Viviparous Lizard / Common Lizard (Zootoca vivipara).
Here in the UK there are three native lizard species and a further two non-native species that have well established breeding colonies in certain parts of the UK.
The Viviparous (Common) Lizard
Slow Worm (leg-less lizard)
Viviparous Lizards are fairly small reaching a maximum length of 150mm including full tail. They are notably smaller than our other native lizard the Sand Lizard.
Male Viviparous Lizards have bright orange or bright yellow undersides with many black spots. These colours are clearly visible during the breeding season.
The female usually has a plain pale creamy-yellow coloured underside with no or very few spots.
The most accurate way to sex the Viviparous Lizard is to look for the hemi-penal bulge present on all males at the base of the tail. Males have larger heads and longer tails. Females tend to have longer bodies and smaller heads.
Patterning can also aid sexual identification but is not always accurate. Males tend to have rows of spots and females tend to have unbroken lines running the length of their backs.
These active lizards can be found in varying shades of brown, ginger and dark green. Melanistic examples are also found across the country on occasion.
They are quite a hardy species and are usually the first and the last reptiles to be seen in the UK. I saw my first Viviparous Lizard of 2012 on January 2nd showing how quick they are to emerge from hibernation on even the mildest of days.
The Viviparous Lizard is the only native reptile found in Ireland and it is also the only native reptile on the Isle of Man.
The broken pattern on this male Common Lizard's tail shows that the lizard has 'dropped' its tail at some point to evade capture from a predator. The tail has re-grown well in this case. This a defence mechanism adopted by all the lizards found in the UK.
This cumbersome gravid female gave birth to ten young shortly after this photo was taken. It is rare for these lizards to give birth to more young than this. A clutch of 5-9 is more usually the case. The word "viviparous" means to give birth to live young that are fully developed within the adult females body prior to birth. The female Common Lizards give birth to live young. They do not lay eggs. They are born encased in a thin membrane which the young lizards quickly free themselves from.
This juvenile Viviparous Lizard is just a few days old and is already totally independent and hunting food for itself. Juveniles are usually very dark brown in colour. They tend to have an almost metallic bronze appearance.
Viviparous Lizards are quite brave and will often bask quite openly and return to the same basking spot as quickly as 10 minutes after being disturbed and scared off.
Viviparous Lizards are often found in small groups. These two juveniles have not yet developed their full adult colouration. The young lizard in the foreground of this photo has dropped it's tail to avoid being caught by a predator which was most likely a corvid or a domestic cat.
One of 23 Viviparous Lizards I recorded on this grassland site in Kent on a warm sunny morning 2014. Most were seen basking on logs, rock-piles or in the grass. A couple were found under refugia.
This dumped sheet of corrugated iron quickly absorbed the sun's rays and made an ideal basking spot for this male Viviparous Lizard.
Sand Lizard (Lacerta agilis)
Sand Lizards are the UK's rarest native lizard and are fully protected by UK law. They are restricted to just a few places across England and can be found in Dorset, Hampshire, West Sussex and Surrey on heathland at dune sites. There is also an isolated population resident at the Lancashire coast at Sefton. This northern population varies slightly in appearance. There have recently been reintroductions of Sand Lizards at several sites including one at the Talacre Dunes in Wales as part the captive bred release programs by ARC-Trust and Chester Zoo.
Sand Lizards are larger and stockier than than our Common Lizards and can grow to around 20cm in length. Despite the latter part of their scientific name "agilis" these lizards are not as fast or agile as their smaller, slimmer and longer-legged cousins the Common Lizard. There are strong visual differences between male and female Sand Lizards during the mating season (April/May). The males usually have bright green markings along their flanks. Out of the mating season the two sexes are harder to tell apart. The green markings are much less obvious but males are stockier in build and have larger heads. The eye of the male sits only about a third of the way along its head (nearer the neck) but the female's eye sits about half way along the head.
This young adult male Sand Lizard basks on a log pile built as part of the excellent land management at a heathland reptile site in Surrey. It was photographed during May when the males exhibit their mating colours with the vivid green sides of their head and body.
Sand Lizard eggs are laid in clutches of 2-16 usually around end of May or the start of June. They are laid in soft sand that is exposed to the sun and they rely entirely on the warmth of the sun for them to hatch. In poor summers this may result in very few if any successfully hatching. The juveniles are left to fend for themselves and will prey on small insects. They have two long light dorsal stripes along their backs and a row of spots along their flanks and look similar to adult females. Juvenile Sand Lizards look vastly different to juvenile Common Lizards which are very dark in appearance and do not possess any of the Sand Lizards markings.
The Slow Worm (Anguis fragilis).
Slow Worms (also known as Blind Worms) are neither slow, nor blind, nor a worm. Neither are they a snake. They are in fact a limbless lizard. They are a welcome visitor to any garden as they are carnivorous and feed mainly on slugs and snails. They can be distinguished from snakes by the presence of eyelids. Snakes do not have eyelids but a Slow Worm will blink if you watch it carefully. Slow Worms can grow to 30-40cm in length and occasionally up to 45cm. The largest ever found in the UK had a total body length in excess of 50cm. It was recorded and photographed on the Steep Holm Island in Somerset. The photos are publicly displayed at the visitors centre there.
As Slow Worms grow older their colour tends to fade especially with males. Occasionally old male Slow Worms can develop bright blue spots along their back.
Another ageing male Slow Worm starting to develop blue spots on its back.
Melanism is the increase of the black pigment 'melanin' in the skin of animals. It is the opposite of albinism. All reptile species can produce melanistic examples. In some species this is considered extremely rare whilst in others it is fairly common. This partially Melanistic Slow Worm is the first I have seen and melanism in Slow Worms is considered very uncommon.
Juvenile Slow Worms like the one pictured above, have dark flanks and a dark vertebral (back) stripe. These markings usually remain as female Slow Worms mature but males will lose them and become much more uniform in colour.
Taken in April 2016, this juvenile Slow Worm is one of last year's young and still measures just 9cm in length. The £1 coin has been placed to give an idea of scale.
This adult female Slow Worm was found slithering over damp autumn leaves at the edge of dense woodland. The Slow Worm was living up to its name and was struggling to remain very active with the cool mid-October air temperature of just 11 degrees, a cloudy sky and very little sunlight.
Slow Worms have very small flat unkeeled scales giving them a very smooth shiny appearance. When newly sloughed Slow Worms can look as though they're made of glass.
Common Wall Lizard (aka European Wall Lizard) (Podarcis muralis).
The Wall Lizard is a non-indigenous species found in the UK and is thought to have originated from several deliberate and accidental introductions from Europe. They are slightly larger than the Common Lizard growing to a maximum length of 180-200mm including the long tail. They have a longer and more pointed face than the Common Lizard too. The males sometimes exhibit brightly coloured green or yellow backs. Wall Lizards can show huge variation in colour within the same colony. They have established healthy breeding colonies on a few coastal towns across the south of England with the largest populations being found in the Bournemouth area. There is even a colony in SE London. They have also been recorded in smaller numbers at many other sites across the UK suggesting multiple releases via the reptile trade. The Wall Lizard is also found across the island of Jersey where they are native to the island and are afforded legal protection.
Females tend to lay clutches of 2-12 eggs in thick vegetation, holes in the ground or underneath rocks. The eggs usually hatch around 5-7 weeks later in July. They are thought to live for around 10 years. They can be found in very dense populations of huge numbers on any one site if the conditions are just right for them. Wall Lizards in the UK are often seen well into October before hibernating. They will often emerge in mid-winter to bask if the sun comes out for long enough and have been seen basking in both December and January on occasion. Wall Lizards are very fast-moving and highly agile and can leap to catch all manor of insect prey. They often thrash their prey once caught against rocks before swallowing it head first.
Juvenile Wall Lizards often have the same bronze metallic appearance of the juvenile Viviparous Lizard but they are not as dark in colouration. Young Wall Lizards are prey for many species including on occasion larger Wall Lizards. This is a link to one example where cannibalism has been recorded within this species: Click here
These Wall Lizards are a colouful addition to our coastal cliffs where they occupy a habitat unsuitable for our own native herps. They are not so welcome at other sites though where their speed, agility and aggression makes them likely to out-compete our native Sand Lizards and Viviparous Lizards. Because of this there have been other sites in the UK where Natural England have responded quickly in removing an introduced population of Wall Lizards before they've had a chance to spread beyond control.
The Western Green Lizard (Lacerta bilineata).
The Western Green Lizard is a very brightly coloured green lizard and is only found in a couple of specific locations in the Bournemouth area of Dorset along the south coast of England. They are considerably longer and stockier than other lizards found in the UK growing up to 150mm long or 400mm including the tail. The males are usually more colourful and some exhibit a blue throat and lower face parts especially during the mating season in the spring. It is widely accepted that these lizards have been introduced to England following deliberate or accidental release of captive specimens from the reptile trade. It is highly likely that there have been numerous releases in the area. The earliest reports of these lizards in Bournemouth dates back as far as the 1970's but confirmation of Western Green Lizards being present wasn't until the 1990's.
In 2011 these lizards were doing well in Boscombe near Bournemouth, Dorset however numbers have declined significantly recently due partly to the very poor summers and harsh winters of 2011 and 2012. Because of their beautiful appearance they have also have been victims of collectors for the reptile pet trade. Another reason for their decline is predation from a pair of resident Kestrels that have been seen searching for and feeding on the Western Green Lizards on the cliffs. Bournemouth Borough Council promote these "exotic lizards" as a tourist attraction to the area: Bournemouth Council Website
The Western Green Lizard is also found across much of the island of Jersey especially in the SW where they have a stronghold. On Jersey these specimens are totally native to the island where they are afforded full legal protection.
The adult females often retain the juvenile stripes running the length of their backs and tail. Adult males lose these stripes and have more obvious blue colouration to the throat.