[order] Cuculiformes | [family] Cuculidae | [latin] Coccyzus erythrophthalmus | [UK] Black-billed Cuckoo | [FR] Coulicou à bec noir | [DE] Schwarzschnabelkuckuck | [ES] Cuclillo Piquinegro | [IT] Cuculo occhirossi | [NL] Zwartsnavelkoekoek

Zwartsnavelkoekoek determination

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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.

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.

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.

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.

This species has a large range, with an estimated global Extent of Occurrence of 4,900,000 km². It has a large global population estimated to be 1,100,000 individuals (Rich et al. 2003). Global population trends have not been quantified, but populations appear to be stable (del Hoyo et al. 1997) so the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

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.
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.
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. The incubation period is 10 to 11 days and both parents are present during incubation, replacing each other at different intervals throughout the day.
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.

Migratory, moving at night through Mexico and Central America as late as Dec. Spring migration records at TV towers, where nocturnal migrants are killed, in Florida, Apr - May; autumn migrants late Aug to late Oct. Winters in W South America from Venezuela, Colombia, Ecuador and N Peru to Bolivia, from lowlands to 2800 m near Quito, Ecuador; accidental in N Argentina, Paraguay and Trinidad. Also transatlantic vagrant in autumn to W Europe.