Same time as the femoral pores start to develop. It's all to do with the hormonal increase and genetics. Some males will have extremely large jowls while others are not quite so pronounced...and some males take on very female characteristics and have no jowl formation at all. The are usuallu omega iguanas that don't want to draw attention to themselves by the dominant males. It's even said that they produce a female scent. Very alpha females will also take on male characteristics...and this is why visual effects alone are still not a 100% gaurantee. The only positive way to know for sure without a blood test or being probed by a qualified herp vet is if they flash the hemipenes, leave seminal plugs or lay eggs.
Well duh as my son would say ;D. I know that already i was just asking as a generalized question, because I have noticed before that some Iguanas have massive jowls at a younger age than others. What I was asking is do you guys think that there is an average age for the average male iguana when they start forming.
Last Edit: Jan 29, 2007 5:59:25 GMT -8 by MasterYoda