You'll need to work with your Jenday on a daily basis just like you have to with birds that are not hand-tame, which I'm assuming your Jenday was not, or at the very least he may have originally been hand-tamed and he hasn't been handled in so long that you have to start over with him.
It's good that you can at least get near him and that he'll step up onto a perch. That's further ahead than most. So what you need to do is do hand-taming training sessions daily with him. You start by opening his cage and simply just placing your hand inside the cage and leaving it there for a good 15-20 minutes. Don't move it, just let your hand rest inside his cage. You'll do this for a week or so, every day for a good 20 minutes. Each time you ideally want to be able to get your hand closer to your bird without him moving away.You may be able to go a bit faster than with a bird that you can't even get near, but you definitely do not want to rush it. The next step is to use a treat that he likes, millet sprays always work well, and again place your hand inside his cage but now hold a millet spray in your hand and try to get your hand close enough to him that he will eat out of your hand. Then the next step is holding the millet in your hand but sticking your index finger out and placing it above his feet, gently touching his belly with your finger. Something about touching the top of their feet/belly with your finger causes them to step up onto your finger. He will probably step up and back off right away for a while, but eventually he'll stay on your finger. Then the next step is getting him to step up onto your finger and just keeping him on your finger inside his cage for 15-20 minutes. Then the next step is trying to slowly move your hand with him on your finger out of his cage. Once you accomplish this and are able to do it most times with no issues, then the next step is getting him to step up onto your finger outside of his cage, anywhere you ask him to. All of these steps take patience and work every day for at least 20 minutes a day, and each step will take at least a week or more before you will be able to advance to the next step. It works, but it's a long process. As I said you're already ahead though.
I have a friend that has worked at Petco for years and is the bird person at her store, and I asked her about the "Hand-Fed" birds they started getting (so says the little description card on their cages). Basically the bottom line to their "Hand-Fed" birds is that it is totally dependent on which "Vendor" the bird comes from, and how long the bird has been passed from store to store, because some stores are very good at handling the birds daily to keep them tame and some don't ever touch them or pay any attention to them. They use a handful of large bird-mill vendors, and they pay extra for "Hand-Fed" birds from the bird mills. There are two vendors they use the most, "Barney's" is the largest, and she does not like them at all, the "Hand-Fed" birds are not usually at all tame. The second one they use the most she says is wonderful and the birds really are very tame and in very good health, but I can't remember their name...And then there's their policy about time, the initial store will get the baby bird first, and they will keep it for 2-3 months. If they don't sell it after reducing the price 25% in the beginning of the 3rd month, they send the bird to another store and they start over at full price again. Some birds are there for well over a year, at which point they are told that the hatch certificate is "lost" or they're "waiting for the "breeder" to send it to them", but it never comes. This way they can lie about their age...It's pretty awful.
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