Biologists have discovered the first truly monogamous amphibian, the Peruvian poison frog in the rainforest of South America. They've also discovered a fascinating reason that these frogs remain committed to each other: it all boils down to real estate!
After mating, a female mimic poison frog lays her eggs on the surface of leaves. The male frog then takes away the tadpoles that hatch, carrying them one by one on his back to pools of water which collect in bromeliad leaves high up in the branches of trees.
Each of half a dozen babies are put into their own tiny pool, which he then looks after. When the tadpoles become hungry, the male calls to his female partner who arrives to lay a non-fertile egg in each pool, which the tadpole eats as food. [...]
Their tadpoles cannot survive without the care of both their father and mother, as there is too little natural food in their smaller pools. So the adult frogs stick together.