Amphibians and reptiles FAQs

Of the four species of reptile occurring in Norfolk, only the grass snake and slow worm are likely visitors to your garden. The other two species, the adder and common lizard, are creatures of more open and undisturbed habitat such as heathland, and only visit gardens rarely. 

If you wish to attract slow worms or grass snakes, you will need to keep some areas of your garden undisturbed and uncultivated. Unkempt areas of long grass, wild areas of scrub and hedgerow with plenty of undergrowth, and other nooks and crannies such as log piles, would be ideal. A compost heap is particularly useful since both slow worms and grass snakes will inhabit these either to feed on the abundant slugs and worms or to lay their eggs. A garden pond is also of great value to grass snakes because it provides an ideal habitat for them to hunt frogs and newts. 

If you are lucky enough to see any reptiles in your garden, you should report sightings to Norfolk Biodiversity Information Service so they can monitor distribution and population trends. 

The best way to see reptiles in Norfolk is to join one of the special guided walks organised by Norfolk Wildlife Trust. These guided walks will take you to the best sites for reptile spotting within the county and our experts will be on hand. 

Other sites that are rich in reptiles include the heathland areas of north and north-west Norfolk, including our Roydon Common reserve, the dune systems of north-east Norfolk between Waxham and Horsey, and our Broadland reserves at Ranworth Broad, Hickling and Upton Fen. 

Four of the six UK reptiles occur in Norfolk – the exceptions being the smooth snake and the sand lizard, which are largely confined to the heathlands of southern Britain. 

The reptiles you can see in Norfolk are: 

Adder: The adder is a quite common species in Norfolk and can sometimes be seen in areas of heathland, dune systems or woodland glades, especially during early spring when they are reviving from their winter hibernation or engaged in courtship. 

Grass snake: The grass snake is usually found on or near wetlands where they will hunt for frogs, newts and other such prey. Broadland has a large population and the best time to see them is on warm days in early spring. 

Slow worm: These ‘legless lizards’ are not very common in Norfolk. They do occupy a variety of habitats but prefer grassy meadows, woodland margins and open fields. They can also sometimes be found in gardens. 

Common (or viviparous) lizard: These reptiles are very common and widespread in Norfolk. The best time to look for one is on sunny days when they may be basking on fence posts and other exposed objects. 

A truly amphibian-friendly pond would not contain any fish. Fish like to eat amphibian larvae. However, fish will not eat toadlets as they contain a toxin in their skin, so fish and toads can live together.

It is quite common for some tadpoles to develop more slowly than others in the same pond. This may occur in small ponds with lots of tadpoles due to competition or it can happen when the water is cool (due to a cold spring or too much shade from trees) or when it contains little food, for example in new ponds where there is not yet any algae. Sometimes the tadpoles will continue to grow over winter then emerge the following year. It is also usual for some tadpoles to develop and leave the pond without being noticed, leaving the slow developers behind. Occasionally individual tadpoles will fail to go through metamorphosis (the process of turning into a frog) and remain tadpoles for their entire short life.

Several frogs will often lay their spawn together in one place and it might appear that too much has been laid. Each pond can support a certain number of frogs, depending on the quality of the habitat. In any case, most spawn and tadpoles perish so only a tiny fraction of the eggs you see in spring will naturally survive to become adult frogs. Most amphibian populations fluctuate over time, so your frog population will probably decrease in size in future years, quite naturally. There is no need to regulate the population by removing spawn. And never, under any circumstance, move spawn to ponds on nature reserves or other natural sites – this can spread invasive plants and amphibian diseases. 

The speed of development in tadpoles can vary greatly depending on environmental conditions, however it typically takes a tadpole around 14 weeks from hatching to turn into a small frog. Their back legs will emerge after a few weeks, followed by the front legs. Most tadpoles will turn into frogs by June or July.

This is actually quite common due to the tadpoles from the spring/summer missing the trigger for metamorphism (when they turn into frogs). This could be due to a lack of available food or the water temperature of the pond affecting their development rate – the lower the temperature, the slower the development. A problem for many ponds is a lack of sunlight, this could be due to overhanging trees. Sometimes carefully pruning can let more sunlight into the pond which in turn will help the pond’s flora and fauna. 

There is no need to worry about the tadpoles as they can actually ‘overwinter’ (survive through winter) in the pond. Once the temperatures increase the following year, metamorphism will take place. 

Common frogs have a moist, smooth skin which can vary in colour, ranging from brown, green or grey with dark blotches, to yellowish or orange with red blotches. However, all common frogs have a distinct brown patch behind each eye which is not present in common toads. Common toads are far less variable and are usually a mottled mid-brown colour with a granular or warty appearance. 

Another useful feature is to look at the nose. The common frog’s nose will be pointed whereas that of the common toad will be blunt, giving a much more rounded profile. Their movements also vary – common frogs tend to leap, and common toads tend to waddle or crawl. 

During the breeding season male common frogs make a quiet, low-pitched call and inhabit ponds and ditches with shallow edges. Whereas common toads make a louder, higher croak and favour deeper water. Frogspawn is laid in familiar jelly-like clumps, while toads lay long, gelatinous ‘strings’.  

Frog and toad tadpoles can also be told apart: frog tadpoles are mottled brown-grey to olive with gold speckles, while toad tadpoles remain jet black. 

Frog’s spawn is laid in big jelly-like clumps, usually in the shallow margins of ponds and ditches. Toad’s spawn is laid in long gelatinous ribbons, each with a double row of eggs, usually amongst plants.

The natterjack toad is one of the rarest of Britain’s seven native amphibians. It may be found living in coastal sand dunes, coastal grazing marshes, and sandy heaths. It can be distinguished from a common toad by the yellow stripe which runs along its back. It also differs from the common toad by having shorter legs and preferring to run rather than hop or walk.

Unlike frogs, toads tend to remain loyal to a relatively small number of traditional breeding ponds and have an instinctive desire to return to the pond in which they were born. In many areas this prevents them from using garden ponds for breeding. It is estimated that for every ‘toad pond’ there are six ‘frog ponds’. You may have toads in your garden pond during the summer months, but they are probably simply cooling off and may not stay long.

Toads tend to remain loyal to a relatively small number of traditional breeding ponds and have an instinctive desire to return to the pond in which they were born. This is why in late winter or early spring you can sometimes see mass crossings of toads on roads at night. 

Froglife runs a “Toads in the Road” scheme, where you can find out more information about helping toads on roads. They will not be able to help in all cases but the guidelines for the scheme are on the website, as well as all the information needed to apply for the toad crossing to be included in the scheme. 

Male common frogs may lie dormant at the bottom of the pond over winter and usually this is not a problem, so are the frogs dead or still in hibernation? 

If your pond is of a reasonable size and depth, ice should not cause a problem as native wildlife is adapted to the weather conditions. If there are shallow areas of water, then melting areas of ice will help the wildlife in the pond and provide water for birds and other wildlife. 

However, if ice has been present for prolonged periods it causes the toxic gases, which are naturally given off by decaying matter in the pond, to build up, causing ‘winterkill’ (death as a result of winter conditions). You can reduce the chances of this happening by gently melting a small area of the ice: place a saucepan of hot water on it, or you can leave a floating object, such as a ball, in the pond that can be removed once the ice has formed. 

If you would like more information about causes of death in frogs and toads, visit the Amphibian and Reptile Conservation website. 

This is an entirely natural part of the breeding process. The male frog will hold on to the female for a number of days so that he is available to fertilise the eggs. This embrace is called ‘amplexus’. Although the females do sometimes turn an unusual colour, this is nothing to worry about and she will return to normal when breeding is complete. 

Frogs and their spawn should not be moved from one pond to another as there is a risk of spreading infection and invasive pond plants. Frogs only require ponds for part of their life cycle, so it is possible that the new pond may not be a suitable habitat to support them. If you create the correct environment in your pond and garden, the amphibians will eventually find it and colonise naturally. 

If natural colonisation is not possible as there are no other frog populations nearby, or access for them is impossible because of busy roads, then one or two frogspawn clumps from a local garden may be introduced – but be extremely careful and don’t do this if there are any known infections or invasive water weed in the donor pond. 

Great crested newts are protected under the Wildlife and Countryside Act. If you have them in your garden pond, the main issue is when to carry out pond maintenance. The best time is during the autumn and winter months, outside of the newt breeding season. For guidance on managing your pond with great crested newts in mind, please see Natural England’s guidance notes.

There are three native newt species found in the UK – the great crested, the smooth or ‘common’ newt, and the palmate newt. Only the great crested and smooth newts are now widespread in Norfolk, with the palmate newt being confined to a very small number of sites. 

The great crested newt is the largest species at about 15 centimetres long. Their topside is very dark brown or black and the underside is orange or yellow with irregular black spots. The males have a distinctive and large serrated crest during the breeding season, and a wide tail with a silvery central line. Great-crested newts have full protection under the Wildlife and Countryside Act 1981. 

The smooth or common newt is about 8-10 centimetres long and has a pale grey-brown body with a bright yellow or orange underside with dark spots. A distinguishing feature is the presence of spots on the underside of their throat. During the breeding season males have a continuous wavy crest running along their backs and the underside of the tail. 

The palmate newt is very similar in size and colour to the smooth newt; however, the males do not have a very pronounced crest and have webbed hind feet. Females are more difficult to differentiate but the best way is to look at the throat, which in the palmate is usually a pale/translucent pink colour without spots. 

Visit the Froglife website for more information.

Yes. If a newt is relocated to a different pond, it will try to get back to its original pond the following year. However, any young it has in the new location will stay there.

The adder is the only venomous snake that can be found in Norfolk. It mainly inhabits areas of open heath and sand dunes but can be found in woodland. Adders are particularly active in spring and early summer. 

Adders are very shy and retiring creatures that will readily move away from any human presence well before potential contact. Adders will usually only bite if an attempt is made to pick them up, but their bite is rarely fatal. If you or somebody with you is bitten, it is very important that you stay calm and seek immediate medical attention. If possible, the affected body part should be immobilised. Symptoms may include dizziness, vomiting, and swelling. 

Adder bites can sometimes, though rarely, be fatal to pets. Take care when walking dogs through adder habitats, particularly in February, March, and April when the snakes have recently emerged from hibernation and may be slower to move out of harm’s way. 

If you encounter an adder, it is vital you never try to handle or provoke them in any way. Adders are protected under the Wildlife and Countryside Act 1981 and it is an offence to kill, harm, or injure them, or to sell or trade them in any way. 

Grass snakes mate during April after they come out of hibernation in March. The female will then lay her eggs in June or July in a warm place where the heat will allow the eggs to develop. This takes around ten weeks and the young will hatch from late August through September. If the weather has been particularly cold, then hatching may be delayed until October. 

Adder

Adders are found on heathland, dry commons, and in sunny woodland clearings. 

The basic ground colour ranges from ginger-brown to grey. Their distinguishing feature is the wide, dark, zigzag stripe running along the back that camouflages them against vegetation. This stripe is usually flanked by a row of spots running along each side. Occasionally, they can be plain brown or even black. 

The adder has a distinct "V" or "X" shaped marking on its head and the eye has a pupil with a vertical slit. 

Adders appear quite chunky, and males can reach a length of up to 60 centimetres, females up to 75 centimetres. 

Grass snake

Grass snakes are usually found in wetland habitats and grasslands. The basic ground colour is olive green and there is a distinct yellowish/off-white and black collar around the neck. There are dark side markings along the entire length of the snake. Its eyes have a round pupil. 

The grass snake has a smooth appearance and is the largest native UK reptile, with females reaching up to 150 centimetres in length, though males are generally smaller. 

Slow worms

Slow worms are very secretive creatures but can be found in a variety of habitats including gardens. They are not actually snakes, but the UK’s only legless lizard. 

The colour of slow worms varies from light or dark brown through to brick-red, but they are far less well marked than the adder or the grass snake.  

Males and females show marked differences when fully grown. Females very often have a thin dark stripe running along the length of the back and the flanks are speckled and stripped with dark brown or black. Adult males are more uniform in colour and occasionally have very distinct blue spots. Both sexes are around 40-50 centimetres long.