just a question, might be just wishful thinking but about the head size thing to tell the difference between male and females, is that from when they are young or does it develop later on? the reason i ask this is because ive found a pretty good way of sexing (i hope!). if you measure the width of the head with your fingers and compare it with the length, on the females, both measurements should be about the same but in the males, the length is quite a bit longer than the width. works for me! is this reliable?