A few traits I've noticed over the years...
First off, don't bother with swinging pennies over their heads. Don't bother with dangling them up side down. Don't bother with throwing towels over their head or any of that other junk, because it doesn't work. Your best indicator is personality combined with physical signs.
I won't cover autosexing breeds because those are obvious. In breeds where you have to make your best guess, you'll often start seeing some differences at two to three weeks. It won't be reliable, though, and often you'll miss several cockerels if you try selling off all the cockerels at this age. The first sign is often a different, more 'cocky' personality. These are the chicks that have no fear, that think brooder tops are put there to challenge their flying skills, and look you in the eye as an equal. Yes, there are indeed some hens that act this way as youngsters, but they're not near so common. I had one bird that started sparring with me at 24 hours old. Yep, he was a cockerel, and a handsome one too. Sometimes you will see some chicks with thicker legs than the rest. Those are also pretty likely to be cockerels.
At a certain age (I don't know what, sorry---I don't keep track of how old my birds are very well. Maybe a month and a half?) you'll start being nervous that all your chicks are little cockerels. Even the females have some shiny feathers poking out by the earlobes, and their combs start to develop faster. The best way I have found at this age is to look at the comb only. This is tough in a few comb types, but generally the males have more substance and base to their combs than the females. They may or may not be getting a tinge of red to the comb by now. They still don't have sex feathers visible.
At another later age (that I still don't know, sorry. Two months? Three?) you'll see them start to fill out a bit. They won't have quite as many pinfeathers, and whilst they still look like chicks they aren't the little fluffy cuties you brought home from the feed store. The males should have much larger and reddish combs at this point, but in case you're still wondering then you can go checking for sex feathers. Right around the saddle area there'll be some feathers coming in, and if they're pointy and lustrous, you have a boy. I don't think the hackle feathers are near so reliable but to some extent they have the same point and lustre.
A note on wattles. On some breeds the comb stays quite small and near invisible all its life. On these, their wattles (if not bearded) are a good indicator. If they start growing and reddening before the bird looks mature enough for them, then that's a cockerel. So, to wrap up and repeat: personality, comb size, wattle size, leg size, sex feathers.
I am sorry I couldn't find any pictures that illustrated what I was trying to say, and I also wish I had kept track of ages. I find that sexing them sooner than they crow or lay is something that's hard to be taught by anyone except the birds themselves. Keep observing your birds, your breeds, and eventually you'll be able to be pretty accurate.
Also note that all of these things are generalizations and have to be when talking about living creatures. I myself have had several birds that I could have sworn were one sex and they were actually the other.
First off, don't bother with swinging pennies over their heads. Don't bother with dangling them up side down. Don't bother with throwing towels over their head or any of that other junk, because it doesn't work. Your best indicator is personality combined with physical signs.
I won't cover autosexing breeds because those are obvious. In breeds where you have to make your best guess, you'll often start seeing some differences at two to three weeks. It won't be reliable, though, and often you'll miss several cockerels if you try selling off all the cockerels at this age. The first sign is often a different, more 'cocky' personality. These are the chicks that have no fear, that think brooder tops are put there to challenge their flying skills, and look you in the eye as an equal. Yes, there are indeed some hens that act this way as youngsters, but they're not near so common. I had one bird that started sparring with me at 24 hours old. Yep, he was a cockerel, and a handsome one too. Sometimes you will see some chicks with thicker legs than the rest. Those are also pretty likely to be cockerels.
At a certain age (I don't know what, sorry---I don't keep track of how old my birds are very well. Maybe a month and a half?) you'll start being nervous that all your chicks are little cockerels. Even the females have some shiny feathers poking out by the earlobes, and their combs start to develop faster. The best way I have found at this age is to look at the comb only. This is tough in a few comb types, but generally the males have more substance and base to their combs than the females. They may or may not be getting a tinge of red to the comb by now. They still don't have sex feathers visible.
At another later age (that I still don't know, sorry. Two months? Three?) you'll see them start to fill out a bit. They won't have quite as many pinfeathers, and whilst they still look like chicks they aren't the little fluffy cuties you brought home from the feed store. The males should have much larger and reddish combs at this point, but in case you're still wondering then you can go checking for sex feathers. Right around the saddle area there'll be some feathers coming in, and if they're pointy and lustrous, you have a boy. I don't think the hackle feathers are near so reliable but to some extent they have the same point and lustre.
A note on wattles. On some breeds the comb stays quite small and near invisible all its life. On these, their wattles (if not bearded) are a good indicator. If they start growing and reddening before the bird looks mature enough for them, then that's a cockerel. So, to wrap up and repeat: personality, comb size, wattle size, leg size, sex feathers.
I am sorry I couldn't find any pictures that illustrated what I was trying to say, and I also wish I had kept track of ages. I find that sexing them sooner than they crow or lay is something that's hard to be taught by anyone except the birds themselves. Keep observing your birds, your breeds, and eventually you'll be able to be pretty accurate.
Also note that all of these things are generalizations and have to be when talking about living creatures. I myself have had several birds that I could have sworn were one sex and they were actually the other.
That said... I'm completely spoiled and have autosexing breeds for the most part and will going forward. Here are some photos that show a bit of the 'attitude' in chicks that are just a day or two old:
