SEPARATE species can arise even when animals share the same habitat. The latest evidence comes from the singing habits of several species of indigo bird, a type of African finch.
Like cuckoos, indigo birds are parasitic, with each species laying its eggs in the nest of a particular species of firefinch. Now a study led by Michael Sorenson of Boston University in Massachusetts suggests that the different indigo bird species evolved when their ancestors switched hosts ().
Indigo bird hatchlings learn the song of the firefinch species that raises them, and as adults they seek…
