different breeds have different characteristics ..... what gives a good indication with one breed does not always apply to another.
That's so true. Usually best to play it by ear and a little while down the track you'll be giving advice rather than asking for it.
Pekins are very easy and mine crow by 4 weeks
What are you feeding them?! I have given mine kelp as a regular and find it necessary to cause full expression of genotype in pheotype, as well as recover latent instincts and good genes that were bred into insignificance, but I've never had one crow that young! I have had them hatch at 14 days, and try to mate at 4 weeks though, but that only happened for a little while then stopped and I'm none the wiser. Do they crow properly, as in not make those strange strangled noises some of the young ones start with?
Which brings me to the reason I chimed in... If you give kelp regularly they'll show gender reliably in their first week, via red and enlarged crests as compared to their sisters. But it can take a year before the hen's amped up enough to produce the real crackers of offspring that show the benefits of the extra nutrition. I find that when most pet/animal food companies claim 'complete nutrition profile' they just mean they passed a lacklustre test that involved the animals not dying outright of nutritional deficiency, which doesn't actually mean they had a good, problem-free and long life on the foodstuffs offered.
when our cats sleep on their backs infront of the fire, the boys pull their back legs up and the girls let theirs go straight.
Maybe due to the broader back the males can rest easy whereas the females would roll over? Some female cats are broad too though... Had a tom who would enter fights from that position; he could actually run backwards on his shoulderblades, at quite a pace. Hilarious.