Paul Rhymer had fun with the "first robin of spring" idea. So did Don Quin of Fibber McGee and Molly.
I thought it was all a big gag... but then, I got the idea to look this up in the Daily Pantgraph (now known as The Pantgraph), the Bloomington newspaper.
I'm not into spending wallets of money, so I can't access the articles there (by the way, all newspapers should be ashamed of themselves for charging to search out and retrieve old articles., don't you agree?). Anyway, after tip-toeing through their system which is designed for me to find what I want but not actually show me anything, I found enough to convince me that spotting the first robin of the spring is indeed a big deal in Bloomington, Illinois. I did not fidn out what the reward or benefits are/were, however, getting one's name in the paper seems to be fitting (and I did see such evidence).
So, there's that!