You would have to be pretty good to kill just about any animal with a thrown knife. You would most likely just wound the animal. Any larger animal might just get a severe wound, and run away with your knife. Sounds like a waste of effort, and could land you with charges of animal cruelty as well. Why not use a bow and arrow? people stopped using primative weapons when better ones were invented.
Also, Pigs are hunted with knives, but the knife is used to stab the pig as it is held by dogs, it is not thrown. As far as killing birds, If it was legal to hurl a projectile and kill birds (I kind of doubt that it is) a rock thrown or hurled with a sling is going to be a better weapon than a knife. Again a Bow is a better bet. Of course in a survival situation, all bets are off as far as legality goes, but I would still prefer a bow (even a spear) to a knife. Who carries throwing knives anywhere they are likely to be in a survival scenario?