The male midwife toad carries his offspring on his back until they hatch.

Nature · Published 3 October 2026 Swipe more like this →

In short: In the world of amphibians, the common midwife toad defies convention. While most species abandon their eggs in water, the male Alytes obstetricans takes on the role of primary caregiver. He wraps strings of eggs around his legs, protecting them for weeks until they are ready to enter the water.

The common midwife toad, a small terrestrial amphibian reaching about 5 cm in length, is part of the genus Alytes. Unlike many amphibians that are obligate breeders in standing water, this species has evolved a unique reproductive strategy. After mating, the male gathers the egg mass, teasing it out to wrap the jelly-like strings securely around his back and thighs. He carries these eggs, which can number up to 150 across three clutches, until they are ready to hatch.

During this incubation period, which lasts between 3 and 8 weeks, the male ensures the eggs remain moist by seeking out damp environments or taking occasional swims. He may even secrete protective substances through his skin to shield the developing embryos from infection. Once the larvae are prepared to emerge, the male travels to a calm body of water—such as a pond, ditch, or even a garden flowerpot saucer—to release them. These larvae then undergo metamorphosis, developing limbs and losing their tails to become juvenile toads.

Beyond its biology, the midwife toad holds a place in the history of science. In 1971, Arthur Koestler published The Case of the Midwife Toad, which examined the controversial work of Paul Kammerer. Kammerer had claimed to demonstrate Lamarckian inheritance through experiments with these toads, a narrative that became a significant case study in the sociology of science and the evolution of scientific paradigms. Today, the species is found across parts of Europe, including France, Germany, and Switzerland, though it faces threats from habitat loss.

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