Viviparous lizard

The viviparous lizard or common lizard (Zootoca vivipara, formerly Lacerta

Lacerta (genus)

Lacerta is a genus of lizards of the family Lacertidae. It is fairly diverse containing around 40 species.-Classification:Genus Lacerta*Sand lizard *Anatolian Rock Lizard...

 vivipara) is a Eurasian lizard

Lizard

Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...

. It lives farther north than any other reptile species, and most populations are viviparous (giving birth to live young), rather than laying eggs as most other lizards do.

Identification

The length of the body is less than 12 centimetres (4.7 in) (excluding the tail). The tail is 1.25 to 2 times longer than the body, although it is often partially or wholly lost. The limbs are short, and the head is rather round. Males have more slender bodies than females. The neck and the tail are thick. The collar and other scales seem jagged.

The colour and patterning of this species is remarkably variable. The main colour is typically mid-brown, but it can be also grey, olive brown or black. Females may have dark stripes on their flanks and down the middle of the back. Sometimes females also have light-coloured stripes, or dark and light spots along the sides of the back. Most males and some females have dark spots in their undersides. Males have brightly coloured undersides – typically yellow or orange, but more rarely red. Females have paler, whitish underparts. The throat is white, sometimes blue.

Range

The viviparous lizard is widely distributed throughout Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

. Its range extends to the north of the Arctic Circle

Arctic Circle

The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....

. It ranges from Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 to Hokkaidō

Hokkaido

, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...

 and Sakhalin

Sakhalin

Sakhalin or Saghalien, is a large island in the North Pacific, lying between 45°50' and 54°24' N.It is part of Russia, and is Russia's largest island, and is administered as part of Sakhalin Oblast...

. It is absent from most of the Mediterranean area, although it occurs in northern Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

, northern Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, Serbia

Serbia

Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...

, Republic of Macedonia

Republic of Macedonia

Macedonia , officially the Republic of Macedonia , is a country located in the central Balkan peninsula in Southeast Europe. It is one of the successor states of the former Yugoslavia, from which it declared independence in 1991...

 and Bulgaria

Bulgaria

Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...

. It is also absent from the area surrounding the Black Sea

Black Sea

The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...

.

In the southern parts of its distribution range the species lives at high elevations, occurring as high as 3,000 metres in the Alps

Alps

The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....

. In these areas the viviparous lizard lives in damp places or near water, including meadows, swamps, rice fields, by brooks and in damp forests. In the northern part of the range the species is also found in lowlands, where it occurs in drier environments, including open woodland, meadows, moorland, heathland

Lowland heath

Lowland Heath is a Biodiversity Action Plan Habitat as it is an ancient wild landscape type. Natural England's Environmental Stewardship scheme describes it as containing dry heath, wet heath and valley mire communities, usually below 250 metres, on acidic soils and shallow peat, typically...

, fens, dunes, rocks, roadsides, hedgerows and gardens. It lives mainly on the ground, although it may climb onto rocks, logs and low-growing vegetation.

Behaviour

The viviparous lizard feeds on invertebrates, mostly small insects. It shakes larger prey in its jaws before chewing it and swallowing it whole. In early spring, late autumn, and cool summer days it basks in the sun to reach its optimum body temperature, which is about 30°C.

The lizard mates in April or May. Males take females in their jaws before mating – if the female is not interested, she will bite the male fiercely. The offspring develops for approximately three months inside the female.

The name of the species is derived from its ability to give birth to live young, an adaptation to a cool climate – but some southern populations are oviparous (egg-laying). The 3-10 young (or eggs) are usually produced in July. The blackish young measure about 3 cm, and when first born are surrounded by egg membrane, from which they break free after about a day. Males reach sexual maturity at two years old, females at three years old. Individuals from viviparous and oviparous populations may be hybridised, but with significant embryonic malformation (Heulin et al. 1989).

In northern regions viviparous lizards begin hibernation

Hibernation

Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...

in September or October, underground or in log piles. Hibernation ends about mid-February. Further south the species is active throughout the year.