Natterjack Toad: Ecology and Conservation
The natterjack toad (Epidalea calamita) is Britain's rarest amphibian, restricted to fewer than 60 populations concentrated on coastal sand dunes, sandy heathland, and saltmarsh. Its loud, distinctive churring call carries up to a kilometre on warm spring nights — an extraordinary sound from such a small animal.
Ecology and Adaptations
Natterjacks are warmth-loving (thermophilous) toads adapted to open, sunny, sandy habitats. Unlike common toads, they run rather than hop — the distinctive yellow stripe down the back distinguishes them from common toads. They breed in shallow, warm, often temporary pools — characteristically sun-warmed sandy-bottomed pools that heat rapidly in spring.
The eggs and tadpoles of natterjacks are specialised for warm, shallow water that would be too hot for common toad development. This specialisation means that deep, shaded pools with cool water are largely unsuitable — the specific warm, shallow conditions natterjacks need are both rare and threatened.
Threats and Conservation
Habitat loss has driven natterjack decline — coastal development, agricultural conversion of dunes and heathland, succession of open sandy areas to dense vegetation (including rank grass, scrub, and trees reducing the open habitat they require), and loss of appropriate breeding pools have all contributed. Scrub encroachment is particularly insidious — it is visually benign but shade and root competition eliminate the bare, warm sandy areas natterjacks need.
Active conservation management includes scrub removal, maintenance of open sandy areas, creation and management of shallow breeding pools, and population reintroduction to historical sites following habitat restoration. NatureScot and Natural England coordinate national conservation programmes.
Legal Protection and Welfare
Natterjack toads are strictly protected under UK and European law — any survey or conservation work requires a licence. Their sensitivity to handling (stress, dehydration through permeable skin) means handling should be minimised to essential survey and conservation activities. Wet hands, brief handling, and prompt return to appropriate habitat minimise individual welfare impact from necessary handling.