Coccyzus erythropthalmusblack-billed cuckoo

Geographic Range

Black-billed cuckoos are found in the Neartic and Neotropical regions. In the United States they live from the east coast south to Oklahoma, west to Montana and north to Canada. During the non-breeding season, black-billed cuckoos migrate to northern South America, including Venezuela, Columbia and as far south as central Bolivia. These birds also migrate through the southeastern United States and lowland areas of southeastern Mexico in tropical forests, cloud forests, and arid scrub habitats. (American Ornithologists' Union, 1998; Hughes, 2001)


Black-billed cuckoos are found in wooded areas and wetlands. They are also inhabitants of deciduous forests, where they prefer orchards and thickets, and habitats near natural water, such as a river, stream, or lake. Black-billed cuckoos have sometimes been found in urban and suburban settings on golf courses or in parks. (Hughes, 2001)

Physical Description

Black-billed cuckoos weigh from 40 to 65 grams. They are 28 to 31 centimeters in length and have a wingspan of 34 to 40 centimeters. Black-billed cuckoos have slim bodies and possess a long tail. The upper part of the head and body is a grayish-brown, while the entire underside is white. The bill is black and curves downward. Adult black-billed cuckoos have a reddish ring around their eyes. (Andersson, 1995; Hughes, 2001; National Geographic Society, 1983; Robbins, et al., 1966)

Juveniles are similar in appearance except that they have a yellowish or buff-colored eye ring. The white underside of the juveniles may be more cream colored and some parts of the wings may be rusty-brown in appearance. Female black-billed cuckoos are somewhat larger in size than the male. Their close relatives, yellow-billed cuckoos, are similar to black-billed cuckoos in terms of body shape and color. The biggest differences between the two are that yellow-billed cuckoos have a yellow lower mandible and reddish-brown wings. (Andersson, 1995; Hughes, 2001; National Geographic Society, 1983; Robbins, et al., 1966)

  • Sexual Dimorphism
  • female larger
  • Range mass
    40 to 65 g
    1.41 to 2.29 oz
  • Range length
    28 to 31 cm
    11.02 to 12.20 in
  • Range wingspan
    34 to 40 cm
    13.39 to 15.75 in


Male black-billed cuckoos land on a branch near a potential female mate. The male will hold a food item in his mouth. Next, the male will let out a loud "Cucucu" call. If the female is interested she will move to a branch closer to the male. The female will flip her tail up and down while giving a "Mew" call. The female may flick her tail for up to 15 minutes. The male remains quiet and doesn’t move during this time. The male will then hop to the female’s branch and mount the female. Copulation may be performed at uneven times lasting usually 4 to 5 minutes. Afterwards the male will either eat his food item or feed it to the female. These birds are most likely monogamous. They are solitary during the breeding season, but have been observed in pairs during migration. (Hughes, 2001)

Black-billed cuckoos form mated pairs in mid or late May, sometimes not until June. The pair will then gather materials and build a nest. Nests are most commonly made with small twigs that are loosely woven together. The lining of the nest is made up of leaves, pine needles, and empty cocoons. The nest is made in groves of trees and thickets that are well concealed by leaves and tangles of vines. They are placed 1 to 2 meters above the ground. Nests are constructed continuously through incubation. Black-billed cuckoos may also lay their eggs in the nests of other birds, making them brood parasites (see Ecosystem Roles). (Hughes, 2001; Rylander and Rylander, 2002; Spencer, 1943; Wayne, 1911)

Black-billed cuckoos breed as early as May and as late as September, breeding peaks in June and July. The eggs of black-billed cuckoos are elliptical. Egg length is 22.6 to 32.3 mm and width is 18.3 to 23.5 mm. The eggs are greenish-blue and sometimes appear marbled. Black-billed cuckoos generally lay a single egg at 2-day intervals. (Hughes, 2001; Rylander and Rylander, 2002; Spencer, 1943; Wayne, 1911)

It is possible to tell when birds are incubating eggs by observing the lower breast and abdomen, where an incubation patch - or area free of feathers - will develop. The incubation period is 10 to 11 days and both parents are present during incubation, replacing each other at different intervals throughout the day. Hatching occurs in the early morning. The adult may push the shell around the nest. After about five minutes, the nestling will give a low call and leave the shell. The young bird is alert and active within minutes. Hatchlings fledge at about 3 weeks old and begin to search for food around 21 to 24 days old, sometimes accompanied by the adult. (Hughes, 2001; Rylander and Rylander, 2002; Spencer, 1943; Wayne, 1911)

  • Breeding interval
    Breeding occurs once yearly.
  • Breeding season
    Breeding occurs from May through September.
  • Range eggs per season
    2 to 5
  • Range time to hatching
    10 to 11 days
  • Average fledging age
    17 days
  • Range time to independence
    21 to 24 days
  • Average age at sexual or reproductive maturity (female)
    unknown weeks
  • Average age at sexual or reproductive maturity (male)
    unknown weeks

Both parents are responsible for building the nest for their eggs. Both parents participate in incubation and brooding. Adults will also spread their wings and tail out to cover the eggs and protect them from rain. Hatchlings are altricial, but they develop quickly and leave the nest within 17 days. Both parents are responsible for feeding young. Adults will crush the food for their young and thrust the food into their mouths. The adults will also shade the chicks from the sunlight. The young expel wastes into sacs after feeding and adults either eat or remove the sacs. (Hughes, 2001)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • pre-weaning/fledging
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • male
      • female
    • protecting
      • male
      • female


There is little information on the lifespan of black-billed cuckoos. Since 1955, only 26 out of 6,028 banded black-billed cuckoos have been recovered. Four of these were four years old and one was at least five years old. (de Magalhaes, et al., 2005; Hughes, 2001)

  • Range lifespan
    Status: wild
    5 (high) years


Black-billed cuckoos rarely hop from branch to branch. When they do, they move quietly and with a controlled, three beat gait. Black-billed cuckoos fly gracefully. Black-billed cuckoos spread their wings to dry after it rains. They are most likely territorial, but there is no direct evidence of this reported in the literature. Black-billed cuckoos can be aggressive towards others for food and will dive and chase away others from the nest. During the breeding season, black-billed cuckoos are solitary or seen with their mating partner. During migration they occur in mixed flocks with other species. Black-billed cuckoos migrate only at night by using the patterns of the stars. (Hughes, 2001)

Home Range

There is not a lot of information on home range or territory size. Only one banded black-billed cuckoo was recovered and it was within 2 kilometers of its banding location. (Hughes, 2001)

Communication and Perception

Black-billed cuckoos mainly use acoustics to communicate with other cuckoos. They can make around six different sounds, each for various social conditions. At the age of 1 to 3 days, the young produce a call similar to the buzzing of an insect followed by a low, barking call at 6 to 7 days old. The most frequently heard call is a fast and rhythmic series of "cu-cu-cu-cu". This call comes in a set of 2 to 5, all at the same pitch. The Croak call sometimes follows the "cu-cu-cu." The Croak call is 5 short, lower pitched notes "Krak-ki-ka-kruk-kruk". The Croak call can also be heard alone. A low, sad call consists of notes in sets of 2 to 4, with no pause in between the "coo-oo-oo". This call may be used when a predator is near. During courtship, females use a "mew" call to excite the males. This call is also heard when feeding the nestlings. When they use the alarm call, black-billed cuckoos let out a quick fragment of notes that sound like "cuck-a-ruck". During winter migration they are usually quiet. Calls are normally heard during the day and at night in midsummer. (Hughes, 2001)

Food Habits

Black-billed cuckoos are omnivores feeding mainly on large insects, including especially caterpillars, cicadas, katydids, butterflies, grasshoppers, and crickets. They occasionally eat eggs of other birds and rarely eat aquatic larvae and fish. In the summer, they occasionally feed on fruits and seeds. Other food items include moth larvae, fall webworm, beetles, stink bugs, snails, and dragonflies. (Hughes, 2001; Rylander and Rylander, 2002)

  • Animal Foods
  • fish
  • eggs
  • insects
  • mollusks
  • terrestrial worms
  • Plant Foods
  • seeds, grains, and nuts
  • fruit


Predators of adult black-billed cuckoos include hawks and falcons. Nestlings are taken by common grackles (Quiscalus quiscula) and arboreal snakes and arboreal mammals, such as raccoons (Procyon lotor)s. Black-billed cuckoos are usually taken during migration when birds are tired upon arrival or unfamiliar with the terrain. Black-billed cuckoos are seen and caught easily while crossing open areas.

When a predator is near a nest, an adult cuckoo will align its head, neck, and body in a straight line. It will then "Mew" or give a "Cucucu" call. If the predator is not frightened away, the adult cuckoo will fan out its tail, spread its wings, and let out a "cuck-a-ruck" call. The young assume a perpendicular position with their bill pointed up when a predator is nearby. They remain motionless with widely opened eyes until the predator leaves. (Hughes, 2001)

Ecosystem Roles

Black-billed cuckoos are considered brood parasites. They will sometimes lay their eggs in the nests of other black-billed cuckoos. They have also been reported to lay their eggs in the nests of the yellow-billed cuckoos (Coccyzus americanus), chipping sparrows (Spizella passerina), American robins (Turdus migratorius), gray catbirds (Dumetella carolinensis), and wood thrushes (Hylocichla mustelina). There is little information on the effects of this parasitism on the host. Some studies show that black-billed cuckoo nestlings will eject or crowd out the nestlings of the host. Other brood parasites, including yellow-billed cuckoos (Coccyzus americanus) and brown-headed cowbirds (Molothrus ater), have been known to lay their eggs in the nests of black-billed cuckoos.

The only parasitic organism discovered in black-billed cuckoos is a nasal mite, Cytodites therae. However, more studies of this bird are necessary. (Hughes, 2001; Pence, 1973)

Species Used as Host
Commensal/Parasitic Species

Economic Importance for Humans: Positive

Black-billed cuckoos help control the population of pest insects through predation. Studies show that following an outbreak of gypsy moths (Lymantria dispar) the density of black-billed cuckoos increases. These birds disappear several years after the outbreak is under control. (Gale, et al., 2001; Hughes, 2001)

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

There are no known adverse effects of black-billed cuckoos on humans.

Conservation Status

Black-billed cuckoos are protected under the United States Migratory Bird Act. They have a declining population that is based on their global abundance, their breeding and winter distribution, and the threats on breeding and wintering grounds. There are 16 states where black-billed cuckoo populations might be in decline: Iowa, Minnesota, Illinois, Indian, Michigan, Ohio, Wisconsin, North Dakota, South Dakota, Massachusetts, Maine, Connecticut, New Hampshire, New Jersey, Rhode Island, and New York. (Hughes, 2001)


Tanya Dewey (editor), Animal Diversity Web.

Whitney King (author), Radford University, Karen Powers (editor, instructor), Radford 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.

World Map


living in the southern part of the New World. In other words, Central and South America.

World Map


uses sound to communicate


living in landscapes dominated by human agriculture.


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.

bilateral symmetry

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.


an animal that mainly eats meat


uses smells or other chemicals to communicate

  1. active during the day, 2. lasting for one day.

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.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


an animal that mainly eats fruit


an animal that mainly eats seeds


An animal that eats mainly plants or parts of plants.


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).


marshes are wetland areas often dominated by grasses and reeds.


makes seasonal movements between breeding and wintering grounds


Having one mate at a time.


having the capacity to move from one place to another.

native range

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.


an organism that obtains nutrients from other organisms in a harmful way that doesn't cause immediate death


Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).


specialized for leaping or bounding locomotion; jumps or hops.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


lives alone


living in residential areas on the outskirts of large cities or towns.


uses touch to communicate


that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).


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


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


living in cities and large towns, landscapes dominated by human structures and activity.


uses sight to communicate


American Ornithologists' Union, 1998. Check-list of North American Birds. Washington, DC: American Ornithologists' Union.

Andersson, M. 1995. Evolution of reversed sex roles, sexual size, dimorphism, and mating system in coucals. Biological Journal of the Linnean Society, 54: 173-181.

Gale, G., J. DeCecco, M. Marshall, W. McClain, R. Cooper. 2001. EFFECTS OF GYPSY MOTH DEFOLIATION ON FOREST BIRDS: AN ASSESSMENT USING BREEDING BIRD CENSUS DATA. Journal of Field Ornithology, 72, 2: 291-304.

Hughes, J. 2001. Black-billed cuckoo : Coccyzus erythropthalmus. Philadelphia, PA: The Birds of North America, Inc..

National Geographic Society, 1983. Field Guide to the Birds of North America. Washington, DC: National Geographic Society.

Pence, D. 1973. the nasal mites of birds from Louisiana. VIII. Additional records and description of a new species (Acarina: Dermanyssidae, Ereynetidae, Epidermoptidae, and Cytoditidae). Journal of Parasitology, 59/5: 874-880.

Robbins, C., B. Bruun, H. Zim. 1966. Birds of North America. New York: Western Publishing Company, Inc..

Rylander, K., M. Rylander. 2002. The Behavior of Texas Birds. Austin, TX: University of Texas Press.

Spencer, O. 1943. Nesting Habits of the Black-Billed Cuckoo. The Wilson Bulletin, 55, 1: 11-22.

Wayne, A. 1911. The Black-Billed Cuckoo (Coccyzus erythrophthalmus) Breeding on the Coast of South Carolina. The Auk, 28, 4: 485-486.

de Magalhaes, J., J. Costa, O. Toussaint. 2005. "HAGR: the Human Ageing Genomic Resources" (On-line). Accessed December 12, 2008 at