Screaming and feather plucking are often the result of bored and frustrated birds. Parrots are incredibly smart, and, unlike dogs and cats, are not domesticated. In the wild, they spend a large part of their day foraging for food. They use their incredibly loud calls to communicate with each other from miles away. This is especially true for the larger parrots, like macaws and cockatoos. Almost all Psittacine birds (AKA Parrots) form monogamous pairs that mate for life.
In captivity, birds are often kept in a cage and do not have the opportunity to behave the way they would in the wild. They often can’t forage for food the way they would in the wild, and they can’t search for a mate. Many are left with very little in their cage to keep them occupied, and they are often alone for several hours. As a result, many parrots become bored and/or frustrated and start screaming a lot or plucking at their feathers.
To prevent these unwanted behaviors, parrots should be allowed several hours out of their cage everyday to exercise their wings and spend time with their owners. They should be part of their human "flock." They should also be supplied with a vast assortment of toys and other items that encourage appropriate chewing and foraging behaviors. The more time the parrot spends doing these appropriate behaviors, the less time the parrot has to get bored or frustrated. Parrots will still scream, even if they are perfectly content. It’s perfectly natural for them. The best thing the owner can do is to encourage the screaming at appropriate times.
Biting can be caused due to fear or inadvertent positive reinforcement by the owners. In the wild, parrots do not typically bite each other. Biting is not a natural behavior, but parrots do naturally use their beak to climb around and to forage. As a prey species, parrots can be flighty. If they become suddenly startled, they might latch on to whatever is closest to them…an ear, hand, finger. They might also use their beak to grab on to a person to help balance themselves. Some people also use their fingers as toys with young mouthy parrots that don’t have the bite force of an adult bird; eventually, the parrots might bite down harder than expected. A dominance component can also play a role in biting, as parrots are also more likely to bite if they are able to perch above their owners. If the person getting bit responds by jerking his or her hand away and yells at the bird, it actually encourages the biting behavior.
To prevent biting, it is important to not put the bird in a situation where it might bite and to not overreact in the event that a bite does occur. If at all possible, parrots should not be allowed on shoulders. They should also not have perches that allow them to be taller than their owners. Parrots displaying hormonal behaviors during breeding season should be handled carefully because they can become more aggressive during this time of year.
If these inappropriate behaviors become established, behavior modification is often used to try to eliminate the behaviors. If behavior modification alone is not successful, behavior modification drugs such as fluoxetine can be added to the treatment plan. While all of these inappropriate behaviors are commonly related to the above circumstances, medical issues should always be ruled out as causes.
This article covers inappropriate bird behaviors in a very general fashion. It is, by no means, intended to be all inclusive for every individual bird. Many other factors can play a role in these behaviors. Anytime a bird behaves abnormally, potential illness and husbandry should be evaluated by your regular avian veterinarian.