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 .
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 .
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 .
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 .
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 .
although they are mainly an eastern north american species , there have been confirmed reports of them in british columbia , washington and california .
the species is also a rare vagrant to western europe and greenland .
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 .
invasive gypsy moths may also serve as an important food source for black-billed cuckoos .
most birds cannot consume gypsy 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 .
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 .
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 .
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 1013 days .
the young black-billed cuckoos , as well as others cuckoos in the genus coccyzus , leave the nest 79 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 .
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 .
black-billed cuckoos are known to lay their eggs in the nests of other birds .
they can lay eggs in the nests of other black-billed cuckoos , called conspecific parasitism , or in the nests of other songbirds , 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 .
many cuckoos are obligate brood parasites , meaning they only lay eggs in other birds' nests and never take care of their own young .
birds that do this , such as the common cuckoo or the brown-headed cowbird , lay relatively small eggs because their expected hosts are usually smaller birds .
cuckoos in the genus coccyzus , lay relatively large eggs even though they still parasitize smaller birds .
yellow warblers are the smallest birds recorded caring for black-billed cuckoo eggs .
in experiments , these wood warblers were found to accept the cuckoo eggs 63% of the time even though their own eggs are only a quarter of the size .
even with the size difference , the warbler parent is often still able to raise the cuckoo as long as it can provide the chick with sufficient nutrition and incubation .
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 .
