Questions about my 'Too

Hi all, I am new here, and new to owning a large bird. I have been arount 'Toos before and Ive always been good with birds in general because I believe theres a calmness about me they enjoy, or at least it puts them more at ease.
Which brings me to Zahzu, our recently inherited umbrella Cocaktoo. Yes i know thats strike one. This is his third household..poor thing. I know 'Toos are very affectionate and usually choose just one person to be close to, but this bird has been bounced around so much in the few short years of his life I am wondering if hes not been scarred emotionally. He seems to love me...and I do mean love, and hes already exhibiting the signs of jealousy of me around others, such as my son and wife. He will attack my son on sight if hes not in his cage, he will sit with my wife if I am not around, but doesnt stand for us being close at all. If she is holding him and i get close, he immediately comes to me and ruffles himself up and starts squawking at her. This morning I came in from taking my son to school, and he was wired, jumping and flapping in his cage, squawking here and there and punctuating it by saying "hello" which is one of the few words he knows thus far. I got his food ready and opened his cage, and he climbed out of it and onto the door very quickly. What happened next caught me totally by surprise. He launched himself onto my shoulder and bit my ear...and hard. Put a nice hole right through the cartilage. This shocked me and naturally i jerked away and he wound up flapping his way to the floor, and then he chased me out of the living room biting at my feet. I wound up grabbing my sons remote control car and using it to chase him back to his cage, having to keep my feet up off the ground lest my toes became chew toys. After about a half hour he calmed down and I was able to feed him and take him out of his cage. He cuddled right up to me like nothing in the world happened. Which leads me to another bit of strange behavior he has. He likes to nestle against my chest and get petted, but after a bit he starts making these little coughing sounds, and bouncing just a tiny bit. I thought somthing was wrong with him, but he only does this when I hold him. If anybody can help me with figuring out these behaviors, I would appreciate it a lot. Thanks

Welcome to the forum! Zahzu is exhibiting sexual behavior. When he is on you do not give in to close cuddles as this stimulates him. The noise he is making is panting and he is masterbating on you with his movements. It would be best to keep him just on your arm for now. Absolutely no petting below the head and neck as this is also stimulating. If he continues put him back for a while and try again. This is breeding season for Toos.
As far as biting you, He was probably very excited about you coming home. You immediately opened his cage and he took advantage of this and took the leap. His overstimulation caused him to react and bite you. It is best to never open his cage unless he is reserved. Give him a treat between the bars, away from the food dish and keep him occupied while you remove the cup and feed.
Make sure he has plenty of toys and foraging opportunities. These will keep him busy and burn off excess energy. It is extremely important to never allow him access to the floor. This is a common problem with a lot of male Toos and other larger parrots.
It is my recommendation that you never allow him out of his cage when your son is present. These birds can do extreme harm when they bite. It would help to get your son to play quietly near his cage so that Zahzu slowly becomes used to him.
Your wife should spend some time sitting by his closed cage, reading, talking and singing to him. Have her drop a very favorite treat in his bowl throughout the day. With patience he will learn that she means no harm to you or him and will accept her.
Please do not ever allow him on your shoulder or near your face. It takes a long time to build that special, safe bond. You may never fully be able to completely trust Zahzu, but you can have a very special companionship with him.

I agree with Greycloud completely. I have a female umbrella. She happens to love EVERYONE, which is great, but we are careful during breeding season, as hormones are running high and behavior is a bit off.

You are probably seeing why he was rehomed. Unfortunately this happens a lot (rehome) with too's.

Does anyone know how long their breeding season lasts?