Cuckoos
- Order: Cuculiformes
- Family: Cuculidae
Only just over 50 of the 140 or so species in the
cuckoo family practice brood parasitism, but it’s these bad apples that have
earned the family its bad reputation.
Brood parasitism involves the cuckoo laying its
egg in the nest of another bird. The owners of the nest bring the cuckoo chick
up as one of their own, even after it has pushed the other chicks out of the
nest.
Cuckoo, any of numerous birds of the family Cuculidae (order
Cuculiformes). The name usually designates some 60 arboreal members of the
subfamilies Cuculinae and Phaenicophaeinae. In western Europe “cuckoo,” without
modifiers, refers to the most common local form, elsewhere
called the common, or European, cuckoo (Cuculus canorus). Many cuckoos
have specialized names, such as ani, coua, coucal, guira, and roadrunner. Members of the subfamily Neomorphinae are called ground cuckoos.
The family
Cuculidae is worldwide, found in temperate and tropical regions but is
most diverse in the Old World tropics. Cuculids
tend to be shy inhabitants of thick vegetation, more often heard than seen.
Many species are named for the sounds they make—e.g., brain-fever bird (a
hawk cuckoo, Cuculus varius), koel (Eudynamys scolopacea), and cuckoo itself, the latter
two names being imitations of the bird’s song.
Cuculids range in
length from about 16 cm (6.5 inches) in the glossy cuckoos (Chrysococcyx and Chalcites) to about
90 cm (36 inches) in the larger ground cuckoos. Most are coloured in drab grays
and browns, but a few have striking patches of rufous (reddish) or white, and
the glossy cuckoos are largely or partially shining emerald green. Some of the tropical cuckoos
have strongly iridescent bluish plumage on
their backs and wings. With the exception of a few strongly migratory species,
most cuckoos are short-winged. All have long (sometimes extremely long),
graduated tails, usually with the individual feathers tipped with white. The
legs vary from medium to rather long (in the terrestrial forms) and the feet
are zygodactyl; i.e., the outer toe is reversed,
pointing backward. The bill is rather stout and somewhat downcurved.
The attribute for which the cuckoos are best
known is the habit of brood
parasitism, found in all of the Cuculinae and three species of
Phaenicophaeinae. It consists of laying the eggs singly in the nests of certain
other bird species to be incubated by the foster parents, who rear the young
cuckoo. Among the 47 species of cuculines, various adaptations enhance the survival of the young cuckoo: egg mimicry, in which the cuckoo egg resembles that of the
host, thus minimizing rejection by the host; removal of one or more host eggs
by the adult cuckoo, reducing both the competition from host nestlings and the
danger of recognition by the host that an egg has been added to the nest; and
nest-mate ejection, in which the young cuckoo heaves from the nest the host’s
eggs and nestlings. Some species of Cuculus resemble
certain bird-eating hawks (Accipiter) in appearance and
mannerisms, apparently frightening the potential host and allowing the cuckoo
to approach the nest unmolested.
The nonparasitic phaenicophaeine cuckoos are
represented in North America by the widespread yellow-billed and black-billed cuckoos (Coccyzus
americanus and C. erythropthalmus) and the mangrove cuckoo (C. minor), which is
restricted in the United States to coastal southern Florida (also found in the West Indies and Mexico to northern South America); they are represented in Central and South America by about
12 other species, some placed in the genera Piaya (squirrel
cuckoos) and Saurothera (lizard
cuckoos). The 13 Old World phaenicophaeine species are divided among nine genera.
The phaenicophaeine cuckoos build flimsy stick
nests in low vegetation. Both parents share in incubation and feeding the young.
