Help sexing maron chick
Can I have a photo of the body in profile. Age of bird is helpful too. From this one head shot the bird has a large comb and seems to be coloring but not red by any means. Large for suspected age. Lets see the honking legs and then I'll say it's a cockerel. My guess is near 3 weeks age.
If you've other birds to see in comparison it's easier to sex. Honking legs are males, will also appear longer. Thinner legs and body set lower and more horizontal are females. By the large comb at 3 weeks my guess is he has large legs and stand rather upright. You'll see red in comb in few weeks. Single comb pullets wont show any red until nearing point of lay +/- 20 weeks.
I'll go pullet with this one so far. Being feathered leg it's hard for me to look at them. This is something you can do with all the chicks regardless of breed. Take for instance that Barnevelder which could be a cockerel. Check those legs to this one and others. Legs are legs and though different breeds will be heavier or lighter the overall effect of leg to body size and stance will push you to pullet or cockerel with just that one clue then add up the others and see which side has more weight of evidence.
Let's look at this Marans. The comb isn't huge though I'd like to see a pullet this young with next to nothing. Just because that's easy. Wings are fully feathered in. This to me is a strong indication of pullet. Now breed to breed there is some variation of timing but pullet wings feather in much faster than cockerels. For three weeks if a cockerel I'd expect half that of wing feathers. The stance of bird is not upright. Again this hedges the bet to pullet. So back to the check list: comb- neutral, legs-have to be there to see them, stance-pulletish, wing feathering- strong pullet. With the evidence of two photos only (not actually there to see it) I'd say it's pullet. And that in general is how it's done. Some birds are obvious others not so much and this is not breed specific. Within same breed you can be definite at early age on sex for well over 80% of them but there will be a few that keep you guessing. Weighted feeling of all the evidence will sway you one sex or the other. Being these are single comb birds the cockerels will tell you at 4-7 weeks by red showing in comb. That's when the guessing is over and you know for certain.
Give it a go yourself, write down pros and cons for each bird for your guess of sex then go back in 3 weeks to see how you did. It may surprise you how accurate you are or at least give you a learned base to judge in the future. You could be a natural at it or it will only take a few batches of birds and will get good at it.