June 26, 2009—Caught during a steamy moment in a lava tunnel in 2006, these two apparently mating bats—members of a new species—are each no bigger than a human thumb, scientists reported June 24.
Weighing just 0.2 ounce (5 grams), Aellen's long-fingered bat was discovered on a volcanic island in Africa's Comoros chain. DNA analysis later confirmed the bat as a unique species.
Subsequent genetic tests revealed that the bat is also found on the west coast of the island of Madagascar, said study team member Manuel Ruedi, a curator at the Natural History Museum in Geneva, Switzerland.
Since neighboring Madagascar is much older than the Comoros (regional map), the team suspects that the moth-size mammal lived on Madagascar before migrating to the Indian Ocean archipelago in the distant past. (Related: "Hurricanes Blow Away Bats, Spread Genes to New Islands.")
Bat diversity in both the Comoros and Madagascar has been poorly studied, Ruedi said. But the latest genetic-testing technology makes it easy to distinguish between bat species that can look very similar, he added.
As for the amorous image above, Ruedi said mating bats are a rare catch, "especially when it involves an unknown species!"