Since I have been on holiday in the South of France I have seen one animal more than any other (apart from flies) and yet I can never tire of watching them. The common wall lizard is an awesome, agile, charismatic reptile full of character and a sight I will surely miss when I return to England. Due to their commonness and quirkiness I thought I’d do a profile about their biology and behaviour.
A familiar sight across Europe, the common wall lizard (Podarcis muralis – muralis being Latin for wall) is often seen basking on a stone wall, darting into a crevice or leaping to catch a fly. They’re a medium lizard rarely exceeding 20 cm with an elongated appearance.
Despite being incredibly varied in colour P.muralis isn’t particularly difficult to identify. From a distance they can sometimes be misidentified as a viviparous lizard (Lacerta vivipara), due to similar colouring, however P.muralis is a far more wiry lizard with a slim body supporting a longer and more pointed head. Another distinguishing feature is the row of blue scales frequently, but not always, found along the lower flanks of the wall lizard. Their eyes and rounded snout are set high on the head resulting in them resembling a small alligator. While being highly varied in colouration (making them very difficult to describe), they frequently have a dark coloured band extending from their snout along the length of their bodies with a mottled pattern along their back. Generally they are a brown or grey colour, sometimes with a hint of red, however they can also be green, this is more common in males.
Habitat and distribution
Naturally saxicolous (lives amongst rocks) P.muralis prefers open, sunny areas and stone walls – funny that! They are frequently found around houses, quarries and roadsides, favouring areas with sparse vegetation providing them with plenty of areas to bask in. Some foliage is still required to support the food chain of invertebrates. Stone walls and rockeries provide a perfect habitat as there are a plethora of crevices to take refuge in but also loose stones at the base which can be used for egg laying.
They are widely distributed across mainland Europe, ranging from Northern Spain through to Northern France. For the most part they are absent in Northern Europe but do occur in patchy, isolated populations. There are around 20 separate colonies in the UK, however the only native populations in the British Isles are on the channel island of Jersey. Globally they have been introduced in a variety of areas including the US.
Podarcis muralis is a diurnal lizard and a lover of sunshine. Most commonly seen basking on rocky surfaces, they flatten their body to increase their surface area and maximise heat absorption from both above and below. Leg waving is a frequently observed behaviour, this is done to either greet another P.muralis or to submit to a larger animal (such as an observing human). They move using quick bursts of running with intermittent pauses, these pauses are thought to allow them to spot predators or prey. Interestingly studies show that they alter their burst speed and frequency of pauses depending on the presence of predators, the distance to the predator and the distance to a place of refuge.
As far as food is concerned they are insectivores and are proficient at catching a myriad of invertebrates, including: crickets, grasshoppers, spiders and caterpillars. They are also able to catch flying insects by launching themselves from a perch. Once a prey item has been caught, the lizard will whip its head from side to side to subdue the item. They consume the meal head first and then proceed to wipe their jaws along the ground removing any debris.
Hibernation and mating
Hibernation begins in November and ends in March/April although during warmer weather hibernation can be interrupted. Breeding then commences immediately after hibernation and starts with displays, and sometimes battles, between the males. There is little courtship between the male and female. Females will lay between 2 and 10 eggs up to three times a season which are laid in soft soil or under rocks. Around 2 months later the eggs will hatch and the juveniles will emerge as miniature versions of adults. The young are completely independent from birth and will reach sexual maturity in 1-2 years. They have an average life expectancy of 7 years, but can live for up to 10 years. Due to their fast maturity, number of eggs and frequency of egg laying P.muralis often out breeds native lizards in areas where it has been introduced.
The common wall lizard is a fascinating animal and one that I have greatly enjoyed observing, photographing and studying. I am now very used to seeing them scurry up walls, leaping after prey and darting away from me as I walk and will be sorry to leave these quirky little companions.
A slightly longer post than I intended but I had a lot to say about them, I’ll try to ensure that not all the posts are this long.
This information has been gathered from a variety of sources (see below) and my own observations.