From:
The Search for the Ivory-Billed Woodpecker
http://www.nature.org/ivorybill/search/

Reward Offered For Evidence of Ivory Bill
But four years and many search parties later, no additional proof of the bird's existence has emerged.

Now an interested citizen has offered up a $50,000 reward to anyone who can point researchers to the ivory bill. The reward will go to a non-paid searcher who provides video, photographs or other compelling evidence that leads scientists to a live ivory bill.

"We have to produce some undisputed evidence of the bird — a feather or a clear photograph — to convince the scientific community that the ivory bill is out there," said Allan Mueller, avian conservation project manager for The Nature Conservancy in Arkansas.