Just how common is the common lizard? A survey aims to find out - and to see if the habitats of Ireland's only native reptile are under threat, reports Yvonne Cunningham
They've been here since the Ice Age but many people are surprised when they meet a lizard basking in the Irish sun.
The common lizard (Lacerta vivipara) is the only reptile native to Ireland and the Irish Wildlife Trust is carrying out a survey to see just how common the common lizard is.
"The purpose of the survey is to determine how widespread they are and to start investigating if there are any possible threats to their habitats, particularly in coastal sand dunes and areas like that," says Sean Meehan, a volunteer at the Irish Wildlife Trust.
"We're asking members of the public to let us know if they see a lizard anywhere," he adds.
Lizards seem to favour coastal areas, but have been sighted in every county in Ireland. "We've had reports from beaches, mountains, woodlands and people's gardens. We've had reports from gardens and car parks in towns and cities, so it would appear that they can be found anywhere there is a suitable habitat, stony ground to bask on and grass for hunting insects," says Meehan.
The common lizard has had to make a few adaptations to be able to live in our cool climate. "Unlike most other reptiles, they don't lay eggs and incubate them. The female gives birth to live young. That's a climatic adaptation - its very difficult for a reptile to keep eggs warm and to get them to hatch," says Meehan.
The lizard also hibernates for the winter months. "It appears that in December, January and February they hibernate. The earliest sightings we've had are mid-February, so we could say they hibernate for the Christmas period," says Meehan.
Climate change may be affecting the lizard's hibernation patterns. "Because of the recent spell of milder-than-average winters, they been seen out and about during a spell of very mild weather in the winter," says Meehan.
"It could be interesting to see if there is a trend developing with climate change - as winters become milder will they hibernate less and less? But that's a long-term project - at the moment they do hibernate for the winter."
It is difficult to tell if the Irish lizard population is changing. "The last survey, published in 2005, showed over 200 sightings. It looks like we will better that figure this year - in the last week alone we've had over 20 sightings," says Meehan.
"Although they are rarely seen, they seem to be a fairly steady population. It would take a number of surveys over a number of years to determine whether they are actually decreasing or increasing. It would be something that we would be keeping an eye on," he adds.
Lizards are cold-blooded - they have no way of regulating their own body temperature. That means that the best time to spot a lizard is on a sunny summer morning. "They are mostly observed basking out on a rock or a log to absorb the sun's heat and the heat off the stone as well. Once their body temperature reaches a certain level they become active and have the energy to hunt," says Meehan.
"If we get very hot weather, during the hottest part of the day they seek shade - they have no way of regulating their body temperature so they have to seek a bit of cool again."
Lizards have many predators, which makes them wary of people. "They are so rarely spotted because when they are out basking, as soon as they see a shadow or hear anything they are gone," says Meehan.
Birds of prey will eat lizards, as will foxes and stoats. The domestic cat is another predator. "We get a lot of reports from people who have told us that their cats have carried in lizards."
If a lizard is caught by a predator, he has a unique escape mechanism. "They snap their tails off. Say a cat grabs a lizard by the tail, the lizard starts wriggling and the tail will be left in the cat's mouth, the lizard will have escaped," says Meehan.
"The lizard will grow a new tail over the next couple of months. Sometimes we get photographs of lizards and their tails are different colours to the rest of their body."
The National Common Lizard Survey is being funded by the National Parks and Wildlife Service. Sightings of lizards can be reported by filling out a form on the Irish Wildlife Trust's website www.iwt.ie or by e-mailing lizard@iwt.ie