There was a recently published story on how the Gentoo Penguin, currently considered to be a single species with various colonies on Antarctica and the near-Antarctic island groups, might actually be four species as there seems to be no interbreeding between colonies and there are size differences and genetic differences between colonies. That sounds reasonable: not way out of line.
Gentoo Penguins: one species or four? — SANTA MONICA BAY AUDUBON SOCIETY BLOG

