Viviparous Lizard
Zootoca vivipara (von Jacquin, 1787)

Family: Lacertidae - Rock & Wall Lizards

Order: Squamata (Sauria) - Lizards

Class: Reptilia

Phylum: Chordata - Vertebrates

Kingdom: Animalia

Red List status: Lower Risk/least concern

Viviparous lizard. Lincolnshire, United Kingdom.

Snout-vent length: 65 mm

Total length: Up to 170 mm

 

Hatchling total length: 15-35 mm

RANGE

The most widespread European member of its family, the viviparous lizard occurs trough northern Europe and Asia, from Ireland in the west to the Asian Pacific Coast in the east. Populations occur as far north as the Arctic Circle, and south into the Balkans, north Italy and northern Spain. The species is most abundant in the north of its range.

            Range            Description            Habitat            Behaviour            Biology            Taxonomy            References
Other common names: Common lizard

 

DESCRIPTION

A long-bodied, moderately robust lizard with short legs and a well-developed neck and tail (the latter 1.3-2 times as long as the head and body). The lizard has a somewhat rounded appearance, and a blunt, rounded snout. Females have smaller heads and shorter legs than males. Scales are large and distinct; 25-37 occur across the dorsum at mid-body. The scales of the back are normally keeled. There are no more than four, and usually no, granular scales between the scales at the top of the eye orbit (supraoculars) and the supraciliaries.

Male viviparous lizard, clearly showing the broken dorsal stripe. Note the keeled scales of the back.

 

 

Animals are generally brown or grey to olive. Patterning may be indistinct; when present, there are usually dark bands along the side of the body and lighter longitudinal streaks may also be present. A mid-dorsal stripe is commonly present in females, but is absent or not continuous in males. In males, the back is often darker than the flanks. Ocelli may occur over the dorsum and flanks in both sexes, but are typically better-developed in males. Animals can exhibit great variability in the extent and type of patterning even within a singlepopulation. In most male and some female common lizards, numerous dark spots occur on the ventral surface, which ranges in colour from white to orange or red. The throat is white or blue. Young may be very dark in colour.

Male viviparous lizard. Note the patterning on the underside.

 

Similar species: Through most of the common lizard's European range, the most similar co-occurring species is the European wall lizard (Podarcis muralis), which may resemble it in patterning and colouration. The wall lizard attains a slightly larger adult size, has proportionately longer legs and a larger head, and appears somewhat flattened (rather than rounded). This species typically has five or more granules between the supraoculars and the supraciliary scales, and 42-75 scales across the dorsum at mid-body. The collar (a row of scales on the underside of the head at the base of the neck) is serrated in the viviparous lizard,  but smooth in the wall lizard. The sand lizard (Lacerta agilis) is larger and more robust, and has a deeper, shorter head; males also attain green colouration on the flanks and limbs when in breeding condition, never present in the common lizard (although some specimens of Z. vivipara may exhibit iridescence which appears greenish from some angles). Patterning differs between the two species, and the sand lizard may have a greenish underside. The sand lizard may be patterned dorsally with dark blotches with a white spot in the centre of each, a pattern combination never found in Z. vivipara. In the Balkans there may be some overlap with the meadow lizard (Z. praticola); this species never has a spotted underside. Viviparous lizards can be distinguished from four-limbed skinks by their more robust, less elongated bodies and more coarsely-scaled appearance.

 

HABITAT

Terrestrial in areas with grass cover or other short vegetation, particularly favouring humid areas. Otherwise this a species of varied habitats, from high-altitude alpine meadows to marshland, woodland edges (and sometimes open woodland), heath and sand dunes. The species is tolerant to a degree of habitat disturbance, and may use artificial habitats including railway embankments and, occasionally, gardens.

Elevation: 0-2,500 m

 

BEHAVIOUR

An active diurnal reptile, the viviparous lizard basks frequently, and may alternate basking and foraging behaviour. Animals may forage by both sight and sound, having an acute sense of hearing. Favoured basking spots may be revisited over several days. The viviparous lizard, which ranges further north than any other lizard, is well-adapted to cool conditions and may be active from as early as February until as late as November in Britain. The lizards are strong swimmers, and may enter water both to hunt prey and to evade predators. Animals have been observed climbing into vegetation and up walls, although the species is primarily terrestrial.

Diet: Insects, small spiders and earthworms. Feeding lizards may remove the wings of insect prey before consuming it.

 

BIOLOGY

Breeding biology: Unusually for lacertid lizards, the viviparous lizard gives birth to litters of between 5 and 12 live young in most of its range; young are born 6-13 weeks after mating. Southern populations in Spain and France lay clutches of up to 13 (typically 5-7) eggs up to 12 x 10 mm. Animals become sexually mature at 1-2 years of age.

Lifespan: Up to 12 years in the wild.

 

TAXONOMY

Long-known as Lacerta vivipara, a name still found in older field guides. The subspecies Z. v. pannonica is recognised from Austria and Hungary, and is separately listed by the IUCN as Vulnerable (European Reptile & Amphibian Specialist Group, 1996).

 

REFERENCES

Arnold, N. and Ovenden, D. (2004) Collins Field Guide: Reptiles and Amphibians of Britain and Europe HarperCollins, London: 288pp

European Reptile & Amphibian Specialist Group 1996. Zootoca vivipara ssp. pannonica. In: IUCN 2008. 2008 IUCN Red List of Threatened Species.

Wareham, D.C. (2008) The Reptiles and Amphibians of Dorset British Herpetological Society: 120pp

Zootoca vivipara, Buckinghamshire, United Kingdom. Note details of the scalation, especially the absence of granules between the supraciliary scales and the scales of the eye orbit (supraoculars).