In comparison with the mockingbirds occupying the other islands, the San Cristobal mockingbird is somewhat shy (3). Much of its time is spent foraging through leaf litter for arthropods such as grasshoppers and crickets. Fruits and berries are also taken from low vegetation, and on occasion it can be seen darting amongst the marine iguanas, picking off their ticks (2) (5).
Unlike the other mockingbird species, the San Cristobal mockingbird is not known to breed cooperatively (2) (3) (5). Instead the relatively large, three to five hectare territories are normally occupied by just a single pair, sometimes accompanied by another adult. Breeding takes place from January to April, with each breeding pair building a bulky twig nest, high up in the crotch of a tree, out of reach of introduced predators (3) (5). Incubation of the two to five eggs is left to the female, but both parents share feeding duties (5).