Since the first time I read through this thread, I think I realized a possible reason why I see no problem with the wood duck and some people do: I suspect everyone who thinks the wood duck is too much, usually plays with "ban powerful bird cards" enabled. Without those other 4 in the deck, the wood duck stands out more.
However, I _never_ play with "ban powerful bird cards", I think doing so makes for a significantly poorer game. When all those cards are in the game, you have more of a chance of getting one of them, even if another player got one also. And also, when those cards are in the game, the wood duck doesn't stand out as much - it's another powerful bird among a bunch of powerful birds, and another possible counterbalance.
Powerful birds are not determines of the outcome. Here's a recent game in which I beat a pretty good player (mid-200s ELO) who got _both_ a raven and a killdeer near the start of the game, and I had none of the powerful birds (not even a wood duck): https://boardgamearena.com/10/wingspan?table=386084916
And another recent game where they got a raven in round 1, I got no powerful birds nor wood duck the whole game, and I won: https://boardgamearena.com/table?table=385349368
If you play a bunch of games, it's also very "fair" in that your odds of getting some of these cards are just as good as the odds that other players will. It's a much more interesting - and, I think, fun - game with those cards. And if you have the 4 "powerful birds", it's definitely better to have the wood duck in the game along with them.
However, I _never_ play with "ban powerful bird cards", I think doing so makes for a significantly poorer game. When all those cards are in the game, you have more of a chance of getting one of them, even if another player got one also. And also, when those cards are in the game, the wood duck doesn't stand out as much - it's another powerful bird among a bunch of powerful birds, and another possible counterbalance.
Powerful birds are not determines of the outcome. Here's a recent game in which I beat a pretty good player (mid-200s ELO) who got _both_ a raven and a killdeer near the start of the game, and I had none of the powerful birds (not even a wood duck): https://boardgamearena.com/10/wingspan?table=386084916
And another recent game where they got a raven in round 1, I got no powerful birds nor wood duck the whole game, and I won: https://boardgamearena.com/table?table=385349368
If you play a bunch of games, it's also very "fair" in that your odds of getting some of these cards are just as good as the odds that other players will. It's a much more interesting - and, I think, fun - game with those cards. And if you have the 4 "powerful birds", it's definitely better to have the wood duck in the game along with them.