Buck,

We'll try to answer your second question first. Preening is a bird's way to "spruce" itself up. They clean and tidy up their feathers by taking oil from the oil gland (located at the upper base of their tail) and meticulously groom their feathers. Sometimes during the molting period, they will remove a feather or two, so preening shouldn't be confused with plucking.

Since you have only recently acquired your cockatiel, the biting and pulling of feathers could be associated with the cockatiel being nervous or frustrated or he could have possibly gone into a light molt due to the change of homes. It coul also be symptomatic of other more serious problems.

We suggest you have the bird checked by an avian vet to eliminate what might be unnecessary concern and to insure the best interests of the bird are tended to.