I received a call in 2014 from distant family asking if I would take a parrot since his owner had passed. I had been looking at parrots and was trying to determine what type of parrot I would bring in our home for months when this call came in. This parrot was at the city pound, the police had to be involved in the death, very sad situation, but no fowl play.
When we went to pick up Buddy, he was in a police, mechanic bay office. They put him in a space separate from the other animals. Buddy is now a 25 yo parrot, he spent 20 years with his previous owner, a strong relationship. As now known as typical Buddy, he said "Hello!" as we walked in to see him. After we put his cage with him in the back seat of our double cab truck, we went to Sonic to get drinks. I heard a noise in the back seat, turned to look and found Buddy with his head pressed against the bars in a very clear "scratch me" position. I scratched his head, he let me! Since then he and I have built a fast, strong relationship. I let him control the pace.
I learned later how amazons are "quirky" and felt honored that on the first day in minutes he wanted a head scratch from me! I brought home an Ekkie in January 2015 and one major difference between them is I can shovel food in Buddy's bowl with no issue, Venus (the Ekkie), I can get one hand full in and any other attempts result in biting. Buddy has never hurt me, never drawn blood. I pushed him to take a bath and he bit me holding on gently but squeezing harder the longer I tried to coax him to get wet. He settled in fast, loves his cage (he's a cage potato), but loves to shower with me, not on his own and we have a great relationship. I think in Buddy's case he was so lonely since his owner was so sick (stroke victim with paralysis) and she couldn't interact with him daily on her own like they had been, he was looking for that link.
Buddy doesn't say much but I've talked to several people that know him and he has a robust vocabulary, he just doesn't share or talk. We get Hello for sure, we've gotten a wow and when my niece graduated in 2014, we were watching the graduation via a feed and he was repeating names as they called them out and they walked to receive their diplomas.
So as someone on this site said, a rescued parrot is like a treasure chest, you just have to find the right key to unlock them to find out what they know. Time and patience helps too. Buddy easily adjusted to me but I think that was a one off since he had been lonely and his basic needs met for several years. They do look for connections based on their previous relationships. The police told me that when they arrived on site that Buddy had no food or water for several days. They immediately gave him water which he took with gratification, then he took seed. His owner would share her dinner with him so he was use to real food, but towards his owner's end highly and easy processed foods like I understand he loves macaroni and cheese. I've never given him macaroni and cheese. Each bird is unique depending on their previous relationship but you can open new doors for them and strike up new relationships.