species is also suspected, but has not yet been proven. A line along the cities of Kaniw , Kursk , Tambow and Dimitrovgrad is assumed to be the northern limit of the distribution . The southern border runs along a line that is formed by the cities of Balta , Znamyanka , Ilowlja Raion on the Don ( Volgograd Oblast ), Volsk and Samara .
Both in the area west of Kaniw and Nowa Sloboda in the Ukraine and north of the Russian area there is an overlap and hybridization zone with the adder, which extends as far as the Mordovia region ( Smolny National Park ), Kungur in the Perm region and into the Bashkir region Nature reserve in Bashkortostan is enough.
habitat
The forest steppe otter lives mainly in the forest steppes of Ukraine and the neighboring Russian areas. These areas are characterized by a macromosaic of deciduous forest stands and meadow steppes . The vegetation is dense and large wetlands are regularly flooded during the year.
Way of life
activity
As with most snake species in Europe, the activity of the steppe otters is very dependent on the outside temperature. It is mainly nocturnal, especially in spring and autumn, it shifts its main activity times to the warmer times of the day. From a daytime temperature of around 10 ° C, the animals are active throughout the day, in summer they then shift their activity into the morning and evening hours and retreat to moist and shady hiding places in the hot hours of the day. At temperatures of over 30 ° C, the animals can generally be found near water.
Between October and December until March or April there is a hibernation of up to 6 months, with mass gatherings of the animals in the vicinity of established wintering quarters for a short time from around September.
nutrition
Like most other vipers, the forest steppe otter is a stalker and does not specialize in certain prey. The prey animals are attacked with a bite through which the viper venom is injected into the body. Then the viper pauses briefly and then begins to pursue the bitten animal, which is weakened due to the poisonous effect and eventually dies. The prey animals are mostly swallowed head end first.
The forest steppe otter mainly hunts small mammals such as rodents and shrews , as well as lizards and frogs . Among the small mammals make voles ( Microtus ), especially the Common vole ( M. arvalis ), the Südfeldmaus ( Microtus rossiaemeridionalis ) and the bank vole ( Myodes glareolus ) a predominant part is the prey. The individual prey spectrum is highly dependent on local supply . In contrast to the adult animals, the young snakes feed almost exclusively on young lizards and frogs, which means that they play a central role in the spread of the forest steppe otters. Play especially the forest lizard ( Zootoca vivipara ), the sand lizard ( Lacerta agilis ), the slow worm ( Anguis fragilis ) and the dice snake ( Natrix tessellata ) among the reptiles and the spadefoot ( Pelobates fuscus ), the moor frog ( Rana arvalis ) and the Sea frog ( Rana ridibunda ) play a larger role among the amphibians.
Reproduction and development
The pairings take place very early in the year after the winter dormancy and the spring moult, usually in the second half of March to the beginning of May. During the mating season, comment fights between the competing males take place, with the opponents straightening their front bodies and trying to push the opponent to the ground.
The gestation period is 130 to 133 days, after which the female gives birth to 12 to 24, on average 15, young between the end of July and the beginning of August. These are only covered by a paper membrane that is pierced within a few minutes after birth ( ovoviviparia ). The young snakes have a body length of about 21 to 25 centimeters with an average weight of 4 to 4.5 grams. The first molt takes place a few days after birth, after which the snakes are independently active and hunt for young frogs and lizards. The snakes lose their light youthful coloring after about four to five moults, at about three to four years of age the animals are sexually mature.
Predators
The forest steppe otters' predators are a number of birds of prey , owls and predators as well as other species of snakes within their range. More detailed studies are not available.
Systematics
The forest steppe otter was first described by Vedmederya, Grubant and Rudaeva in 1986 as a separate species to distinguish it from the adder. A fully grown female animal with her litter of 16 young animals was described as a type series. The name was given in recognition of the achievements of Alexander Mikhajlovič Nikolsky (1858-1942), who described the Caucasus otter ( V. kaznokovi ) in 1909 and the Western Caucasus otter ( V. dinniki ) in 1913 .
The forest steppe otter is systematically classified in the genus Vipera and there often together with the adder ( V. berus ) and some other species in the subgenus Pelias . Svetlana Kalyabina et al. 2002 presented a relationship analysis on the basis of mitochondrial DNA, according to which the forest steppe otter forms a monophyletic group together with the adder and Baran's viper ( V. barani ), whose sister species is the North Iberian adder.
The independence of the species is controversial, as especially the morphological features are largely in the very large range of variation of the adder. The obligatory black coloration of the adult animals and the greenish coloration of the underside of the tail are cited as morphological arguments for independence. There are also recognizable differences in the shape of the hemipenes and the very variable fragmentation of the head shields. Apart from the purely morphological consideration, the poison composition and its proteolytic effect differ . In molecular genetic studies, however, it was found that the differences between forest steppe otters from the Ukraine and southern Russia are greater than those between the Ukrainian specimens and the nominate form of the adder. On this basis and the existing hybridization in the overlapping distribution area, the classification of the forest steppe otter as a subspecies of the adder is proposed in addition to the current independence of the species. Alternatively, however, it would also be possible to classify only the Ukrainian animals as Vipera berus nikolskii and to continue to regard the southern Russian animals as a separate species Vipera nikolskii due to the genetic distance .
Snake venom
There is only very limited knowledge about the composition and effects of the poison of the steppe viper. The poison production of the forest steppe otter is probably significantly greater than that of the adder. The frequency of bite accidents is unknown.
Based on spectroscopic analyzes, the venom was found to be very similar to that of the adder. Both vary in the proportions of the individual proteins and can be differentiated spectroscopically. From a purely visual point of view, the poison of the adder is yellowish, while that of the steppe viper is colorless. The proteolytic properties of the forest steppe viper venom are also lower than those of the adder, but the venom effect is stronger. The composition of the poison was analyzed for the first time in 2005, and two previously unknown types of phospholipase A 2 with the names VN5-3 and VN4-3 were discovered.
Like most viper poisons, the poison of the forest steppe viper is primarily hemotoxic , i.e. it destroys cells of the blood and the tissue surrounding them with various proteases . Hemotoxins lead to tissue destruction, internal bleeding and swelling as well as necrosis and are very painful. The most effective components of the poison include proteins that suppress blood clotting and thus together with the tissue-destroying components cause internal bleeding. In addition, there are small amounts of neurotoxins , which can have a paralyzing effect on the nervous system.
There are a number of polyvalent antivenins available for treatment , which act unspecifically in most Vipera species in Europe and the Middle East. In the case of viper bites, however, these are only used on the advice of a doctor if the symptoms are more severe.
Hazard and protection
The forest steppe otter is not included in the Red List of the World Conservation of Nature Union (IUCN) and is not included in Appendix II of the Bern Convention ( Convention on the Conservation of European Wildlife and Their Natural Habitats ).
supporting documents
literature
- David Mallow, David Ludwig, Göran Nilson: True Vipers. Natural History and Toxicology of Old World Vipers. Krieger Publishing Company, Malabar (Florida) 2003, pp. 258-260. ISBN 0-89464-877-2
- Andrew Bakiev, Wolfgang Böhme, Ulrich Joger: Vipera (Pelias) [berus] nikolskii Vedmerderya, Grubant and Rudaeva, 1986 - forest steppe otter. In: Ulrich Joger, Nikolai Stümpel: Handbook of Reptiles and Amphibians in Europe; Volume 3 / IIB, Snakes (Serpentes) III Viperidae. Aula-Verlag, Wiebelsheim 2005; Pages 63-76. ISBN 3-89104-617-0
- Axel Kwet: Reptiles and Amphibians of Europe . Franck'sche Verlagsbuchhandlung, Stuttgart 2005. ISBN 3-440-10237-8
Individual evidence
Most of the information in this article has been taken from the sources given under literature; the following sources are also cited:
- ↑ a b All information from Bakiev et al. 2005 and Mallow et al. 2003
- ↑ a b c d All information according to Bakiev et al. 2005
- ↑ First description: VI Vedmederya, VN Grubant, AV Rudaeva: K voprosu o nazvanii chiornoy gadyuki lesostepi evropeiskoy chasti SSR (German: On the question of naming the black viper of the forest steppe of the European part of the USSR ) Vestnik Kharkovskogo universiteta 288, pages 82–85.
- ↑ a b Svetlana Kalyabina-Hauf, Silke Schweiger, Ulrich Joger, Werner Mayer, Nicolai Orlov, Michael Wink: Phylogeny and systematics of adders (Vipera berus complex). In: Distribution, ecology and protection of the adder (Vipera berus). Mertensiella 15, 2004 ( summary of the conference report )
- ↑ Wei Gao, Vladislav G. Starkov, Victor I. Tsetlin, Yuri N. Utkin, Zheng-jiong Lin and Ru-chang Bia: Isolation and preliminary crystallographic studies of two new phospholipases A 2 from Vipera nikolskii venom. Acta Crystallographica Section F - Structural Biology and Crystallization Communication 61 (2), 2005. Pages 189–192, PMC 1952264 (free full text)
- ↑ Appendix II of the Bern Convention
