Bats living side-by-side may, in effect, be in different worlds. Two studies of the animals' beeps find that their hearing is differently tuned in ways likely to affect their mating and hunting.
On two Indonesian islands, three groups of the large-eared horseshoe bat hunt in the same forests but rely on different sound frequencies to detect insect prey, says Tigga Kingston of Boston University. The three groups of Rhinolophus philippinensis appear to be splitting into new species, she and Stephen Rossiter of Queen Mary College in London report in the June 10 Nature. If so, this would be the first mammalian example of a species dividing within a habitat, Kingston says.