Very possibly a form of communication. Try to define when and what is going on around your Senagal. Are you coming closer or moving away.
As a Parrot begins to adjust to a new home, they start with contact calls. Try returning the sounds with a few short word responses, like I'm over here (if you are out of the room) or like communications that tie to what you see around you and the Parrot.
If possible, contact the last owner and ask.
This will also, get your Thread bounced back up the board and likely a Senagal owner will respond.
Thank you SailBoat. No way to contact last owners. He started doing it after I set up a stand near my computer, maybe he's trying to tell me he wants up? I'll keep trying to figure it out.
My Hawk Head squeaks when I'm trying to pick her up and she doesn't want to go....kinda like complaining. Happens when she's in a loving mood and doesn't bite. Other times when she doesn't want to be picked up she puts her crest up, hisses and bites but she's beyond the stage where she bites very hard, just a more forceful complaint.
Though we don't do this anymore, when she's horny and cuddly she'll squeak when you cuddle her or rub her belly so that squeak is more of a mating one I think....they all sound the same, just a squeak.
She doesn't squeak just sitting there so I'm sure it's not the same behavior but I thought I'd share.
Congrats on the senegal; others with one may chime in more. They're very intelligent birds and learn a variety of training methods. The squeaky sounds could just be a way for him to communicate and as SailBoat says, establishing a similar sound or knowing you're at a close distance may help. As a good sign that he's friendly, there could be more indications that he could be content as he adjusts.