Walking through a forest on Bawean Island, Indonesia, after a long and frustrating day in the field, Mark Rademaker came face to face one of the world's rarest wild animals, a kind of warty pig. 

"Out of the blue there was a fully grown male in front of me, with these big warts and long, white sideburns fanning out from his head," says Rademaker, of the VHL University of Applied Sciences in the Netherlands.

"We looked at each other for what felt like an eternity—perhaps it was only a split second—and he just took off into the bushes. I still like to think about that moment." (See "Exclusive Video: World’s Biggest Pig Revealed.")

What we know about the Bamean warty pig is equally elusive, simply because most scientists aren't interested in studying the genus of animals more popularly known as bacon. Almost all of the world's 17 wild pig species are threatened with extinction, though few have been studied.

Enter Rademaker,