Mallorcan Midwife Toad
Alytes muletensis
Mallorcan Midwife Toad
Alytes muletensis
CC goal
53 breeders
As at 05/2024
CC goal
425 animals
As at 05/2024
CC goal
53 breeders
As at 11/2023
CC goal
425 animals
As at 11/2023
In the beginning, there were a few bones. At the end of 1974, two scientists at the Archaeological Museum of Deyá on the Mallorca stumbled upon some 14,000-year-old amphibian remains that had been found in a karst crevice in the Muleta Cave on the Balearic island. It quickly became clear that they were dealing with an unknown Pleistocene species. In 1979 they described it as “Balearic Toad” (Baleaphryne) and gave it the species name muletensis after the cave where it was found. It was assumed that it had become extinct after the appearance of man on Mallorca in ancient times.
Primal Relatives
Egg-bearing male of the common midwife toad (Alytes obstetricans) from Wuppertal, Germany
Ready to swim away! The tadpoles of the common midwife toad are still compressed into small balls in their eggs, but on contact with water they will burst the egg shells and swim away.
The Bosca midwife toad (Alytes obstetricans boscai) is only found in the western part of the Iberian Peninsula.
The Almogavar midwife toad (Alytes almogavarii), which has only recently been recognised as a distinct species, lives in the eastern Pyrenees.
The Iberian midwife toad (Alytes cisternasii) is common in the central areas of the Iberian Peninsula.
The Southeast Iberian midwife toad (Alytes dickhilleni) is also critically endangered. It is found only in the mountains of Andalusia.
The Mallorca midwife toad (Alytes muletensis) is the most endangered species of the genus. It is only found in the north of the popular vacation island of Mallorca.
The mammoth among toads
The reports of the Pleistocene find reminded biologist Joan Mayol that he had found a common midwife toad on Mallorca in 1978. He fished the little animal from his collection jar and was astonished to discover that on closer inspection it was anything but ordinary: he had discovered a living fossil! On Mallorca, he succeeded in finding living tadpoles and freshly metamorphosed young toads in the remote gorges of the Serra de Tramuntana. A scientific sensation! For the frog researcher, this was comparable to an encounter with a mammoth in the flesh.
Hidden in deep canyons
However, even after an extensive search, only a handful of sites were found. Apparently, the toads had only narrowly escaped extinction. Once they were widespread on Mallorca. Presumably they were simply eaten up by the viper snake and the Iberian water frog, which had already come to the island with man in ancient times. In the ravines of the Serra de Tramuntana, however, it was too cold for the invaders, so that the toads found a last refuge here.
Heavily emancipated: Males as midwives and childcarers
In the case of the Mallorcan midwife toad, the male wraps the spawning cords around his hind legs and sometimes even pulls them right out of the female – hence the name.
The male now carries the eggs around with him at all times, providing an optimal climate for development.
After about three to four weeks, the larvae are about ready to hatch, easily recognizable by the now dark color of the eggs.
The male now goes into the water, where the tadpoles hatch.
The tadpoles are now swimming around on their own, while the male has freed himself from the spawning cords, which can still be seen in the water here
Depending on temperature, the development of the tadpoles can take an unusually long time – up to one and a half years are possible!
During this long development period, the tadpoles grow to an astonishing 8 cm in length. This ranks them among the largest tadpoles in Europe.
Before they go ashore, however, they shrink back to size. The adult toads are no longer than 4 cm.
The invisible enemy
It was uncertain how long the small remaining population would survive in the future. Therefore, in 1985, some animals were brought to the zoo on the Channel Island of Jersey by the conservationists of the Durrell Wildlife Conservation Trust. It was possible to breed and distribute the small toads, so that a release into the wild on Mallorca could begin as early as 1989. Thousands of tadpoles and young toads were released under scientific management, but only in ravines where the species had disappeared. This precautionary measure proved to be absolutely right. In the meantime, a previously unknown enemy had spread in Europe: the chytrid fungus Bd. It can cause mass mortality among frogs. By the time it was scientifically described in 1999, it was already too late: the fungus had come to Mallorca with the abandoned toads.
A quarter of the Mallorcan midwife toads living in the wild are offspring of the zoo's progeny.
© Serge Bogaerts
Things remain dicey
Nevertheless, the reintroduction program was a success: of 25 sites where the toads are found today, almost half can be traced back to it. A quarter of the Majorcan midwife toads living in the wild today are descendants of the zoo’s offspring. But the fungus remains just as much a threat as the old enemies water frog and viper snake. And they now have a powerful ally: climate change. Rising temperatures could help the plague break out or allow the invaders to push even further into the cool canyons. In addition, there are problems with agriculture and pollution. So, there is still a long way to go before the all-clear is given. It even is quite conceivable that the habitats will become uninhabitable for the toads in the medium term. This does not have to mean their final end in nature, because one day the invaders and the fungus may be eradicated and the biotopes renaturalized. However, this would only benefit these living fossils if they survive until then in human care, in zoos and with private keepers.
Conservationists from Durrell Wildlife Conservation Trust/Jersey Zoo at work in theSerra de Tramuntana auf Mallorca © Dawn Fleming/Durrell Wildlife Conservation Trust
For breeders
Basic information on biology and breeding
The Majorcan midwife toads is very suitable for keeping in a terrarium and can also be recommended to beginners and school vivariums without hesitation. Terrariums of 80 x 30 x 40 cm are suitable for keeping a group of up to 12 animals. Gravel substrate, hiding places made of stone slabs, shards of clay or pieces of cork bark. Dry and moist hiding places are important. A large water bowl with a safe exit is used for bathing and spawning. They should be kept at room temperature. Feed with all common food animals up to the size of medium-sized crickets. The tadpoles can be raised in large groups in normal aquaria without any problems.