I first heard about this today in reference to something else (the Pink Iguana), but I think the story is really cool.
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The penguins pictured above are from Australia (the type Ed, Lynn and I saw) are threatened by other species (dingos, wild fox, etc.) on some islands. To protect the penguins, they have introduced a couple of Italian Sheepdogs (pictured below).
Apparently these dogs bond with the animals they are raised with and then protect the other animals. This is working very well with some Australian penguins.