Amphibians
Mallorcan Midwife Toad
Alytes muletensis · also called Mallorcan midwife toad, ferreret
The Mallorcan midwife toad was extinct, as far as anyone knew — a species known only from old bones in cave sediment, gone for thousands of years. Then in 1980 herpetologists searching a remote mountain gorge on Mallorca found it alive, a tiny relict population that had survived undetected in one of the most celebrated amphibian rediscoveries of modern times.
Overview
The Mallorcan midwife toad, Alytes muletensis, known locally as the ferreret, survives only in a handful of steep, narrow limestone gorges in the Tramuntana mountains of Mallorca. Like other midwife toads, the male carries the fertilised eggs wrapped around his hind legs for weeks until they are ready to hatch. Its tadpoles develop unusually slowly in cold gorge pools, sometimes taking close to two years to complete metamorphosis.
Extinct, then found alive
Known only from fossil bones and presumed lost after humans introduced predators to the island, the species was found living in 1980 in a gorge too steep and remote for those predators to fully reach — a natural refuge that had kept a tiny population going undetected.
A recovery in progress
Introduced snakes remain the central threat, but a sustained captive breeding programme has founded new, protected populations at additional gorges, moving the species’ trajectory from freefall toward a cautious recovery.
Status
Critically Endangered but increasing — one of Europe’s clearer amphibian conservation successes, though the species remains confined to a tiny natural range on a single island.
Mallorcan Midwife Toad: common questions
How was the Mallorcan midwife toad rediscovered after being thought extinct?
The species was first known to science only from subfossil bones found in cave sediments on Mallorca and was assumed to have died out long ago, likely after humans brought predators such as snakes to the island that the native amphibians had no evolutionary defence against. In 1980, a team of herpetologists searching remote, difficult-to-reach gorges in the island's Tramuntana mountains for an unrelated survey found tadpoles and adults of a small, living population that matched the fossil species, a discovery that stunned the scientific community and made the toad one of the best-known amphibian rediscoveries of the 20th century.
Why did the toad survive in only one place for so long?
The gorges where the surviving population was found are extremely steep, narrow, and difficult to access, which likely helped protect the toads from the introduced predators, particularly snakes, that are thought to have wiped out the species everywhere else on the island. These isolated microhabitats also offer the cool, humid, rocky conditions the species needs, effectively acting as a natural refuge that remained just inaccessible or unsuitable enough for the predators responsible for the toad's disappearance elsewhere to fully colonise.
What is being done to protect the Mallorcan midwife toad today?
Conservationists established a captive breeding programme not long after the species was rediscovered, and toads bred in captivity have been used to found new populations at additional protected gorges on Mallorca, spreading the species beyond its single original refuge and creating a buffer against the loss of any one site. Ongoing efforts include controlling introduced predators such as viperine snakes at key sites, monitoring for disease including chytrid fungus, and protecting the gorge habitats themselves from disturbance, and this sustained work has been credited with helping the population trend move from critical decline toward a gradual recovery.
Is the Mallorcan midwife toad like other midwife toads?
Yes, in its basic reproductive behaviour it shares the defining trait of the genus Alytes, in that the male carries the fertilised egg strings wrapped around his hind legs for several weeks, keeping them moist and protected until they are ready to hatch, rather than the female or neither parent providing this care as in most frogs. It differs from the more widespread common midwife toad of mainland Europe mainly in its extremely restricted range, its adaptation to cold mountain gorge pools, its notably slow tadpole development, and its status as a separate, distinct species confined entirely to Mallorca.