Parrots pick their owners. If they are matched up with an owner they do not like they can spend their entire lifetime in a miserable situation where no one is happy. They have individual personalities and personality preferences and once they bond they can become heartbroken when they lose their person. We rehab and rehome parrots all the time and most do very well with the change but there are some, usually the ones who have been very well loved, who do not adapt as easily - especially congo african greys. Parrots can live up to 100 years so making a commitment to them and also a will for their future is important for bird owners.
Our indian ringneck is a sweety (with me) and such a beauty. I think ringnecks have some of the greatest personalities out of all parrots. Lories are extremely messy if fed lots of fresh fruits and veggies, somewhat messy being fed a powdered diet, and not very messy when fed soaked pellets. Any type of pellet is dangerous for them to consume though as their digestive tracts are longer and tend to get damaged when grains and harder to digest foods are consumed. Lories are also moody and owners quickly learn that their birds frequently have mood swings and decide to attack at random. They are easily over stimulated but very demanding and when they bite they bite hard. They are certainly one of the more advanced parrot species and even tend to challenge those who do well with other species.
Although macaws may have the largest beaks, cockatoos probably have the worst bites. A macaws beak crushes - usually leaving a bruise and a welt. Cockatoos have compact beaks that are designed to apply pressure and then tear. They pierce the skin producing deap puncture wounds and sometimes tear the flesh upon exit. They are probably the most difficult species to work with as they have high hormone levels that cause biting, plucking, screaming, and other behaviors (though the smaller species can make wondeful pets). Cockatoos are the loudest species of parrot and can and will scream to be heard miles away. Teaching them not to scream, bite, and chew is like teaching them not to be a parrot, which is just not possible, so cockatoo owners have to accept these behaviors to have a successful relationship with their parrot. Macaws tend to be a bit more mellow and are wonderful, loyal, and devoted when they bond. They are very loud also and very challenging, but not nearly as much as a cockatoo. Sadly, we work with macaws and cockatoos daily who were purchased by well meaning families who simply had no idea what they were getting into.
I'm sorry for the one whose sister lost an amazon. A very sad situation. we clip our birds so that accidents like that do not occur. Amazons are well known for protecting their nest by dive bombing intruders to ward them off. Dogs are well known for snapping at and/or capturing small fuzzy or fesathered creatures. Both animals were following their instincts but the parrot will always lose if the owner does not keep them out of harms way. This is why, even though Brutus hasn't shown any interest in playing with and/or hurting any of the birds, you just never know and dogs are predators and parrots are prey animals.
Sorry to ramble. I get kindof caught up in birds. They are my special love.

-Anna