Can my pellet gun kill a pigeon, crow or a squirrel?
Yes possible, but also air guns more likely injure the animal rather than kill outright and cause suffering. Feathered creatures are harder because they are protected to a degree with their plumage and though the pellet could penetrate it would not often be a clean kill. Even if you finished them off they would suffer and be frightened terribly but some would get away but die later of their injuries you caused. Why not practice on non living targets such as accuracy tests or join a shooting club which you can compete your skills with other enthusiasts in a safe and acceptable manner. To indiscriminately kill and harm the creatures of the natural habitat for fun is ecologically wrong and not demonstrating your character at it’s best.
It has the potential to kill them, but that’s not exactly a high fps or large pellet. It would certainly kill a small animal like that if hit in the head, although you may end up just seriously injuring them with a body shot, in which case you’d need to take a second “mercy” shot, which isn’t exactly pleasant. It can be done, if done right, but I would recommend getting a higher power pellet gun, such as a break-barrel with 900+ fps, although some pump guns can get up to that and beyond. In short, just try to hit it right and it will do the job.