Back when I was younger (not much) and more naive (very much) I learned the hard way that a wing-clipped pigeon is sometimes not the best retrieving tool for a young dog.
We were working on steadiness in the face of running birds, and that part we’d finally gotten down pat. But as the saying goes, “perfect practice makes perfect,” so I concluded that a retrieve should finish the drill.
Boy howdy and call me Betty! Even a wing-clipped bird can make quite a dust cloud once a dog joins the tumble. A live, unencumbered bird is a different animal than a dead one. I doubt you’d call it “fighting back,” but those pigeons put up considerable resistance: Beak-and-nail and wings akimbo, which was the primary obstacle, it turns out.
For a while, the outcome was in question, but eventually, retrieves were made and culinary kudos handed out to canine participants. But not without some confusion.
Later sessions better simulated the “dead bird” scenario, with wings wrapped to avoid head-in-the-mouth and even less stable retrieving grips. We’re much happier now.