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Viviparous lizards typically communicate through olfactory signals. They have femoral pores (on their thigh) that secrete hormones that act as chemical cues. The chemical signals produced by males are cues to females regarding their suitability for reproduction and competitive ability.
Viviparous lizards are able to perceive their environment through visual, auditory, olfactory, and vibrational cues.
Communication Channels: visual ; chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical
Viviparous lizard populationss are considered stable, but the species is protected in some countries within its range (e.g. Switzerland). Many of the areas in which it occurs are also protected.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Viviparous lizards are the only lizard species that is known both to give live birth and to lay eggs. The reasons for differences in reproductive method between indiviudals or entire subpopulatons has yet to be discovered. When lizards are placed in multiple environments, females bear their young in different ways.
When the young are born live, they do not all arrive at the same time, with the first and last individuals being born a few days to a week apart. In oviparous individuals, the development of the egg takes around 3 months to complete. Individual sexes are not determined until sexual maturity.
Development - Life Cycle: indeterminate growth
Their are no known negative effects of viviparous lizards on humans.
Due to their rare reproductive qualities, viviparous lizards are of great research interest.
Positive Impacts: research and education
Viviparous lizards are secondary consumers that prey on smaller insects and other arthropods, and are also a source of food to larger predators such as snakes, dogs and cats. They are hosts to protozoal parasites in the genera Haemogregarina and Plasmodium, an external parasitic mite. These parasites affect the immune system of the lizards and decrease energy reserves. Heavy infections may sometimes result in death.
Commensal/Parasitic Species:
Food consumption is regulated by a lizard’s internal temperature. In the wild, this species ceases feeding when its internal temperature is less than 27°C. Captive lizards, can feed when their internal temperatures are lower, but must have time for acclimatization. These lizards feed on invertebrates, focusing on hemipterans (e.g., cicadas), spiders, and mealworms. Sometimes they also feed on moth larvae.
Animal Foods: insects; terrestrial non-insect arthropods
Primary Diet: carnivore (Insectivore )
Viviparous lizards are found throughout Europe and northern Asia, including China and Japan, with a north to south range extending from Italy to northern Russia. It is the only lizard species found in Ireland.
Biogeographic Regions: palearctic (Native )
Viviparous lizards have the ability to acclimate to a range of climates and elevations. This species lives in a variety of habitats, including peat bogs, heathlands, meadows, and dunes. They also tend to be found around bodies of water such as lakes or streams.
Range elevation: 0 to 3,000 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: desert or dune ; savanna or grassland
Wetlands: marsh ; swamp ; bog
Other Habitat Features: riparian
The average lifespan of viviparous lizards is 5 to 6 years. Most mortality is from natural causes, rather than predation. There have been three documented cases of individuals living up to 8 years. In captivity, the lifespan of these lizards is 4 to 6 years.
Range lifespan
Status: wild: 8 (high) years.
Range lifespan
Status: captivity: 6 (high) years.
Typical lifespan
Status: wild: 5 to 6 years.
Typical lifespan
Status: captivity: 4 to 6 years.
Viviparous lizards have a wide color range, varying between brown, red, grey, green, or black. This species displays sexual dimorphic color patterns on its underside, with males being brightly colored in yellows, blues, oranges, and greens. Males are also easily identified by having white spots in a longitudinal arrangement on their dorsal side. The base of the tail in sexually mature males is also noticeably thicker than in females. Sexually mature adults of both sexes typically weigh between 2 to 5 g, with total lengths of 50 to 77 mm.
Average mass: 2-5 g.
Average length: 50-70 mm.
Other Physical Features: heterothermic
Sexual Dimorphism: sexes colored or patterned differently; male more colorful
The most common predators of this species are snakes. Additionally, hedgehogs, shrews, domestic dogs, and domestic and feral cats will eat juvenile lizards.
Known Predators:
Anti-predator Adaptations: cryptic
Male viviparous lizards must shed their skin before mating, which generally occurs in April. Before males shed, they show very little reproductive interest in females. The female lizards also shed, buty do not attempt to engage males in reproduction. When choosing a mate, males base the decision on the female’s skin color. The duller the female's color, the higher the chance of mating and survival of young, due to the better camouflaging of more drably colored females. Males typically engage in mating within 30 seconds of meeting a female. Mating behavior is initiated by males biting the female’s head, and then copulating with her several times over the course of 5 to 30 minutes. Females exhibit aggressive behavior if they do not wish to mate, snapping their jaws, biting fiercely, and running away from undesirable males. Both males and females have multiple mates.
Mating System: polygynandrous (promiscuous)
Viviparous lizards reach sexual maturity at approximately 2 years of age, with females tending to mature more slowly than males. Although oviparous females lay 7 to 70 undeveloped eggs, only 5 to 8 typically survive, with similar numbers of offspring being produced by oviparous and viviparous individuals. After the eggs are laid, they are typically hidden in vegetated areas close to water. Development takes approximately 3 months to complete. In the wild, newly born lizards reach independence one day after birth, after breaking out of the egg membrane in which they are born. In captivity, lizards achieved independence in 1 to 6 days.
Breeding interval: Viviaporus lizards breed once a year.
Breeding season: Copulation occurs in April or May. Eggs (or live young) are typically produced in July.
Range number of offspring: 4 to 8.
Average number of offspring: 5.
Average gestation period: 3 months.
Range time to independence: 1 to 6 days.
Average time to independence: 4 days.
Average age at sexual or reproductive maturity (female): 24 months.
Average age at sexual or reproductive maturity (male): 22 months.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization ; viviparous ; oviparous
While viviparous females do offer protection to developing young by harboring them inside their body, viviparous lizards have no involvement in raising their young. Although the young lizards do not interact with either parent, they can identify their mother’s scent throughout their life.
Parental Investment: female parental care ; pre-hatching/birth (Protecting: Female)
