[rockstarcow]

I have just gotten a new cockatiel and his behavior is still unfamiliar to me.
We purchased him about a week ago from a pet store, according to the store the bird was a handfed baby, he was with 3 other birds at the time and was at the shop for about 3 weeks before we got him. According to the shop he is about 4 months old ( we don't honestly know if it male or female). He let us hold him in the store, there was quite a lot of people in the store so he was nervous, but was able to be held by me and another person with me.

We brought him home and naturally he was frightened, we left him alone for a few days before we tried taking him out of his cage, we took him to the vet and she said he was healthy, the vet was also able to hold him after a bit of coaxing. She said that since is he allowing us to hold him that he should be tamable within a few weeks.

So here is my question/problem. He will not let us take him out of the cage or touch him at all. I can get to the point right before I can touch him before he turns aggressive and bites. He also gets very vocal in the evenings (around 10:00 pm), the vocalizing doesn't bother me, but I want to make sure that it is normal behavior, he will make different noises, and usually his crest moves towards the back of his head during this period, not in an aggressive manner though(still slightly raised in the back). I can give him treats though the bars of his cage, and I can also get him to eat out of my hand.

How can I get our cockatiel to let us touch him without shattering his trust in us? I understand that patience is going to be essential when working with our tiel, but I was just wondering if there are any techniques out there that I haven't picked up, and if his behavior sounds like he is warming up to us, since this is my first tiel.