The Greater roadrunner is a long-legged bird in the cuckoo family from the Southwestern United States and Mexico. This bird is also known as the chaparral cock, ground cuckoo, and snake killer. Although capable of limited flight, it spends most of its time on the ground and can run at speeds up to 32 km/h (20 mph). There were even cases when roadrunners have run as fast as 42 km/h (26 mph). This is the fastest running speed clocked for a flying bird that also helps it to be a very effective predator. It is able to capture not only snakes but also chase fast-running lizards and rodents.
Greater roadrunners are found in the Aridoamerica ecoregion, within the southwestern United States and northern Mexico. They are not migratory and occupy desert, scrubland with scattered vegetation, riparian woodlands, and canyons.
Greater roadrunners live in pairs all year within their territory which they defend from intruders. Because of their greater diurnal nature and arid habitat, these birds have developed various biological and behavioral adaptations; one of them is thermoregulation, which helps to reduce dehydration and overheating. During the hot season, roadrunners are active mostly from sunrise to mid-morning, and late afternoon to evening. They rest in the shade during the hottest part of the day. Every morning they usually sunbathe to warm up after a cold night in the desert. In winter, when the temperatures are around 20 °C, roadrunners may warm themselves in the sun several times during the day and take refuge in dense vegetation or among rocks to shelter from cold winds. When hunting, these birds walk around rapidly, running down prey. They kill prey by holding the victim in their bill and slamming it repeatedly against the ground. Greater roadrunners don't fly well. They hover from a perch, such as a tree or human construction. More rarely, they fly short distances of 4 or 5 meters (13 or 16 ft), between potential roosts. These birds prefer to run especially in open areas, such as roads, packed trails, and dry riverbeds rather than dense vegetation. Greater roadrunners communicate using various vocalizations. Their most frequent call is a slow and descending sequence of about six low, “cooing” noises, emitted by the male and which is heard at 250 m. This call is usually made early in the morning, from a high perch such as a fence post, dead tree or cactus.
Greater roadrunners are carnivores. They feed mainly on small animals including insects, spiders, tarantulas, scorpions, mice, small birds, and especially lizards and small snakes. Venomous snakes, including small rattlesnakes, are readily consumed. In winter they may supplement their diet with some fruits and seeds.
Greater roadrunners are monogamous and form long-term pair bonds. During the breeding season, males are more territorial, calling out to warn competitors, and do not hesitate to physically push the intruders out of their territory. Nest building starts in March in Texas, and probably later further north. Both birds build the nest, with the male collecting the material and the female constructing the nest. The nests are compact platforms of thorny branches lined with grasses, feathers, snakeskin, roots, and other fine material. They are built low in a cactus or a bush. The female lays 3 to 6 eggs, which hatch in 20 days. The chicks are born helpless and with closed eyes. They fledge in another 18 days but usually rely on their parents for food 30 to 40 days more. Pairs may occasionally rear a second brood when there is an abundance of food in rainy summers.
The main threats to Greater roadrunners include habitat loss and urbanization. They also suffer from illegal shooting, collisions with auto vehicles, and from the use of pesticides.
According to the All About Birds resource the total breeding population size of the Greater roadrunner is 1.1 million breeding birds. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.