A spring wildlife survey has been launched to reveal the secret lives of Norfolk's native reptiles – but how well do you know our adders, grass snakes and common lizards?

Eastern Daily Press: The grass snake is one of the three species in the Norfolk Wildlife Trust's spring reptile survey. Picture: Julian ThomasThe grass snake is one of the three species in the Norfolk Wildlife Trust's spring reptile survey. Picture: Julian Thomas (Image: Julian Thomas)

Norfolk Wildlife Trust's spotter survey aims to gather information which could help improve understanding of the elusive reptiles' distribution across the county, as they begin to emerge from hibernation in the warmer spring weather.

But here are 10 things which nature experts already know about the county's snakes and lizards.

Adder:

• Adders, like most reptiles, are shy and retiring and bites mostly occur when people or animals touch them.

Eastern Daily Press: The common lizard is one of the three species in the Norfolk Wildlife Trust's spring reptile survey. Picture: Dave KilbeyThe common lizard is one of the three species in the Norfolk Wildlife Trust's spring reptile survey. Picture: Dave Kilbey (Image: Dave Kilbey)

• There have only been twelve deaths from adder bites in the last 100 years.

• Adders do not lay eggs – instead the females retain their eggs within their body and give birth to live young.

• Adders can, and do, swim.

Common lizard:

• The female common lizard retains her eggs and gives birth to live young.

• Common lizards can flatten their body to the ground enabling them to absorb more of the sun's rays.

• Common lizards can shed their tails as a defence against predators. The tails carry on wriggling and distract the predator so the lizard can escape. A new tail will grow but it will leave a scar and will be slightly shorter than the original.

Grass snake:

• Britain's only egg-laying snake, the eggs are laid in rotting vegetable matter, including compost heaps.

• Grass snakes are very good swimmers and can stay under water for up to half an hour.

• When they are threatened, grass snakes can pretend to be dead – if this does not deter the predator, they hiss loudly and release a pungent liquid from their anal gland.

ABOUT THE REPTILE SURVEY

David North, head of people and wildlife at Norfolk Wildlife Trust, said: 'This March, April and May we are asking people to share their wildlife sightings of three amazing reptiles found in Norfolk: adder, grass snake and common lizard.

'After hibernating through the winter, reptiles begin to emerge in spring as the weather starts to warm, basking in the spring sunshine. Of course reptiles are very elusive, and often will disappear from sight before you have even seen them, so when trying to spot reptiles you have to move slowly and quietly.

'If you are lucky enough to see an adder, grass snake or common lizard please remember not to disturb them and definitely do not attempt to pick them up.'

Adders are scarce across much of East Anglia, but there are strongholds that exist along coasts and heaths. Heathland habitat has declined in Norfolk so conservationists think it is also likely that adders have declined in numbers and range.

The grass snake, our largest snake, is particularly fond of wetland habitats, but can also be found in dry grasslands and in gardens, especially those with a pond nearby. It is usually greenish in colour, with a yellow and black collar, pale belly, and dark markings down the sides.

The common lizard is found across many different habitats in Norfolk including heathland, woodland and grassland. It is the UK's most common and widespread reptile, and on of two species of lizard found in Norfolk, the other being the slow worm.

Sightings can be submitted via the Norfolk Wildlife Trust website, which also contains a distribution map of all the sightings so far, or by calling Norfolk's Wildlife Information Service on 01603 598 333.