The males defend specific areas, which usually inlude more than one female. Male Iguanas can be highly aggressive towards each other. Territorial displays involve rapid nodding of the head and, sometimes, biting and tail-thrashing battles.
Land iguanas reach maturity between eight and fifteen years of age, depending on their size.
They congregate and mate during specific periods, which vary from island to island. The females then migrate to suitable areas to nest. After digging a burrow about half a meter deep the female lays two to twenty-five eggs in the nest. She then defends the burrow for some time to prevent other females from nesting in the same spot. The young iguanas hatch three to four months later and then take about a week to dig their way out of the nest.