Coccyzus americanusyellow-billed cuckoo

Geographic Range

Yellow-billed cuckoos are found in the Nearctic and Neotropical regions. They breed throughout eastern North America, in southeast Canada, northern Mexico and the Greater Antilles. They winter primarily in South America (Peru, Bolivia and northern Argentina). (Hughes, 1999)


Yellow-billed cuckoos prefer open woodlands with clearings and a dense shrub layer. They are often found in woodlands near streams, rivers or lakes. In North America, their preferred habitats include abandoned farmland, old fruit orchards, successional shrubland and dense thickets. In winter, yellow-billed cuckoos can be found in tropical habitats with similar structure, such as scrub forest and mangroves. (Hughes, 1999)

Physical Description

Yellow-billed cuckoos are medium birds (26 to 30 cm long; 55 to 65 g) with long tails. They have uniform grayish-brown plumage on their head and back, and dull white underparts. Their tails are long with two rows of four to six large white circles on the underside. The bill of yellow-billed cuckoos is short to medium in length and curved downward with a black upper mandible and a yellow or orange lower mandible. Yellow-billed cuckoos have zygodactylous feet, meaning that of the four toes, the middle two point forward and the outer two point backward. (Parker)

Female yellow-billed cuckoos are slightly larger than males. Juveniles are similar in appearance to adults, but have a less distinct undertail pattern, and have cinnamon brown wing coverts.

There are two recognized subspecies of Coccyzus americanus; Coccyzus americanus americanus (the eastern version) and its western counterpart, Coccyzus americanus occidentalis. These two subspecies are differentiated by tail, wing and bill length. (Hughes, 1999)

  • Sexual Dimorphism
  • female larger
  • Range mass
    55 to 65 g
    1.94 to 2.29 oz
  • Range length
    26 to 30 cm
    10.24 to 11.81 in


Yellow-billed cuckoos are probably monogamous, though their breeding system has not been well studied. Breeding pairs form in May or June, and pairs may visit prospective nest sites together before choosing a location. Males may attempt to procure or keep a mate by offering sticks and other nest materials to their mate as well as feeding them (Eaton, Erlich et al). (Hughes, 1999)

Yellow-billed cuckoos begin breeding in mid- to late-May. Most populations breed once per year, though some eastern populations may raise two broods in one breeding season. The male and female build the nest, which is made of twigs, lined with roots and dried leaves, and rimmed with pine needles. The female may begin laying eggs before nest construction is complete. She lays 1 to 5 (usually 2 or 3) light blue eggs, and begins incubating after the first egg is laid. Incubation is done by both parents, and lasts 9 to 11 days.

Yellow-billed cuckoo chicks are altricial at hatching, and are brooded often by the parents for the first week or so. Both parents feed the chicks, which begin to leave the nest 7 to 9 days after hatching. They begin to fly about 21 days after hatching. Soon thereafter they leave the nest for good. The male will usually take care of the first fledgling, and the female will care for the rest (Ehrlich et al.). There is little information available on when yellow-billed cuckoo chicks become independent from their parents. Most yellow-billed cuckoos begin breeding at age 1.

Some yellow-billed cuckoos may parasitize other birds by laying eggs in the nest of other parents. They may lay eggs in the nest of other yellow-billed cuckoos, or in the nests of other bird species, including black-billed cuckoos, American robins, gray catbirds and wood thrushes. (Hughes, 1999)

  • Breeding interval
    Most populations breed once per year, though some eastern populations may lay two broods in one breeding season.
  • Breeding season
    Yellow-billed cuckoos begin breeding in mid- to late-May
  • Range eggs per season
    1 to 5
  • Average eggs per season
    2 to 3
  • Average eggs per season
  • Range time to hatching
    9 to 11 days
  • Range fledging age
    7 to 9 days
  • Average age at sexual or reproductive maturity (female)
    1 minutes
  • Average age at sexual or reproductive maturity (male)
    1 minutes

Male and female yellow-billed cuckoos incubate eggs, brood and feed chicks and protect the nest from predators. They also keep the nest clean by removing the fecal sacs of the chicks. After chicks have left the nest, the parents continue to feed them until they are able to care for themselves. The length of this period is unknown. (Hughes, 1999)

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


There is little information available about the lifespan and survivorship of yellow-billed cuckoos. The oldest re-captured banded yellow-billed cuckoos were 4 years old at re-capture. (Hughes, 1999)


Yellow-billed cuckoos are solitary or live in pairs during the breeding season. They may be territorial, but this aspect of their behavior is not well understood. Yellow-billed cuckoos are fully migratory. They migrate at night in small groups or large flocks. Outside of migration, yellow-billed cuckoos are generally diurnal. (Hughes, 1999)

Communication and Perception

Yellow-billed cuckoos primarily use vocalizations to communicate. They are generally silent birds during the winter and migration, but vocalize regularly during the early breeding season before the chicks fledge. These birds are able to make at least 6 vocal sounds, which are used for a wide variety of social situations. Few physical displays have been noted in this species. (Hughes, 1999)

Food Habits

Yellow-billed cuckoos primarily eat large insects including caterpillars (order Lepidoptera), katydids, cicadas (family Cicadidae), grasshoppers and crickets (order Orthoptera). They also occasionally eat bird eggs, snails, small vertebrates such as frogs (Order Anura) and lizards (suborder Sauria) and some fruits and seeds. Parents feed their chicks regurgitated insects (Ehrlich et al.).

  • Animal Foods
  • amphibians
  • reptiles
  • eggs
  • insects
  • mollusks
  • Plant Foods
  • seeds, grains, and nuts
  • fruit


Adult yellow-billed cuckoos are killed by raptors, including Aplomado falcons (Falco femoralis) and red-shouldered hawks (Buteo lineatus). Remains of adults have also been found in the stomach of a tiger shark (Galeocerdo cuvier). Nestlings and eggs are vulnerable to predation by snakes such as the black racer (Coluber constrictor), small mammals such as eastern chipmunks (Tamias striatus), and birds such as blue jays (Cyanocitta cristata) and common grackles (Quiscalus quiscula).

When threatened by a predator, yellow-billed cuckoos often hide themselves among vegetation and remain motionless. If a nest is threatened, parents will either attack the predator or try to lure the predator away from the nest by flying away and performing a distracting display and vocalizations. (Hughes, 1999)

Ecosystem Roles

Yellow-billed cuckoos affect the populations of the species they prey on. They are also host to internal and external parasites.

Yellow-billed cuckoos are also nest parasites, and may affect the reproductive success of species that they parasitize. Some yellow-billed cuckoos parasitize other birds by laying eggs in their nests. They may lay eggs in the nest of other yellow-billed cuckoos, or in the nests of other bird species, including black-billed cuckoos, American robins, gray catbirds and wood thrushes. If the parasitized parents raise the foreign young, their own chicks may be less likely to survive or flourish. (Hughes, 1999)

Species Used as Host

Economic Importance for Humans: Positive

Yellow-billed cuckoos may help to control populations of pest insects.

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

There are no known adverse affects of yellow-billed cuckoos on humans.

Conservation Status

Yellow-billed cuckoos are protected under the U.S. Migratory Bird Act. They are considered threatened or endangered in several states, and are a candidate for protection under the U.S. Endangered Species Act. Yellow-billed cuckoos are common in parts of their range, but populations have been declining in recent years throughout much of the range. This decline is most likely due to habitat loss and fragmentation. Other threats to cuckoo populations include poisoning from pesticides and other environmental contaminants and collision with towers and tall buildings during their nocturnal migration. (Hughes, 1999)


Kari Kirschbaum (editor), Animal Diversity Web.

Megan Hilt (author), University of Michigan-Ann Arbor.



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.


Referring to an animal that lives in trees; tree-climbing.

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 eats mainly insects or spiders.


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).


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.


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


"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.


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

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


lives alone


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.


uses sight to communicate


Eaton, Stephan. 1997. Notes on the Reproductive Behavior of the Yellow-billed Cuckoo. The Wilson Bulletin. Vol. 19, No. 1:154-5. March.

Ehrlich, Paul R., David S. Dobkins and Darryl Wheve. 1988. The Birder's Handbook. Simon and Schuster, Inc., New York. p.286.

Fleischer, Robert C., Michael T. Murphy and Lawrence E. Hunt. 1985. Clutch Size Increase and Intraspecific brood parasitism. The Wilson Bulletin. Vol. 97, No.1:125-7. March.

Franzreb, Kathleen E. and Stephan A. Laymon. 1993. A Reassessment of the Taxonomic Status of the Yellow-billed Cuckoo. Western Birds. Vol. 24: 17-28.

Lasley, Greg W. and Chuck Sexton. 1985. South Texas Region. American Birds. Vol 39: 933-36.

Laymon, Stephan A. and Mary D. Halterman. 1987. Can the Western Subspecies of the Yellow-billed Cuckoo be Saved from Extinction. Western Birds. Vol. 18, No.1: 19-25.

Parker, Sybil P., ed. 1982. Synopsis and Classification of Living Organisms. Vol. 2: 988-989. McGraw-Hill Inc., New York. pp.988-989.

Allaby, Michael, ed. 1985. The Oxford Dictionary of Natural History. Oxford University Press, Oxford. pp.148.

Wolfe, Donald H. 1994 Yellow-billed Cuckoo Hatched in Mourning Dove Nest. Bulletin of the Oklahoma Ornithological Society. Vol XXVII, No. 4: 29-30. December.

Hughes, J. 1999. Yellow-billed cuckoo (Coccyzus americanus). Pp. 1-28 in A Poole, F Gill, eds. The Birds of North America, Vol. 418. Philadelphia, PA: The Birds of North America.