Ooo, when I looked for some Audubon art, I ran across this beautiful blog!
http://threesixfiveart.blogspot.com/2011/04/happy-birthday-john-james-audubon.html
And if you're in the mood, at least as I write this the Metropolitan Museum of Art's shop has some beautiful items based on his work. I found them again via a search at http://store.metmuseum.org .
It's also national Pretzel Day!