Females are several ounces heavier than the males. You'll want to know the age of the birds he's selling and you prefer to get them as 6 to 8 week olds. Fertility and egg laying drop off dramatically at the one year mark. You'll be looking for breeding sock, not freezer food. I prefer pharoah coloring because they can be sexed by plumage coloring and pattern. A pharoah colored quail will be similar to the quail in my avatar. Pictured is a female, note the speckled breast... a male pharoah will have a creamy breast with feather coloring that has a distinct gold/orange/rust color at the edge of the solid cream belly. If pharoah isn't available to you, you can vent sex them. Hold the quail in your hand as I described in the butchering in my earlier post, and flip the bird upside down. With dominant hand, move the feathers away from the vent and give the vent a very gentle squeeze. A mature male should have a red bulbous organ at his vent, a less mature male may or may not have the bulb yet, but a very gentle squeeze of the vent should cause white "foam" to come out (his sperm). If the seller says that the pullets are laying, then you will be looking at the shape of the bird's vent. Tight little donut vent, not laying. Oval vent, or a long slit looking vent, indicates a layer. If you're uncertain of gender, select a different bird. You want ONE cock, and the rest pullets. Otherwise you'll have one too few girls, and one too many meat birds... the boys WILL fight, sometimes to the death, for the right to mate. Breeding stock is too expensive to buy too many males.
If he's selling straight run chicks (up to a week old), then you'll want to buy twice as many as you intend to end up with. The price on them should be significantly less than 6 or 8 week old birds, and their gender will not become apparent until they are closer to 4 to 6 weeks old. Assume that half will be meat birds (excess males). Quail are incredibly hearty, even as chicks... much more so than chickens, so this could be an option for you.
