History and origin
The Natterjack toad was first described by Laurenti in 1768, the scientific name of this species is Bufo calamita, formally Bufo calamita. Bufo meaning toad. Bufo is of unknown origin, Calamita is Latin for 'reed' from their habitat.
Characteristics
This species is characterised by a light thin line running down the back, also they have very short limbs.
Description =Size=
- Eggs: The eggs are about 1 to 1.7 mm in diameter, they are laid in a cord that is up to 2 m long and is about 6 mm thick.
- Tadpoles: The tadpoles measure 8 mm long when they hatch, growing up to 36 mm long.
- Juveniles: The juveniles measure 6 mm long at least when they exit the water.
- Adults: Adults measure up to 100 mm long max. (males ave.: 70 mm; females ave.: 80 mm).
=Morphology=
- Eggs: The eggs are laid in long cordons. There are up to 4000 eggs in the cord and they are arranged in one or two per row.
- Tadpoles: Their tail doesn't come up onto the back. Their eyes are close to one another.
- Adults: A robust toad, they have short limbs. They have very prominent paratoid glands which are parallel. They have very warty skin, and horizontal pupils. They have slightly webbed feet, no dorsolateral folds. They have an external vocal sac situated under the throat.
=Patterns & colours=
- Eggs: They are black embryos incased inside a transparent cordon.
- Tadpole: They are black, they obtain their yellow dorsal stripe just before metamorphosing.
- Adult: They have a light line running down the middle of their back, this line is usually yellow. Their background pattern reminds you of an army camouflage with a general dark colour (ex: dark green) with blotches and irregular areas of the same colour of a lighter shade (ex: light green). Their general dorsal colour is usually dark green, olive, brown or sometimes light green usually with lighter colours which are situated on the warts, these colours are usually yellow, light green or sometimes reddish. Their eyes are greenish golden. Their belly is usually whitish with small spots of green.
Geographical range They are found throughout the Iberian peninsula, across France, Germany, Benelux, Northern Switzerland, Chez Republic, Poland, the Baltic states, Denmark, extreme south western Sweden and isolated populations in the UK and in Ireland. Also found in western Belarus and extreme north western Ukraine.
Subspecies
None described.
Sexual differences
Males have stronger front legs. Males have dark nuptial pads on the first three fingers. Males have a more blue coloured throat due to their vocal sac, females throats are whitish.
Seasonal variations
Males nuptial pads are visible during the breeding season.
Diet
1/3 of their diet is composed of flies, 1/5 of ants, other prey are made up of spiders and other insects. Tadpoles feed on vegetation but may become cannibalistic.
Defensive habits
When they feel threatened they inflate their bodies and secrete a liquid from their skin and paratoid glands. If approached, they may turn and run away like a mouse.
Reproduction
The breeding season can last up to 1 to 2 months (starts in March) and reoccurs in October (in the Mediterranean area). The specimens from the Mediterranean area do not reproduce every year. Reproduction sites are usually small areas of shallow water, this water may or may not be permanent. This species can hold on until the flood season to lay their eggs in new small areas of water. This area of water must be as low as possible in fish and insects. Once the two sexes meet the male doesn't take long before mounting the female. But if the females reach the water without a male then they will become impatient and sing a love song to complain and attract a male. When time has come to lay the eggs the male will caress the females flanks helping her to lay, once the cord of eggs has started to emerge from the female, the male will take it and pull it to the nearest plant and then the female can lay and pull out the eggs alone, they stay together for a few hours before the male finally disappears.
Sexual maturity, life span
The average life span for Bufo calamita is about 7 years for males and 15 years for females, they reach their sexual maturity in their second year in the south and sometimes as late as their fifth year in the north.
Habits
Active at night preferring cool nights with no wind, although can be rarely encountered in day time. If disturbed this toad usually runs in short bursts like a small mammal rather then hope or walk, this can be done as fast as a mouse. They can climb very well, even on very steep places. They often hide in small burrows sometimes with other Natterjack, they dig these burrows in loose soil. Otherwise this toad hides in other burrows of other animals (mice...) or under logs, stones... during the day. The newly metamorphosed toads are active by day but become night active over a period of time.
Call
Males sing when sat in the shallow water. They call a rolling croak 'errr...errr...errr...', each croak lasts for about 1 to 2 seconds and can be heard from up to 2 km away on a quiet night, sound (p)www.oreilleverte.com:
Habitat
Found living at under 1700 meters in altitude. They live in typically open areas with soft ground, scattered low vegetated areas and hiding places made up of wood, stones... These habitats must be exposed to a lot of sunlight. Their aquatic habitats are characterised by a very sun-lit area, shallow water and little or no fish and other predators such as water insects. (temporary water holes).
Predators
They are hunted by birds, Natrix snake species (Grass snake and Viperine snake). Dragonfly larva and other water insects eat the tadpoles.
They are found throughout the Iberian peninsula, across France, Germany, Benelux, Northern Switzerland, Chez Republic, Poland, the Baltic states, Denmark, extreme south western Sweden and isolated populations in the UK and in Ireland. Also found in western Belarus and extreme north western Ukraine. 
Male Natterjack toad, Bufo calamita calling - © Daniel Phillips
