Full transparency: I REALLY dislike these little events where you need to collect an item to send characters out to do something. REALLY REALLY dislike them. I only play to get the happiness and then stop.
That being said, I'm sitting at 23 birds right now with three characters out collecting more (and lots of characters getting the tokens). I think it's possible, just a PITA.
Same for the bees. I'm up to seven done with one character out getting another bee. Once I'm done with the birds, I'm going to focus on the remaining bees I need for happiness and then stop. Again, possible, just a huge PITA.
And, again for transparency, I have a full time job, a fiance, a house, a dog and wake up in the middle of the night to play.