Natterjack Toad

Bufo calamita


Habitat
Found in areas with short vegetation, sandy heaths, and upper salt marsh pools that have some sort of freshwater input.

Geographical spread
W and Central Europe, eastwards to W Russia, NW Britain and in Merseyside, Cumbria, Lincolnshire, Norfolk and Northamptonshire in England S Scotland SW Ireland.

Current population
15,000-20,000 breeding adults.

Status
Is protected under the Wildlife and Countryside Act 1981 in Britain. Habitat is also protected under European legislation.

Size
Up to 10cm but normally 7-8cm; females larger than males.

Weight
More than 20g and more if individual is spawning.

Average life expectancy
On average males live for 3 years and females for 4 years but males can live up to 9 years and females up to 15 years.

Normal diet
Will eat almost anything it can overpower such as crickets, slugs and worms.

Normal lifestyle
Emerges from hibernation in late March. The Natterjack toad is nocturnal and burrows into the sand (using its forelegs) during the day. Breeding takes places from late April to June, but females may not breed every year. Only the males croak, usually in chorus, beginning at dusk. On quiet evenings a chorus can be heard up to 2km away. The croaking is carried out in the water, the male expands is vocal sacs, forcing air into the lungs across the vocal chords, the inflated sac acting as a resonator. After mating, spawning occurs in shallow water and the spawn is produced in a double band up to 5-6ft long which splits in to a single band as it absorbs water. Each string of spawn contains about 3,000 eggs. Tadpoles develop more quickly than other frog and toad species, leaving the water after 6-8 weeks. Adults hibernate during the winter months (October to February).

Previous geographical spread
In Britain has disappeared from its former haunts in Surrey, Hampshire, East Anglia and Dorset. Extinct in Wales due to holiday resort development on dunes.

Reasons for decline
Habitat destruction, requires specialist habitat of mobile dunes or sand which is often being encroached upon for development, forestry and agriculture. Acid rain has also decreased the number of suitable breeding sites.

Conservation projects
Between 1992 and 1995 English Nature carried out a Species Recovery Scheme in which new populations were established at former sites in Dorset, Lincolnshire, Suffolk and Surrey. Results from this have been fairly successful. Since then this scheme has been taken over by the Herpetological Conservation Trust (HCT). Natterjacks are being reestablished within their former range and work is focusing on Surrey and Northampshire. Although these animals are fairly difficult to rear in captivity, captive-bred spawn are being used to reestablish this species.


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File last modified Thursday, October 3, 1996