Greater roadrunners are primarily a species of the southwestern United States, but their full range includes other areas as well. They occur in California, Arizona, Nevada, Utah, Colorado, Texas, New Mexico, Kansas, Oklahoma, Louisiana, and Arkansas. Their range continues into southern Mexico, where their closest relative the lesser roadrunner (Geococcyx velox) becomes the dominant species. (Baughman, 2003; Stokes and Stokes, 1996; Youth, 1997)
This species prefers arid deserts and other regions with a mix of scattered brush for cover and open grassy areas for foraging. For breeding, they require coastal sage scrub or chaparral habitat. In the outer limits of their range they may be found in grasslands and at the edges of woodlands. (Crooks, et al., 2001; Soule, et al., 1988; Kaufman, 1996)
The head, neck, back, and wings of greater roadrunners are dark brown-black and heavily streaked with white, while the breast is mostly white. The eyes are bright yellow and there is a postocular streak of bare blue and red skin. A particularly notable feature is the crest of black feathers, which is raised or lowered at will. Overall, the body has a streamlined appearance, with a long tail that may be carried at an upward angle. The legs and beak are blue. The feet are zygodactylous, with two toes pointed forward and two toes pointed backward. The sexes are similar in appearance. Immature greater roadrunners lack the colorful postocular streaks and are more bronze in color.
Greater roadrunners are medium-sized birds, weighing 227 to 341 g. An adult’s length is between 50 and 62 cm and the height is between 25 and 30 cm. Greater roadrunners have a wingspan of 43 to 61 cm. ("Raptor Free Flight Species Information", 2003; Baughman, 2003; Bull, 1978; Stokes and Stokes, 1996)
Courtship behavior involves the male’s foot pursuit of the female, with frequent rests. Food is an important component of the mating ritual. The male will tempt the female with a morsel such as a lizard or snake dangling from its beak. If the female accepts the offered food, the pair will probably mate. In another display, the male wags his tail in front of the female while bowing and making a whirring or cooing sound; he then jumps into the air and onto his mate. Greater roadrunner pairs may mate for life. (Baughman, 2003; Kaufman, 1996; Youth, 1997)
The breeding and nesting seasons vary geographically. In regions where there is one rainy season they nest only in the spring. Where there are two rainy seasons and thus more food resources, they will nest again in August and September. Brood size ranges from 2 to 8 eggs, which are white or pale yellow. Incubation lasts about 20 days and begins after the first few eggs are laid. Hatching is therefore asynchronous. Young are altricial and their development is quite rapid; they can run and catch their own prey at 3 weeks. Sexual maturity is reached at 2 to 3 years of age. (Bull, 1978; Gough, et al., 1998; Kaufman, 1996)
Both parents help build the nest; while the male collects the materials, the female does most of the construction. The nest site is almost always a few feet above the ground in a bush, cactus, or low tree. It is made with sticks, grass, feathers, and sometimes snakeskin or cow manure. Both parents incubate the eggs and feed the chicks once they hatch. Although the young leave the nest within 18 to 21 days, the parents continue to feed them for up to 30 to 40 days.
Greater roadrunners occasionally engage in brood parasitism. For example, roadrunner eggs have been observed in the nests of the common raven and the northern mockingbird. (Aragon, et al., 1999; Kaufman, 1996; Stokes and Stokes, 1996; Youth, 1997)
The lifespan of G. californianus is 7 to 8 years. Factors that may limit their survival include predation by hawks, house cats, skunks, coyotes, or raccoons. Further, since greater roadrunners are a nonmigratory species, they may succumb to icy weather in a particularly cold year. ("Raptor Free Flight Species Information", 2003; Youth, 1997)
Greater roadrunners are non-migratory and pairs defend their territories year-round. These birds can run up to 17 miles an hour. In fact, they prefer to walk or run and will fly only when absolutely necessary. Even then, they can only remain airborne for a few seconds. The long tail is used for steering, braking, and balancing. They are also known for their curiosity; they won't hesitate to approach humans. Greater roadrunners have also been observed "sunbathing." In the morning and on cooler days, they position their scapular feathers so the black skin on the dorsal apteria can absorb the sunlight and warm the body. Conversely, they must also cope with the scorching heat of the southwest. One way they do so is by reducing their activity by 50% in the heat of midday. Other desert adaptations include entering hypothermia at night to conserve energy, water conservation when water is scarce, and a salt-secreting nasal gland. (Kaufman, 1996; Ohmart and Lasiewski, 1971)
Greater roadrunners have a wide range of vocalizations. The song of G. californianus is a series of six slow, low coos in descending pitch. During the mating season males will also attract females with a whirring call. The alarm call is a clackety noise produced by clicking the mandibles together in a sharp and rapid manner. The chicks give a buzzing begging call. (Baughman, 2003; Bent, 1964)
The diet of G. californianus is omnivorous and varied, a good strategy for survival in the typically harsh environments of the southwest. They eat large insects, scorpions, tarantulas, centipedes, lizards, snakes, and mice. They have even been known to eat rattlesnakes, although this is rare. Greater roadrunners are potential predators of quail, adult sparrows, hummingbirds such as Anna's hummingbird, and the golden-cheeked warbler. Feeding on netted birds has also been reported. They feed on prickly pear cactus where available. When hunting they walk rapidly, scanning for prey, and then dash forward to make the catch. They may also jump into the air to catch passing insects. To kill small creatures such as rodents, greater roadrunners smash the prey's body and head against a rock and then swallow it whole. Often part of the animal is left hanging out of the mouth while it is being digested. (Baughman, 2003; Kaufman, 1996; Komar and Thurber, 2003; Lobas, 2001; Youth, 1997)
Hawks, house cats, skunks, coyotes, and raccoons prey upon greater roadrunners. Coyotes also eat their eggs. This species relies largely on its swiftness to outrun predators. It also uses patches of brush for hiding, and it places its nest above ground to deter predation on the eggs. (Kaufman, 1996; Youth, 1997)
Geococcyx californianus plays both predator and prey roles. It eats, and therefore potentially reduces the populations of, many small vertebrates such as lizards, mice, and other birds. It also consumes insects and other invertebrates. Greater roadrunners provide food for predators such as coyotes, hawks, skunks, and raccoons. (Youth, 1997)
Greater roadrunners help eliminate pests such as mice and various insects. Humans are frequently captivated by the odd behavior of the species. (Youth, 1997)
There are no known adverse affects of Geococcyx californianus on humans.
Habitat loss and urban sprawl are the major threats to greater roadrunners. The construction of roads causes fragmentation of habitat as well as mortality from cars. Greater roadrunners are also illegally shot in response to predation on quail. Further, agricultural pesticides can adversely affect the species if bioaccumulated through their prey.
Research shows that Geococcyx californianus has little chance of persisting in coastal southern California, where sage scrub areas occur only in highly populated areas. Development has reduced this potential habitat to patches too small for greater roadrunners’ large territorial requirement. (Bolger, et al., 1997; Crooks, et al., 2001)
Recently, a right femur from the greater roadrunner’s ancestor, Geococcyx californianus conklingi, was discovered in southeastern Arizona. This subspecies is larger than the present-day form of the greater roadrunner, Geococcyx californianus californianus. Modern roadrunner fossils have been found in California, New Mexico, and Chihuahua, Mexico. (Carpenter and Mead, 2001)
Allison Poor (editor), University of Michigan-Ann Arbor.
Elizabeth Grisham (author), Michigan State University, Pamela Rasmussen (editor, instructor), Michigan State University.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
union of egg and spermatozoan
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
Having one mate at a time.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
scrub forests develop in areas that experience dry seasons.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
uses sight to communicate
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