The greater roadrunner is monogamous, forming long-term pair bonds. Greater roadrunner couples defend a territory of about 700 to 800 m in size. The male is more territorial, calling out to warn competitors, and does not hesitate to physically push the intruders out of his territory. Some couples defend the same territory all year long
This bird walks around rapidly, running down prey. It feeds mainly on small animals including insects, spiders (including black widows), tarantulas, centipedes, scorpions, mice, small birds, including hummingbirds, and especially lizards and small snakes. Venomous serpents, including small rattlesnakes, are readily consumed.
Because of the greater roadrunner's diurnal nature and arid habitat, it has various biological and behavioral adaptations, known as thermoregulation, to reduce dehydration and overheating. During the hot season, it is active mostly from sunrise to mid-morning, and late afternoon to evening. It rests in the shade during the hottest part of the day.
The greater roadrunner is found in the Aridoamerica ecoregion, within the southwestern United States and northern Mexico. It can be seen regularly in the US states of California, Arizona, New Mexico, Texas, Nevada, Utah, Colorado, and Oklahoma, and less frequently in Kansas, Louisiana, Arkansas, and Missouri.
The greater roadrunner can be found from 60 m (200 ft) below sea level to 2,300 m (7,500 ft) (rarely up to 3,000 m (9,800 ft)). It occupies arid and semiarid scrubland, with scattered vegetation (typically less than 50% cover) with a height of less than 2–3 m (6.6–9.8 ft).
The Greater Roadrunner can maintain a speed of 30 km per hour over long distances. While running, it places its head and its tail parallel to the ground, and uses its tail as a rudder to help change its direction. It prefers to run in open areas, such as roads, packed trails and dry riverbeds rather than dense vegetation.