You need to earn your bird's trust so you can both have a good relationship.
I just got an African grey. He’s 6 years old and had feather picking problems, but he’s slowly growing them back since I got him. My problem though is that, although he’s sweet to me and I can pet him, hold him and carry him, he seems to be violent toward my mom. I live in the same house as her, and she visits him everyday, but he just won’t warm up to her. When I first got him he seemed OK with her, but she also tried to force him to step up, which I had warned her not to do. About a week later, I bought him some foot toy balls that jingle. She tried playing with him and threw the balls on the top of his cage for him to retrieve. He threw them back roughly at her. After that he wouldn't step up on her and bit her every time she tried to pet him. She says he bites her and then holds on, making marks.
Even when I carry him around and go near her, he'll give me a warning bite if I get too close to her. His favorite treat is cherries and everyday she tries to feed them to him, but he literally throws them back at her. One time he started bouncing his head rapidly and, when she tried to pet him, he went to bite her and then made a raspberry sound. My sister, who is a little more timid toward my birds, can get him to step up and even pet him. How do we gain back his trust in my mom?
We have a way of projecting our own emotions on to our parrots. I am not insinuating that you are mad at your mom, but the truth is that your African grey may not be angry. He may just be uncomfortable with her. This may be because she did something that made him lose trust in her. The fact that he won’t take treats from her most likely means he doesn’t trust her.
The majority of the time, biting behavior doesn’t start because a parrot is aggressive or mean; it starts from fear or confusion. The fact that your grey likes your sister gives me a good clue as to what is going on. A person who is timid (without being afraid) is not going to present any kind of threat to the parrot. Parrots are prey animals and can be very sensitive to any threat whether it is real or perceived.
The element of territoriality may also be influencing the grey’s behavior. Greys can become one-person birds unless people work with them so that they form a bond with several people in the family. Your mother should try working with him in a neutral room. This is a room that he is unfamiliar with and where he can’t see his cage. Take him into the room and place him on a T-perch or the back of a chair. Place a few of his treats where he can see them but can’t reach them.
Your mother can then go into the room. At first she should just ignore the grey, making little or no eye contact with him. She can sit and read a magazine and then offer some treats to him without making direct eye contact. Repeat this exercise until the grey is comfortable stepping on her hand and she can bring him back into the room with his cage. In a situation like this, submissive, calm behavior from a less-favored person will gradually win the bird’s trust and affection.
Want to learn more about African greys?
All About African Grey Parrots
African Greys: Myths & Facts