Common Midwife toad, Alytes obstetricans
History and origin
The Common Midwife toad was first described by Laurenti in 1768, the scientific name of this species is Alytes obstetricans. Alytes in Greek means 'linked' or 'entwined' this is given because of the eggs that are linked together with that the males entwine around their hind legs. Obstetricans is Latin for 'midwife', the reason for this name is that the male inserts one of his toes into the females cloacae in order to help her lay the eggs.
They are characterised by their unusual reproduction style, they are the only French anura to mate on land, afterwards the males can be easily identified thanks to the eggs that he carries with him attached to his hind limbs.
- Eggs: The eggs measure about 2.5 to 5 mm in diameter.
- Tadpoles: The tadpoles measure 10 to 17 mm long when they exit the egg. In the case of autumn tadpoles which have been in a water hole that only averages under 20 C in summer, they hibernate and metamorphose in the following spring these tadpoles may grow up to about 50 mm long exceptionally up to 100 mm long.
- Juveniles: The juveniles measure 12 to 15 mm long when they exit the water.
- Adults: Adults measure up to 55 mm long, although averaging 40 mm long. =Morphology=
- Eggs: They are laid in separate balls linked by a rosary-like string. There are up to 80 eggs in a clutch.
- Tadpoles: Tail comes slightly onto the back. Nostrils are closer to the mouth then to the eyes. Their tail is over 1.5 times the length of the body.
- Adults: They are a small plump toad. they have a blunt snout, large head and vertical pupils. They have very small paratoïd glands. Their back is smooth for a toad yet still retaining some warts. The males do not have a vocal sac. =Patterns & colours=
- Eggs: They are yellowish, becoming darker with time but also more transparent, you can see the tadpole inside (eyes, tail).
- Tadpoles: They are light brown, their belly is bluish and their tail is light brown.
- Adults: Their back can be variable from dark gray to orange/yellow and sometimes light green with the warts being a darker shade of green. The very small paratoïd glands are sometimes orange. Their eyes are golden and the belly is white.
Found over much of western Europe. Present in most of France (excluding Alsace), eastern Belgium, northern Switzerland, possibly in far western Italy (?), found over Spain (excluding the south-west and southern central parts) found in the northern half of Portugal.
Subspecies - almogavarii - Found in north eastern Spain and a small area of France. - boscai - Found in north and western Spain and Portugal. - obstetricans - Found everywhere except for the Iberian peninsula and a small part of France.
- pertinax - Found in central Iberia.
The males are smaller then females. Males carry with them the eggs, this is a certain way of knowing a male, however males don't have any eggs all year round.
Males can be observed carrying eggs from march until august.
They feed on: 1/4 spiders ; 1/4 beetles ; and the rest is composed of flies, worms and other insects. Breeding specimens do not feed.
When they feel threatened, they tuck in their limbs and inflate their bodies up to appear larger, they may hold this inflated posture for about 5 seconds. They never emit a distresses call nor do they release a liquid when caught.
When the two meet, the female gets the male excited by giving him little knocks with her nose. When she is ready to mate, she'll let the male know by stamping her feet on the ground, the mating only lasts 10 to 20 minutes Max. the male grabs the female by the waist and the female should then push all of her eggs out as the male helps her by inserting one of his toes into her cloacae to pull out the eggs. The eggs then land between their legs, the male then showers these eggs with urine and sperm. After a pause, the male then puts his hind legs into the mass of eggs, so as they attach to the legs, then he uses his front legs to attach the eggs 'better' to him so as they don't fall off. Males carrying eggs may be observed from March until August. Females may mate and produce eggs up to 3 times a year. Males sometimes carry more then one females eggs. Carrying up to 170 eggs. Females prefer to mate with a male that isn't carrying any eggs, if males have eggs, the female only lay a limited number of her eggs. Males may go to the water to keep the eggs humid in mid-summer of during heat-waves. Observations show that in the opposite scenario, the males avoid putting the eggs into contact with the too-humid ground by raising their hind limbs. 3 to 6 weeks after being fertilised, the males look for a pond of other water source and release the eggs there a short time later the tadpoles leave the egg.
Sexual maturity, life span
The average life span for Alytes obstetricans is about 5 years, they reach their sexual maturity in their second year.
Adults are always terrestrial, they live within 100 meters of water, and their tadpoles, juveniles tend to grow up closer to the water. They hide sometimes in other animals hideouts, such as the Natterjack, or rodents. They are usually found hidden underground, in a ditch dug by themselves, using their front legs to dig and hind legs to push away the loose ground. The male doesn't sing before the month of march, the singing stops mid summer in the northern part of France, and sometimes continues until November-December time in the south. In the summer they spend most of their time in deep hideouts far away from the hot dry weather.
A whistle like sound heard often away from water. The call is a high pitch, poo...poo...poo one every 1 to 2 or 3 seconds. Specimens can vary the pitch of the call and when more then one specimen is singing it may seem as if they are responding to one another. A single specimen may be confused with an Owl, sound (p)www.oreilleverte.com:
Found from sea level to up to 2400 meters in the Pyrenees, in the Alps & Massif Centrale this species is rarely encountered above 1500 meters. The Midwife toad prefers a habitat with lots of sun light, light ground and water, however this species is absent from any floodable areas. This toad enjoys rather open places, such as fields, flat areas, old walls, lands, prairies... but is also encountered although less in forest like habitat, and maybe near abandoned buildings. In the north of it's range this species can be found in large colonies on south and south west facing hillsides. They inhabit also in their aquatic phase a large variety of different water conditions, from moving to still and even stagnant. Mostly with lots of fish, canals, lakes, mountain lakes... This toad is know for it's coexistence with man, they can be found in parks, gardens, buildings, ruins, cemeteries... The tadpoles can survive in water considered as 'bad' ecologically...
The eggs and tadpoles are in danger from water insects and the Viperine snake (Natrix maura). Adults are often hunted by birds and Viperine snakes (Natrix maura).