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 )
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:
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
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 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
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 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 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
There are no known adverse effects of black-billed cuckoos on humans.
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
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
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)
More often heard than seen, the Black-billed Cuckoo (11-12 inches) is most easily separated from the similar Yellow-billed Cuckoo (Coccyzus americanus) by its solid brown wings, plain under-tail pattern, and all-black bill. Other field marks include a long tail, thin body, and black legs. Male and female Black-billed Cuckoos are similar at all seasons. The Black-billed Cuckoo breeds across much of the northeastern U.S. and southern Canada. All Black-billed Cuckoos spend the winter in South America, although this species’ winter range is poorly known due to its highly secretive nature. Some Black-billed Cuckoos have been found in the western U.S. during the fall migration, likely resulting from navigational errors. Black-billed Cuckoos breed in forests with plentiful undergrowth and clearings, particularly those near water. On migration, this species may be found in habitat similar to that inhabited during the summer months. Wintering Black-billed Cuckoos inhabit humid tropical forest. The diet of this species is composed primarily of large insects, including grasshoppers, cicadas, and caterpillars. Like many cuckoos, the Black-billed Cuckoo spends much of its time hidden in thick vegetation, where it is not easily seen. Lucky birdwatchers may observe this species slinking through the branches of tall trees while foraging for insect prey. Black-billed Cuckoos are primarily active during the day, but like many migratory birds, this species migrates at night.
More often heard than seen, the Black-billed Cuckoo (11-12 inches) is most easily separated from the similar Yellow-billed Cuckoo (Coccyzus americanus) by its solid brown wings, plain under-tail pattern, and all-black bill. Other field marks include a long tail, thin body, and black legs. Male and female Black-billed Cuckoos are similar at all seasons. The Black-billed Cuckoo breeds across much of the northeastern U.S. and southern Canada. All Black-billed Cuckoos spend the winter in South America, although this species’ winter range is poorly known due to its highly secretive nature. Some Black-billed Cuckoos have been found in the western U.S. during the fall migration, likely resulting from navigational errors. Black-billed Cuckoos breed in forests with plentiful undergrowth and clearings, particularly those near water. On migration, this species may be found in habitat similar to that inhabited during the summer months. Wintering Black-billed Cuckoos inhabit humid tropical forest. The diet of this species is composed primarily of large insects, including grasshoppers, cicadas, and caterpillars. Like many cuckoos, the Black-billed Cuckoo spends much of its time hidden in thick vegetation, where it is not easily seen. Lucky birdwatchers may observe this species slinking through the branches of tall trees while foraging for insect prey. Black-billed Cuckoos are primarily active during the day, but like many migratory birds, this species migrates at night.
The black-billed cuckoo (Coccyzus erythropthalmus) is a New World species in the Cuculidae (cuckoo) family. The scientific name is from Ancient Greek. The genus name, kokkuzo, means to call like a common cuckoo, and erythropthalmus is from eruthros, "red" and ophthalmos, "eye".[2]
It is very similar and overlaps in range with the closely related yellow-billed cuckoo. A distinguishing characteristic of family Cuculidae is laying eggs in the nests of other birds. Although many cuckoos are obligate brood parasites, C. erythropthalmus often incubate their own chicks.[3]
Adults have a long, graduated brown tail and a black, slightly downcurved bill. The head and upper parts are brown and the underparts are white. The feet are zygodactylous. Juveniles are drabber and may contain some rufous coloration on the wing. The adults have a narrow, red orbital ring while the juveniles' is yellow.[7] Black-billed cuckoo chicks have white, sparsely-distributed, sheath-like down that contrasts heavily with their black skin. They also have complex, creamy-colored structures on their mouth and tongue, which may appear like warts or some type of parasitic infection however they are normal for the species.[8]
C. erythropthalmus may be found in a variety of habitats. They are most commonly found around the edges of mature deciduous or mixed forests and much less frequently in coniferous forests. They can also be found in much younger growth forests with a lot of shrubs and thickets. Wetlands with a lot of alder and willow are another prime location to see them. Lastly, they can also inhabit more open areas such as abandoned farmland, golf courses and residential parks. Whatever the habitat may be, they are usually quite well hidden and tend to stick to the edges of these habitats. The chosen habitat must also have a water source nearby such as a lake, river, marsh or pond. On their wintering grounds in South America, they can inhabit tropical rainforests, deciduous or semiopen woodlands as well as scrub forests.[6]
When breeding, the species is distributed in wooded areas across much of the United States, east of the Rockies. Their range just barely extends into North Carolina, Arkansas, Oklahoma and Tennessee. They are not present to the south of those states when breeding. They can also be found in southern regions of Alberta, Saskatchewan, Manitoba, Ontario and Quebec. They're also present in the maritime provinces of Prince Edward Island, eastern New Brunswick and western Nova Scotia. When migrating in spring and fall, they can also be seen in southern United States as well as all of Central America. They migrate to northwestern South America in the fall, where they will spend the winter.[9] Although they are mainly an eastern North American species, there have been confirmed reports of them in British Columbia, Washington and California.[10] The species is also a rare vagrant to western Europe and Greenland.[11][12][13]
These birds forage in shrubs or trees. They mainly eat insects, especially tent caterpillars, but also some snails, eggs of other birds and berries. It is known to beat caterpillars against a branch before consuming them to remove some of the indigestible hairs. Remaining hairs accumulate in the stomach until the bird sheds the stomach lining and disgorges a pellet in a manner similar to owls.[14][15]
Invasive spongy moths may also serve as an important food source for black-billed cuckoos. Most birds cannot consume spongy moth caterpillars because of their hair-like setae however, cuckoos can consume them because of their ability to shed their abdominal lining. During outbreak years of these insects, the abundance of black-billed cuckoos increased on Breeding Bird Survey (BBS) routes. This increase is not due to higher reproductive rate because then the black-billed cuckoo populations would only increase the next year. The abundance is higher because the cuckoos flock towards the outbreak areas. This is supported by the fact that cuckoo abundance is actually lower than average in the areas surrounding the outbreaks, suggesting a large influx of the birds towards outbreaks. They are able to find these areas due to post-migratory nomadic behavior. Once reaching their breeding ground, they search vast expanses of forest for the most suitable breeding area, in this case, where there is an abundance of food. Similar patterns have also been observed during outbreaks of tent caterpillars, fall webworms and cicadas.[16][17]
When they are a couple days old, the chicks can make a buzzing sound that resembles an insect and a few days later, they can make a low barking call when disturbed. The call of this species is 2-5 sets of "coo" notes that are high-pitched, rapid and repetitive. There is a slight pause between each set. The phonetics are often written "coo-coo-coo-coo, coo-coo-coo-coo, coo-coo-coo-coo, ...". Adults usually call during the day when breeding however they begin calling at night, in the middle of summer.[6][9]
Prior to copulation, the male lands on a branch near the female with an insect in its beak. The female will then flick her tail up and down intermittently for about 15 minutes while the male sits there motionless. The male then mounts the female, with the insect still in its mouth, and the two copulate. The male then either eats the food item or gives it to the female for her to eat.[6]
Females usually lay 2-3 blue-green eggs, sometimes 4 or 5, which may take on a marbled appearance after a couple days of incubation. Adults incubate the eggs for 10–13 days. The young black-billed cuckoos, as well as others cuckoos in the genus Coccyzus, leave the nest 7–9 days after hatching, which is quite young when compared to other birds. The young are not able to fly right away however they can still move quite large distances by jumping between tree branches. During this period, they are more vulnerable to predators because they cannot fly away as the adults could. Due to this vulnerability, the juveniles can slowly assume an erect posture to conceal themselves. They stretch their neck out and point their bill upwards, while keeping their eyes open and remaining motionless. If the threat starts to back off, the cuckoo will relax its pose.[18]
Outbreaks of tent caterpillars can have a positive effect on black-billed cuckoo populations. During these outbreaks, the adults begin laying eggs earlier in the season. They can also produce larger clutches and may even increase their parasitic activities.[19]
Black-billed cuckoos generally build their own nests, weaving loose structures of twigs, dried leaves and pine needles about 2 metres (6.6 ft) above the ground.[20][21] However, in years with an abundance of food sources (such as outbreaks of periodical cicadas), the species may engage in brood parasitism.[22] They can lay eggs in the nests of other black-billed cuckoos, called conspecific parasitism, or in the nests of other birds, known as interspecific parasitism. The females will usually parasitize nests in the afternoon because the nests are often unguarded at this time. This cuckoo species is thought to have a laying interval of about a day so if two eggs show up in a nest on the same day, you can rightfully assume that one is a parasitic egg.[3]
The black-billed cuckoo was originally placed in genus Cuculus. This genus comprises Old World cuckoos that are all obligate brood parasites. Upon further genetic testing, it was placed into genus Coccyzus that comprises nine species of New World cuckoos. The black-billed and yellow-billed cuckoos are the only two that migrate into North America while the other seven are permanent residents of either Central or South America. Even though these two cuckoos overlap in range, they are not sister taxa. This suggests that the two species invaded North America separately. Although family Cuculidae is monophyletic, the genus Coccyzus was found to be polyphyletic.[23][24]
Although the black-billed cuckoo is classified as Least Concern (LN) on the IUCN red list, its population is still on the decline. It faces many of the same challenges as many other North American songbirds. Pesticides are having a large effect on them because the chemicals are depleting their food resources. Other threats include the loss of habitat, especially in their wintering tropical habitats, as well as urbanization. As with other migratory birds, they frequently encounter large buildings on their migratory routes which they may collide with, resulting in death.[9]
The black-billed cuckoo (Coccyzus erythropthalmus) is a New World species in the Cuculidae (cuckoo) family. The scientific name is from Ancient Greek. The genus name, kokkuzo, means to call like a common cuckoo, and erythropthalmus is from eruthros, "red" and ophthalmos, "eye".
It is very similar and overlaps in range with the closely related yellow-billed cuckoo. A distinguishing characteristic of family Cuculidae is laying eggs in the nests of other birds. Although many cuckoos are obligate brood parasites, C. erythropthalmus often incubate their own chicks.
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