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.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
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.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
There are no known adverse effects of black-billed cuckoos on humans.
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.
Positive Impacts: controls pest population
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.
Ecosystem Impact: parasite
Species Used as Host:
Commensal/Parasitic Species:
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.
Animal Foods: fish; eggs; insects; mollusks; terrestrial worms
Plant Foods: seeds, grains, and nuts; fruit
Primary Diet: carnivore (Eats non-insect arthropods, Vermivore); herbivore (Frugivore , Granivore ); omnivore
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.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
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.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: forest ; scrub forest
Wetlands: marsh
Other Habitat Features: urban ; suburban ; agricultural ; riparian
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.
Range lifespan
Status: wild: 5 (high) years.
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.
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.
Range mass: 40 to 65 g.
Range length: 28 to 31 cm.
Range wingspan: 34 to 40 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: female larger
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.
Known Predators:
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.
Mating System: monogamous
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).
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.
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.
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.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
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.
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)
