Redefining 'Rare' - 6,000 Dolphins at a Time

Now, I'm just as much of a fan of the survival of obscure cetaceans as the next guy.

Perhaps I'm just quibbling with the National Geographic title, but how do you miss 6,000 Irrawaddy river dolphins?  And if there are more than 6,000 of them, were they/are they really rare?