Common midwife toad (Pyrenees' Biodiversity)

Common midwife toad

Alytes obstetricans

Summary ⁷

The common midwife toad, Alytes obstetricans, is a species of midwife frog in the family Discoglossidae. It is found in Belgium, France, Germany, Luxembourg, the Netherlands, Portugal, Spain, Switzerland, and the United Kingdom (although, in the latter, only as an introduction). Like other members of its genus (Alytes), the male toad carries the eggs around entwined on his back and thighs until they are ready to hatch.

Life history, abundance, activity, and special behaviors ⁸

These frogs are well known for their male parental care behavior. The males attach the egg masses to their body and carry them until the eggs hatch, at this point the males release the tadpoles into bodies of water. The females can produce up to four clutches of eggs per breeding season. Mating season varies throughout the range. In Westfalen, Germany one can find males carrying eggs between the end of March, and the beginning of August. Around the city of La Coruña, males with clutches of eggs were observed from mid-February until August. In mountain populations most males carry eggs well into August. Although males call mainly by night, they are known to call from their hiding places during the daytime. The call is a high-pitched, explosive, musical "poo...poo…poo…", about one call every 1-3 sec, usually higher and shorter than Bombina. The female seeks out the male and presents herself to him. The male grabs the female in the lumbar region. The male stimulates the females cloacal region by scratching it with its toes. After about 35 minutes, the male suddenly constricts the female's flanks. She extends her hind legs and ejects an egg mass. The male then releases his lumbar grip, takes an axillar hold and inseminates the eggs with a quantity of liquid sperm mass. After 10-15 minutes, the male distends the egg mass with his hind legs , plies them alternatingly to his body and extends them again until the strings of eggs are wound around his ankles. A male can copulate anew and carry up to three clutches around his legs with a total of 150 eggs or more (Schleich 1996). Males keep the egg mass moist by microhabitat choice, or by taking short baths. Larvae hatch after 3 to 6 weeks. The males seek out small water bodies to discard the egg strings with the hatching larvae. Upon hatching, the larvae are about 15 mm and metamorphose the next year, when they have reached a maximum length of 5 to 8 cm (Engelmann 1985).