A semi-arboreal species (1), the Michoacan dwarf spiny-tailed iguana generally rests during the night in a hollow cavity in tree cacti. The iguana will block the entrance to the cavity by arching its large, muscular spiny tail. As the iguana grows, it will take shelter in larger cavities (1) (3).
In general, most species of spiny-tailed iguanas will venture out from their retreats during the day, when the outside temperature reaches a comfortable level. The iguanas then bask in a sunny area until their optimum body temperature is reached. Reptiles are unable to maintain their own body temperature and therefore rely on sources of heat from the environment, such as the sun, to increase the temperature of the body and provide them with enough energy to sustain their daily activities (6).
Throughout the day, spiny-tailed iguana species will usually forage, bask, rest and display, before returning to their retreats as the sun starts to set. Displays typically involve a male spiny-tailed iguana patrolling its territory by standing high on its legs, flattening its body, and bobbing its head with its mouth open to intimidate other males (2).
Reproduction in spiny-tailed iguanas begins with the male chasing the female. Following capture, the male uses its front legs to pin down the female, and uses its mouth to hold the female by the back of the neck while attempting to copulate. Eight to ten weeks after mating, the female digs a nest in the ground in which to lay the eggs. The eggs take around 90 days to hatch, depending on the temperature. Upon hatching, the young iguanas immediately dig their way out of the underground nest (2).