The adder (Vipera berus)

Vipera berus

The adder (The common viper) is the viper species with the widest range, both in Europe and in Romania, being found from Great Britain, in the west to Sakhalin Island on the Pacific Coast, in the east and from northern Sweden to the Balkan Peninsula [5, 7, 12]. Vipera berus is the northernmost species of snake in the world and it can be found north of the Northern Arctic Circle [1].

The species has been intensely studied by numerous researchers, three of the sub species of the adder being accepted: berus, bosniensis and sachalinensis [12]. In addition to these three subspecies, the taxonomic statute of other three taxa is still debated and opinions differ from one author to another. Thus, Vipera seaoeniVipera barani and Vipera nikolskii are considered to belong to the Vipera berus complex.

The Geographic Range of Vipera berus in Europe (Gasc et al. 1997) - [7]
The Geographic Range of Vipera berus in Europe (Gasc et al. 1997) – [7]

The adder taxonomy was little studied in Romania but it is generally accepted that all the populations belong to the V. b. berus subspecies [9, 19].

In 1956 Vancea & Banyai described a specimen in the Ciuc Mountains as belonging to Vipera berus bosniensis subspecies, but this specification was deemed to be incorrect considering that Vipera berus berus was also mentioned in the respective region. In Romania, Vipera berus was mentioned throughout the entire Carpathian basin and also in the hilly regions between the rivers Prut and Siret [2, 5, 4, 20, 11, 9, 3, 4, 16, 17, 18].

The most complex thesis on the adder, developed in Romania is the one made by herpetologists Funh & Vancea, 1961.

The Geographic Range of Vipera berus in Romania (Fuhn & Vancea 1961) - [5]
The Geographic Range of Vipera berus in Romania (Fuhn & Vancea 1961) – [5]

Morfology. Vipera berus is a medium size species which doesn’t normally exceed 80 cm in length. Its head is covered in plates and scales, its snout truncated or obtusely rounded [5, 12]. It has a short thick body, the edge of the snout is raised into a low ridge and it is rarely concave and its superior contour is a little bit rounded or truncated in front. The eyes of the females are generally smaller than the ones of the males. The tale of the males is comprised 5,5 – 9 times in the total length and that of the females 8 – 10 times [5, 12].

Colour. Most Vipera berus populations have highly pronounced sexual dimorphism and dichromatism. The females are larger and their dorsal side is brown, the zig-zag stripe on their backs being dark brown and rather indistinct. During the mating season males have light grey to silver dorsal colour and a dark brown or black zig-zag stripe which is very well contoured [5, 6, 15]. Black individuals with a velvety polish on their back are often observed almost across the entire range of the species. Such individuals do not have the stripe on their back, and their abdomen is the colour of slate (dark grey) [12].

Ecology. The adder can be found in different biotopes within its vast range. It prefers forest limits and clearings, sunny shrubs and mountain slopes up to 2500 m. In Romania it can be found from the hill region up to the mountain region. It feeds on small rodents (mice, shrews), moles, little birds, lizards, frogs and the youngsters feed on insects. It usually kills its prey by using its venom and only afterwards it swallows it. It hibernates starting from October and becomes active again from early April. Mating takes place in April and May. The number of the newborns in August varies between 5 and 18 and depends on the size of the animal. The newborns have between 140 and 230 mm in length [5, 6].

Vipera [berus] nikolskii (Vedmerja, Grubant et Rudaeva 1986) also known as Nikolsky’s viper was initially described as a distinct species: Vipera nikolskii [21].

Although the adder is one of the most studied snake species in the world, there are problems related to the systematization of this complex [10, 22]. A general ambiguity regarding its distribution has been created due to this problem and it has been considered that the respective taxon was endemic to Ukraine. Further research demonstrated that the range of Nikolsky’s viper was from the east to the south of Russia and towards the west of the Moldova Republic [13]. As a result of more profound studies on the systematization of the Vipera berus complex in the western part of Eastern Europe (the Western part of Ukraine, Moldova Republic and Romania) the range of Vipera [berus] nikolskii extended to the west up to the Eastern part of Romania. Thus, the populations of vipers in the area situated east from the river Siret belong to this taxon [22]. Identifying this taxon on the territory of Romania and thus on the territory of the European Union, rises problems referring to the statute and measures of conservation. Solving such problems requires the development of long term ecological studies of the populations [8, 14].

The ecology of this taxon was not adequately studied up to the present day; thus the most elementary data regarding ecological characteristics of the populations do not exist [12, 22].


1. Andersson S., (2003): Hibernation, habitat and seasonal activity in the adder, Vipera berus, north of the Arctic Circle in Sweden. Amphibia-Reptilia 24: 449-457.

2. Băcescu M., (1933): Vipera berus în Moldova şi Basarabia. Rev. Ştiinţ. “V. Adamachi”, Iaşi, 9: 3−13. [in Ro]

3. Covaciu-Marcov S.D., Sas I., Kiss A., Bogdan H., Cicort-Lucaciu A.Şt., (2006): The herpetofauna from the Teuz River hydrographic basin (Arad County, Romania). N. Wes. J. .Zool. 2 (1): 27-38.

4. Covaciu-Marcov S.D., Cicort-Lucaciu A.Ş., Dobre F., Ferenţi S., Birceanu M., Mihuţ R., Strugariu A., (2009): The herpetofauna of the Jiului Gorge National Park, Romania. North-Western Journal of Zoology 5 (Supplement 1). Ed. Universităţii din Oradea, Oradea.

5. Fuhn I. E., Vancea Şt., (1961): Fauna R.P.R.. Reptilia (Ţestoase, Şopîrle, Şerpi). Vol. XIV, fasc. 2, Ed. Academiei R.P.R., Bucureşti, 338 pp. [in Ro]

6. Fuhn I.E., (1969): Broaște, șerpi, șopârle. Ed. Ştiinţifică, Bucureşti. [in Ro]

7. Gasc J.P., Cabela A., Crnobrnja-Isailovic, Domen D., Groessenbacher K., Haffner P., Lescure J., Martens H., Marinez Rica J.P., Maurin H., Oliveira M.E., Sofianidou T.S., Veith M., Zuiderwijk A., (1997): Atlas of Amphibians and Reptiles in Europe. Societas Europaea Herpetologica & Museum National d’Histoire Naturelle Paris.

8. Hartel T.R., (2007): Studiul faunistic şi ecologic al amfibienilor din bazinul Târnavei Mari. Disertaţie pentru obţinerea titlului de doctor în Biologie. Universitatea Ovidius, Constanţa. [in Ro]

9. Iftime A., (2005): Reptilia. In: Botnariuc & Tatole (eds): Cartea Roşie a Vertebratelor din România. Ed. Acad. Române, Bucureşti. [in Ro]

10. Joger U., Fritz U., Guicking D., Kalyabina-Hauf S., Nagye Z.T., Wink M., (2007): Phylogeography of western Palaearctic reptiles – Spatial and temporal speciation patterns. Zoologischer Anzeiger. 246: 293-313.

11. Krecsák L., (2001): A keresztes vipera (Vipera berus) előfordulása Erdélyben Collegium Biologicum, 3: 25 − 30.

12. Mallow D., Ludwig D., Nilson G., (2003): True Vipers. Natural History and Toxinology of Old World Vipers. Krieger Publishing Co., Malabar, Florida.

13. Milto K.D., Zinenko O.I., (2005): Distribution and morphological variability of Vipera berus in Eastern Europe. In: Herpetologia Petropolitana: 64-73. Ananjeva N. and Tsinenko O., Eds., St. Petersburg.

14. Sas I., Covaciu-Marcov S.D., Demeter L., Cicort-Lucaciu A.Ş., Strugariu A., (2008): Distribution and status of the moor frog (Rana arvalis) in Romania. În: Glandt D. & Jehle R. (eds.): Der Moorfrosch/The moor frog. Laurenti Verlag, Bielefeld, Germany.

15. Shine R., Madsen T., (1994): Sexual dichronatism in snakes of the genus Vipera: a review and a new evolutionary hypothesis. Journal of Herpetology 28 (1): 114-117.

16. Strugariu A., Sahlean T. C., Volosciuc-Hutuleac M. V., Puscasu C. M., (2006): Preliminary data regarding the distribution of reptilian fauna in Suceava County (Romania). N. Wes. J. Zool., 2 (1): 39−43.

17. Strugariu A., Zamfirescu Şt.R., Nicoară A., Gherghel I., Sas I., Puşcaşu M.C., Bugeac T., (2008): Preliminary data regarding the distribution and status of the herpetofauna in Iaşi County (Romania). North-Western Journal of Zoology 4 (1): S1-S23.

18. Strugariu Al., Gherghel I., Nicoară A., Huţuleac-Volosciuc M. V., Moraru V., Mizeruş A., (2009): A rapid survey of the herpetological fauna from Vaslui Country (Romania) with the first record of the slow-worm (Anguis fragilis) in the region.  Herpetologica Romanica, Bulletin of The Romanian Herpetological Society, Vol. 3, pp. 25-30.

19. Ursenbacher S., Carlsson M., Helfer V. Tegelstrom H., Fumagalli L., (2006): Phylogeography and Pleistocene refugia of the adder (Vipera berus) as inferred from mitochondrial DNA sequence data. Molecular Ecology 15 (11): 3425-3437.

20. Vancea Şt., Fuhn J. E., Borcea M., (1982): L’étude morphologique des populations Vipera berus berus du Plateau Central Moldave des Carpathes Orientales et de Transylvanie. Vert. hung., 21: 245-250.

21. Vedmederja V.I., Grubant V.N., Rudaeva A.V., (1986): On the name of the black adder in woodland steppe zone of European part of USSR. Vestnik Kharkovskogo Universiteta, 288: 83–85.