Being a cold-blooded reptile, much of the Santa Fe land iguana's day is spent regulating its body temperature. For many hours this iguana will bask in the sun and then in the midday heat it will retreat to the shade of cactus, rocks or trees (2) (6). At dusk, the iguana crawls into an underground burrow in order to conserve heat during the cooler nights (2) (6).
While young land iguanas feed primarily on insects and other arthropods, this reptile becomes more herbivorous with age, with adult land iguanas eating mainly Opuntia cacti (5). They eat both the fruit and the spiny pads of the cacti, often without removing the spines, although they can sometimes be seen scraping the spines off with their claws (4). The succulent cacti provide the iguana with much needed moisture during the dry months in its arid habitat (6). Adult iguanas supplement this plant diet with some insects, centipedes and carrion (4).
Adult males are territorial and will earn and defend a territory, measuring up to 20 metres across, through direct combat (2). Facing another male, the iguana will arch its back and swell its body in an attempt to look larger, and then aggressively butt heads, sometimes drawing blood (2). During the mating season, successful males may mate with up to seven females, each female laying her eggs within the territory of the male (2). Females dig burrows in the soil, into which they lay a clutch of around 2 to 25 eggs (6). Three to four months later, the eggs hatch and the young take up to a week to dig themselves out of the nest (2) (6). Due to predation by hawks, owls, snakes and herons, less than 10 percent of hatchlings survive (2), but should they survive, land iguanas can live for more than 50 years (6).
A remarkable relationship exists between the Santa Fe land iguana and the birds of Santa Fe Island; whilst standing high on all four legs, ground finches and mockingbirds move over, around, and under the iguana, plucking ticks and mites from its scaly skin (2) (4).