The green iguana (Iguana iguana) is a popular pet in the United States for its generally docile nature and abundant availability. While most children will not be too picky when selecting a baby iguana, others will be curious to know the gender of their new pet. Unfortunately, the gender cannot be externally determined until the lizards reach about 2 years of age, and even then it can be somewhat difficult without other iguanas to compare it to.
Check out the femoral pores. These are small, bubble-like bulges in the skin underneath the back legs, forming a chain. In males, the pores will be much larger and more pronounced. In males, you may notice small plugs emerging from the pores during breeding season, which are theorized to scrape along the ground and mark their territory.
Look for fatty bumps below the eyes. In males, there will be a chain of small, fat-filled bumps below their eyelids extending back to their ears. In females, these bumps are absent.
Examine the anal pore between the base of the tail and the end of the abdomen for hemipenes bulges. In males, you should see two symmetrical bulges underneath the skin near the anal pore, known as the cloaca, where they store sperm. Females lack this bulge.
Consider the body and head size. Females have smaller heads and slimmer bodies than males, with males having particularly large heads and wider, bulkier bodies.