The Natterjack Toad is our second rarest amphibian, after the Pool frog. © Tony Phelps

The Natterjack toad has short legs and a warty skin with a yellow dorsal stripe. The head has large parallel parotoid glands. The Natterjack is also known as the ‘running toad’ as the short hind limbs enable it to run after prey.

The main preferred habitats are sandy heathland, sand dunes and saltmarshes where they breed in shallow temporary ponds.

This endangered species is one of the rarest amphibians in Britain, has declined markedly in numbers and range during the last century and receives full protection in law.

The main colonies of Natterjack toads are found along the Sefton Coast between Lancashire and Dumfries, with a few in Norfolk and Lincolnshire and only reintroduced colonies in Surrey and Hampshire.

The Natterjack produces deterrent toxins from the parotoid and other glands although one predator, the grass snake, appears to be unaffected.

The Natterjack has multi-colour warts and a distinctive yellow stripe. © Steve Langham

The size of the male Natterjack toads normally ranges from 6-8cm but can occasionally reach 10cm from snout to vent. They are robust animals with flattened bodies and short limbs which end in only part-webbed feet. Natterjacks have green/gold-coloured eyes with horizontal black pupils but lack visible ear-drums [unlike the common frog]. The paired parallel parotoid glands, which secrete toxins, are located behind the eyes.

The toad’s dorsal surfaces are generally light brown, olive or grey with a profusion of warts which may range in colour from red, dark brown or green. It usually has a yellow stripe that extends from the top of the snout down the back. The ventral surface is creamy-white with a scattering of dark green spots although the throat lacks spots and is tinged blue or purple in the male. Male Natterjacks possess large external vocal sacs located underneath the chin and nuptial pads on the insides of the three inner digits. These pads regress after the breeding season. It is described as being Europe’s noisiest amphibian as its chorus can be heard over several kilometres.

There may be regional variation in colour and size. Natterjacks from the Iberian Peninsular are often large and may lack a clear dorsal stripe. In some individuals the green patches on the back may be more extensive and so be more similar to the Green Toad [Pseudepidalea viridis]. Natterjacks have the capability of lightening or darkening their skin according to the background habitat and so gain benefit from increased camouflage. At low temperatures this toad may appear near-black in colour.

Natterjack females are usually larger than the males but do not possess vocal sacs or nuptial pads.

The Common toad [Bufo bufo] can be distinguished from the Natterjack [Epidalea calamita] as it has less prominent warts and an oblique parotoid gland.

A pair of Natterjacks hunkered into sand.

A Natterjack toad in profile.

The Natterjack occurs in South-west and Western Europe, east to Belarus and the Ukraine but is absent in South-East Europe. In the UK the Natterjack is at the northerly edge of its range and relatively few populations remain.

This species naturally occurs in only 39 sites in the UK but has been introduced to a further 13 locations some of which had a previously recorded occupation by the Natterjack toad.

Natural populations in Surrey declined drastically and one or two reintroductions have taken place.

National distribution for the Natterjack Toad

In Britain, which is in the north of its range, the Natterjack prefers open, unshaded habitats with loose, sandy soil suitable for burrowing. It is typically found in lowland heaths, sand dunes and slightly brackish waters and prefers to breed in shallow temporary ponds.

On the Continent it occurs in a wider range of habitats with an elevation up to 2400m.

The sand dunes of the Sefton coast are ideal habitat for Natterjack toads. © Sarah Drover

Although the adult Natterjack toads are nocturnal in their behaviour the young toadlets are clearly diurnal after metamorphosis. However, in their second year this preference is less dominant.

Survey in late March-September. Adults mainly nocturnal but juveniles often diurnal. Natterjacks can become active after night temperatures reach over 8°C and daytime up to 15°C. Normally the adults shelter in holes and burrows during the day but Toadlets can be found scattered over a wide territory amongst the short vegetation.

Natterjack toads are prolonged breeders and, depending on the weather, the breeding period can extend from late March to the beginning of August but is usually late April to June in Britain.

Natterjacks feed on a wide variety of small prey invertebrates and these include ants, worms, woodlice, spiders, molluscs, ground beetles, moths and other insects. Initially the tadpoles feed on the algae found on leaves and stems of aquatic plants but later can be seen as a shoal as they aggregate to scavenge dead animals such as fish and tadpoles.

Adult Natterjacks are ferocious predators and are capable of running after any moving prey item. Their short hind legs are perfectly adapted for this purpose. On sighting movement it sits with its head towards the prey, opens its mouth and with an extraordinarily fast tongue flick captures the tasty item on the sticky end of the tongue.

Freshwater shrimp

Slug

Spider

The main predators include crows, magpies and herons but predation can also take place by rats, stoats, weasels and Grass snakes.

During the day many predators are active and one way in which this toad avoids attention is by sitting in the entrance to their burrows – in this way they can sun themselves in relative safety. The approach of larger animals will cause the Natterjack to retreat into its burrow. Toadlets can gather in close proximity beneath low-lying vegetation.

The reaction to approaching Grass snakes is quite dramatic. As the toad is threatened it inflates its body and stretches its legs out so as to look as tall and large as possible. This may well avert the attack if the Grass snake is conned that its potential prey is too large to swallow.

Great crested newts will voraciously predate Natterjack tadpoles. This has caused an ecological embarassment in some areas, where the protected Great crested newt has colonised natterjack pools where it predates equally protected Natterjack tadpoles.

Rook (Crow family)

Great crested newt

Grass snake

Natterjacks will shelter communially, in individual hollows beneath refugia.

Natterjacks dig burrows in which they tend to hibernate up to 60cm beneath the ground. They also are known to use small mammal burrows or even those of Sand Martins.

Day burrows are more shallow, and are situated closer to feeding grounds or spawning pools. The toads will readily burrow beneath refugia or beached flotsom. It is common for many toads burrow below the same refuge, in a series of adjacent shallow hollows.

Driftwood on a semi-vegetated beach offers ideal shelter for Natterjack toads.

A Natterjack burrow leading to a shelter beneath beach refugia.

A tiny Natterjack toadlet, that has just emerged from its pond. © Steve Langham

Male Natterjacks arrive at the shallow breeding pond before the females. They have a remarkably noisy rasping call which commences after sunset and continues for several hours - choruses can be heard for over a kilometre. The nuptial pads developed by the male in preparation for breeding aid in grasping the female during amplexus. Although most males await the females in the shallow margins of the pond a few may wait on the pond side ready to intercept a passing female. If an over-amorous male grabs another male a squeaky release croak is given.

During amplexus the female lays a single string of spawn in the bare shallows of the pond and this is fertilised by the amplectic male. After releasing the spawn the female leaves the pond. The spawn string can contain 3,000-4,000 eggs, initially laid as a double row but this later settles into a single row. [The eggs in the spawn string of the Common toad remain as a double row].

The Natterjack eggs are well-adapted to surviving the rapidly drying-out conditions found in the shallow breeding ponds. They hatch into tadpoles within 7-10 days and can achieve metamorphosis into Toadlets in 6-8 weeks.

3000-4000 eggs in spawn string. Tadpoles can be heavily predated by beetle and dragonfly larvae if in a permanent waterbody – hence Natterjacks can be more successful in ephemeral ponds – despite the risks associated with rapid drying out.

Toadlets are very small and dark on emergence but do possess a definitive yellow dorsal stripe typical of the adult toad.

Natterjack spawn separates into single strings. © John Newton

A small one-week old Natterjack tadpole.

Endangered. Protected under the 1981 Wildlife and Countryside Act. About 50+ breeding sites nationally. Natural England Species Recovery Programme

• Natterjack toad UK BAP - species action plan
• SARG Natterjack toad photo gallery