|Range of G. californianus|
The greater roadrunner (Geococcyx californianus) is a long-legged bird in the cuckoo family, Cuculidae, from the Aridoamerica region in the Southwestern United States and Mexico. The Latin name means "Californian earth-cuckoo". Along with the lesser roadrunner, it is one of two species in the roadrunner genus Geococcyx. This roadrunner is also known as the chaparral cock, ground cuckoo, and snake killer.
The roadrunner is about 52-62 cm (20-24 in) long, has a 43-61 cm (17-24 in) wingspan and weighs 221-538 g (7.8-19.0 oz). It stands around 25-30 cm (9.8-11.8 in) tall and is the largest cuckoo of the Americas. Roadrunners have four toes on each zygodactyl foot; two face forward, and two face backward. The toes are brown in color and have pale gold spots. The upper body is mostly brown with black streaks and sometimes pink spots. The neck and upper breast are white or pale brown with dark brown streaks, and the belly is white. A crest of brown feathers sticks up on the head, and a bare patch of orange and blue skin lies behind each eye; the blue is replaced by white in adult males (except the blue adjacent to the eye), and the orange (to the rear) is often hidden by feathers.
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). Cases where roadrunners have run as fast as 42 km/h (26 mph) have been reported. This is the fastest running speed clocked for a flying bird, but not nearly as fast as the 70 km/h (40 mph) of the flightless and much larger ostrich.
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, as well as the Mexican states of Baja California, Baja California Sur, Sonora, Sinaloa, Chihuahua, Durango, Jalisco, Coahuila, Zacatecas, Aguascalientes, Guanajuato, Michoacán, Querétaro, México, Puebla, Nuevo León, Tamaulipas, and San Luis Potosí. The species is not migratory.
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 Roadunner 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.
The roadrunner less often engages in flight. It hovers from a perch, such as a tree or a human construction. More rarely, it flies short distances of 4 or 5 meters, between potential roosts.
This bird walks around rapidly, running down prey. It feeds mainly on small animals including insects, spiders (including black widows), tarantulas, scorpions, mice, small birds, and especially lizards and small snakes. Venomous serpents, including small rattlesnakes, are readily consumed. It kills prey by holding the victim in its bill and slamming it repeatedly against the ground.
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.Body water may be retained via liquid reabsorption, by the mucous membranes in the cloaca, rectum and caecum. The roadrunner's nasal glands eliminate excess body salts.
The greater roadrunner reduces excess heat by the formation of water vapor, released by breathing or through the skin. It sometimes pants in heavy heat, to accelerate this action. At night, it reduces its energy expenditure by more than 30 percent, lowering its body temperature from 40 to 34 degrees Celsius. In the morning, it accelerates heat recovery by sunbathing. In winter, it takes refuge in dense vegetation or among rocks to shelter from cold winds.
The roadrunner frequently sunbathes for warmth. It turns perpendicular to the ground with its back turned towards the sun. Wings apart, the roadrunner ruffles the black feathers on its back and head, exposing its black skin, allowing both skin and feathers to absorb the heat of the sun's rays. Early in the morning, it can stay in this posture for two or three hours. In winter, when the temperatures are around 20 °C, roadrunners may warm themselves in the sun several times during the day, more than half an hour at a time.
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.
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. Greater roadrunners lay three to six eggs, which hatch in 20 days. The chicks fledge in another 18 days. Pairs may occasionally rear a second brood when there is an abundance of food in rainy summers.
The vocalizations of the greater roadrunner have seven distinct variants. The 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. Females give off a number of up to twenty-two short, low-frequency shrills, resembling coyote squeals, which can be heard 300 meters away. Both male and female roadrunners emit a series of five or six chatters accompanied by groaning, loud enough to be heard 200 meters away. This sound is the roadrunner's most common vocalization during the incubation period and the rearing of chicks.
Greater roadrunner fossils dating from the Holocene and Pleistocene have been found in California,New Mexico, Texas,Arizona, and the Mexican state of Nuevo León. The oldest known fossil comes from a cave in New Mexico, estimated at an age of 33,500 years. In the La Brea Tar Pits, fragments from 25 greater roadrunner fossils have been found. Several other fossils are also known from Santa Barbara and Kern counties, as well as Northern Mexico.
Prehistoric remains indicate that up until 8,000 years ago, the greater roadrunner was found in sparse forests rather than scrubby deserts; only later did it adapt to arid environments. Due to this, along with human transformation of the landscape, it has recently started to move northeast of its normal distribution. Sparse forests can be found in these parts, in an environment similar to the prehistoric North American Southwest.
Some Pueblo Native American tribes, including the Hopi, believed the roadrunner provided protection against evil spirits. In Mexico, some said it brought babies, as the white stork was said to in Europe. Some Anglo frontier people believed roadrunners led lost people to trails.
It is also the mascot of numerous high schools and colleges in the United States, including the University of Texas at San Antonio.
University of California publications in zoology
Hoese, William; Anticona, Steve; Olmos, Erik; Parent, John; Rutti, Donald; Velasco, Beth (March 2013). "Greater Roadrunner (Geococcyx californianus) Kills Juvenile Desert Cottontail (Sylvilagus audubonii)". Southwestern Naturalist. 58 (1): 124-126. doi:10.1894/0038-4909-58.1.124.