The Natterjack Toad (Epidalea calamita) is a distinctive species of toad found across parts of Europe. Known for its loud, rasping mating call and characteristic yellow stripe running down its back, the Natterjack Toad is highly specialized for living in sandy and coastal habitats. Here’s a detailed look at this fascinating amphibian:

Key Features of Natterjack Toad

1. Physical Appearance:

Size: Natterjack toads are relatively small compared to other toads, with adults measuring between 2 to 3 inches (5 to 7.5 cm) in length.
Coloration: Their skin is typically brown, olive-green, or gray, mottled with darker spots. A prominent feature is the bright yellow or pale green stripe that runs down the center of their back.
Skin Texture: Like many toads, their skin is rough and warty, offering some protection from predators and the elements.
Eyes: They have golden to greenish eyes with horizontal pupils, a typical trait of toads.
Limbs: Natterjacks have relatively short legs, but they are stronger and more adapted for running than jumping, unlike most other toads.

2. Habitat:

Sandy and Coastal Areas: Natterjack toads prefer sandy heaths, dunes, and coastal grasslands, where the loose soil makes it easier for them to dig burrows.
Temporary Ponds and Pools: They are often found in areas with shallow, temporary water bodies, which are crucial for their breeding. They tend to avoid permanent, deeper bodies of water.
Wide Range in Europe: Their distribution spans several European countries, including the UK, Ireland, France, Spain, and Scandinavia, but they are becoming rare in many regions.

3. Life Cycle:

Breeding: Breeding occurs in late spring and early summer, usually after heavy rainfall, when males gather around shallow pools or flooded areas and call to attract females.
Mating Call: The Natterjack is famous for its loud, rasping, and persistent mating call. This call can be heard from long distances, and males can call continuously for hours. They have a unique vocal sac that amplifies the sound.
Eggs: Females lay long strings of eggs in shallow water, usually attached to submerged plants. Each female can lay several thousand eggs at a time.
Tadpoles: Tadpoles hatch within a week and develop rapidly in the shallow, often temporary pools. Unlike other amphibians, Natterjack tadpoles grow quickly to adapt to the ephemeral nature of their breeding sites.
Metamorphosis: After about 6 to 8 weeks, the tadpoles metamorphose into juvenile toads (called toadlets) and leave the water to live on land.
Terrestrial Life: Once on land, Natterjack toadlets begin their terrestrial life, foraging and growing over the next 2 to 4 years until they reach sexual maturity.

4. Behavior:

Nocturnal: Natterjack toads are primarily nocturnal, emerging at night to feed and breed. During the day, they hide in burrows or under cover to avoid desiccation and predators.
Running Rather than Hopping: Unlike most toads, which hop, Natterjacks are known for their running gait. Their relatively short legs are adapted for running rather than jumping.
Burrowing: They are skilled burrowers and dig shallow burrows to escape the heat and dryness of the day. In sandy habitats, they can burrow quickly using their strong hind limbs.
Breeding Migration: During the breeding season, they migrate to specific breeding ponds, often traveling several kilometers to find suitable water bodies.

5. Diet:

Carnivorous: Natterjack toads are insectivores and feed on a variety of invertebrates. Their diet includes:
- Beetles
- Ants
- Spiders
- Worms
- Caterpillars
Foraging Behavior: They hunt by ambushing their prey or actively searching for food during the night. Their sticky tongue helps them capture prey quickly.

6. Defense Mechanisms:

Toxic Skin: Like many toads, the Natterjack secretes a mild toxin from glands in its skin, particularly the parotoid glands behind its eyes. This toxin helps deter predators, though it is not harmful to humans.
Camouflage: Their mottled brown and green skin helps them blend into their sandy, grassy environments, offering some protection from birds and other predators.

7. Lifespan:

Natterjack toads can live up to 12 to 15 years in the wild, although many individuals do not survive past their juvenile stages due to predation and environmental challenges.

8. Conservation Status:

IUCN Red List: The Natterjack toad is classified as Least Concern globally, but populations are declining in many parts of their range.
UK Status: In the UK, they are considered endangered, with significant declines due to habitat loss, agricultural development, and changes in land management practices.
Habitat Loss: The destruction of sandy heaths, coastal dunes, and temporary ponds due to urbanization, intensive farming, and changes in land use has been a major factor in their decline.
Conservation Efforts: Conservation programs aimed at protecting and restoring suitable habitats are in place. In the UK, efforts include creating and maintaining breeding ponds, managing coastal habitats, and captive breeding programs to reintroduce toads to their native areas.

9. Adaptations:

Adapted for Dry Environments: Natterjacks are well-suited to dry, sandy environments. Their burrowing behavior helps them avoid extreme temperatures and dehydration.
Rapid Development: Their tadpoles develop rapidly to cope with the ephemeral nature of the shallow pools they breed in, many of which dry up quickly.
Loud Mating Call: Males have developed a loud, distinctive mating call that can carry over long distances. This is crucial in sparse environments where breeding ponds are far apart and females need to locate males easily.

10. Interesting Facts:

Name Origin: The name “Natterjack” is thought to come from the Old English word “natter,” meaning “rasping” or “buzzing,” referring to the toad’s distinctive call, and “jack,” a common colloquial term for small animals.
Running Toad: Unlike other toads that prefer to hop, Natterjacks are more likely to run in short bursts, a unique feature among amphibians.
Longevity: Despite their small size and delicate appearance, Natterjack toads can live for over a decade, making them one of the longest-lived amphibians in their range.
Breeding Sites: Natterjack toads are highly site-loyal, meaning that once they find a suitable breeding pond, they often return to the same location year after year.
Cold-Adapted: Natterjacks are well-adapted to cooler climates and can survive in northern latitudes, including parts of Scandinavia, making them one of the northernmost amphibians in Europe.

11. Threats:

Habitat Loss: The destruction of coastal and heathland habitats for agriculture, urban development, and tourism has severely impacted their populations.
Climate Change: Changes in precipitation patterns due to climate change affect the availability of temporary breeding ponds, which are crucial for their reproduction.
Predation: Eggs and tadpoles are vulnerable to predation by birds, fish, and invertebrates, while adult toads face threats from larger animals like snakes and mammals.
Pollution: Agricultural runoff and pollutants entering temporary water bodies can harm Natterjack tadpoles and reduce breeding success.

The Natterjack Toad is a highly specialized amphibian, uniquely adapted to its environment, with a fascinating biology and behavior. Conservation efforts are vital to ensuring the survival of this distinctive species, which plays an important role in the ecosystems of Europe’s sandy and coastal landscapes.