Hmm, very interesting. I tried it on some of my cresteds and it was fairly easy to tell the difference between adult males and females but harder in juvies--some I could tell, some I couldn't (these were old enough to pore sex so I could check my results). I tried it on some 1-2 month old hatchlings and couldn't really tell anything at all, but I may also need a better light. The younger ones were much harder just because they are so small though--it's hard to see much at all with that small of an area, but again maybe a different light would help.

It should work on leos too, but it's really not as necessary with them since you can easily pore sex them by 4 weeks of age.