The crystal lizards themselves are certainly hand placed, though I'm not sure if their actual drops are. Be wary of "titanite fever" though, as sometimes their glittering placement can lure one into areas quite hazardous for one's health.

If you've been following my posts and DeepO's responses, you'll know that the bird does have a specific purpose. However, admittedly I tried attacking it once yet after some time and damage it merely flew away, only to reappear again whenever I revisited Firelink.