No, you cannot visually sex a Cockatiel until they are at least 6 months old, and it can actually take up to a year old, it just depends on at what age they have their first big molt, as after their first big molt you can usually tell the males from the females by the pattern on the underside of their tails (this depends on mutation, but for the most part you can tell the sex by the underside of the tail)...Females keep the stripes on the underside of their tails after their first big molt, while the males do not, they lose the stripes and just have solid colored tails. So if you want a specific sex and you're choosing a hand-fed baby, simply tell the breeder that you want to pay for them to have a DNA-test done; I sent-out for many DNA-tests on the babies I bred over the years for new owners, I'd just have them give me the money for the DNA-test along with their deposit. Most breeders are going to have a particular lab that they use, and if not, then all you have to do is choose one of the many labs online that do parrot DNA-testing, and order a test-kit. They usually cost between $20-$30, and most of them require a few chest feathers to be plucked; some places test blood, and this is easily done by clipping a toenail, putting the blood on a swab or a card that is sent to you in the test kit you order, then you just put Qwik-Stop on the nail for 10 seconds and it's done)...Either way, you want to give the test-kit you order to the breeder so that they are the one to either pluck a few little chest feathers or clip the toenail for the blood. Then they can send the test-kit back in, and in a week or two you'll know the sex. Obviously this will require you to choose a particular bird, or test multiple birds in the clutch that the breeder has, but it is cheap to do, so it just depends on whether or not you're stuck on getting a particular gender.
*****I cannot emphasize strongly enough to you how important it is that you choose a baby bird that is FULLY-WEANED when you bring them home!!!! Seriously, if there's one piece of advice about birds in-general that I could give you that I feel is more important than anything else, it's that you NEVER bring home a baby bird that is not already fully weaned...And there are numerous reasons why this is important, starting-off with the fact that ANY BREEDER who is actually willing to sell or who wants to sell their babies before they are fully weaned is NOT A REPUTABLE BREEDER, NOR ARE THEY RESPONSIBLE BREEDERS, NOR DO THEY HAVE ANY SCRUPLES AT ALL!!! By selling their babies before they are fully weaned, all they are doing is telling you right up-front that they don't give a damn about the welfare of their baby birds, nor do they care whether they live or die, all that they care about is making the highest profit possible, because the sooner the babies leave their care, the less money they spend on formula, pellets/seeds, veggies, etc., the less work they have to do, and the sooner they open-up a Brooder/Weaning Cage for another clutch for them to make money on (**usually they'll sell unweaned babies at a cheaper price, which is just disgusting)...I've not ever seen someone with no breeding, hand-raising, or hand-feeding experience who has decided to buy a baby bird who is still eating formula in order to save some money, or because the unscrupulous, dishonest breeders tell them that they will "bond more closely" with their baby if they hand-feed them, who has not had at the very least numerous health issues, illness, or death of the baby...And the alternative to you having a sick or dead baby bird is that you end-up with a bird who has severe neurological and behavioral issues for the rest of their life, because due to the person's inexperience in "Abundance-Weaning" a baby bird, they actually ALWAYS end-up accidentally Force-Weaning their babies, and all that this does is cause you a lifetime of stress, never-ending Avian Vet Visits, medications, treatments, behavioral therapy, and usually a very early death. Weaning a baby bird is nothing like weaning a puppy, kitten, rat, hamster, etc. It's just not. They are more like human babies in their behaviors, wants, and needs, so just imagine what happens to human babies who are not properly weaned-off of breast feeding, and you'll get a bit of a glimpse of what these baby birds end-up like as adult birds...they never reach adulthood, they are infinite babies...And that's if you don't aspirate them, give them a yeast infection throughout their GI Tract, burn their crop, and then kill them.
***And even more-important than the consequences of buying an unweaned baby bird is the fact that THERE IS ABSOLUTELY NOT ONE ADVANTAGE TO YOU AS THE OWNER TO DOING SO, EXCEPT THAT THE BREEDER MIGHT SELL THE BABY BIRD TO YOU FOR A FEW BUCKS LESS...THAT'S LITERALLY THE ONLY ADVANTAGE!!! Contrary to what lying, unscrupulous, irresponsible breeders will tell you, hand-feeding a baby bird is NOT WHAT TAMES THEM!!! First of all, it should be obvious to you that hand-feeding a baby bird is not what causes a "bond" to form between you and the bird, because if that was true them no bird would ever bond with anyone except for their breeder!!! But forgetting that popular lie about bonding, again, the act of hand-feeding a baby bird has nothing at all to do with taming them! It's simply the daily handling and personal interaction that the breeders have with the baby birds which tames them. This is why some bird breeders actually choose to NOT hand-feed their baby birds, yet they still sell hand-tamed baby birds...How is that possible? Because hand-feeding is unnecessary, all they have to do is block off the parents from the nest-box while they're out in the cage eating, and then they can sit and spend a good 20-30 minutes handling, petting, and talking to each baby bird, each and every day. That's all it takes to hand-tame a baby bird. It has nothing to do with feeding them formula at all. It's actually becoming more and more common to see bird breeders who advertise their babies as being "Hand-Tamed" or "Hand-Raised", but not "Hand-Fed". This is because they don't want to take the many, many risks that hand-feeding a baby bird naturally brings, nor do they want to feed the babies every 1-2 hours, including overnight, from week 2 until week 4 of age. So they simply wait until the babies are at least 2 weeks old but no older than 3 weeks old, as breeders who hand-feed do (hand-feeders pull their babies from the nest box no younger than 2 weeks old, and no older than 3 weeks old), and they start spending as much one-on-one time as they can with each baby every day, handling them, scratching them, cuddling them, talking to them, feeding them millet from their hands, etc., until the babies are fully weaned. And those babies are every bit as tame, loving, and cuddly as the babies who are hand-fed by their breeders...So when I say that there is no advantage to you buying a baby bird that is not fully weaned and you hand-feeding it, I really do mean it. There is not one advantage, yet there is almost always guaranteed to be tragedy, heartache, and often death, not to mention a lot of expensive Avian Vet bills....So if any Cockatiel breeder tries to sell you an unweaned baby bird, the best thing you can do is not only refuse that offer, but walk away completely and not buy ANY BABY from those breeders, because this is a huge red-flag that they are not good breeders, nor should you support their irresponsibility by giving them money...There are plenty of experienced, ethical, good Cockatiel Breeders who sell hand-raised baby Cockatiels that you can buy a happy, healthy, tame, loving little baby Cockatiel from...that is at least between 8 and 10 weeks old, or older...
Seriously though they are probably among the easiest of parrots to manage. My boy Fang is pretty much bonded to my husband. He also has a vast repertoire of Broadway show tunes he loves to whistle at top note, he’s a lovely boy.
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