Breeding pairs: 16,000
Family: Cuckoos
The adult male cuckoo has slate-grey upperparts. Its tail is dark brown with white spots, white tips, and black bars. The underparts are pale grey with heavy dark grey and black bars, while the breast is a pale slate-grey. The undertail feathers are black with white spots and edges.
The head is grey, the slightly curved bill is yellow with a black tip, the eyes are yellow-brown to orange with a yellow eye-ring, and the legs and feet are orange-yellow.
The adult female cuckoo is similar in appearance, but the upper breast may be rufous instead of grey.
The juvenile cuckoo has pale brown upperparts with heavy black bars and white-tipped feathers. Its tail has black bars, and the underparts are white with fine dark grey bars. The eyes are dark brown with a yellow eye-ring, and it has a distinctive white patch on its nape.
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Cuckoos are brood parasites, meaning they lay their eggs in the nests of other birds, most commonly dunnocks and robins, leaving the host birds to incubate and raise their young. Female cuckoos can lay up to 50 eggs in a season, though many are rejected by the host. Approximately one-third of the eggs are rejected if laid before the host has laid any of its own, and about three-quarters are rejected if one of the host’s eggs is replaced.
To increase the chances of acceptance, female cuckoos lay eggs that mimic the markings of the host bird’s eggs. These eggs are incubated for 11 to 12 days.
When the cuckoo chicks hatch, they instinctively push the host’s eggs and nestlings out of the nest, ensuring they are the sole recipients of food brought by the unsuspecting surrogate parents.
Young cuckoos fledge after 17 to 21 days and reach sexual maturity at two years old.
Cuckoos eat insects; mainly hairy caterpillars, beetles and ants but also dragonflies, crickets and mayflies.
Adult cuckoos arrive in the UK in late March and April and leave for Africa in July with juveniles leaving a month later.
They can be seen throughout the UK but are mostly found in southern and central England.
Britain's Birds
RSPB Handbook Of British Birds
Collins Bird Guide
The common cuckoo is the only member of the family that calls cuckoo-cuckoo-cuckoo.
One Response
Is the male cuckoo much smaller than the female? I have watched two female cuckoos (I think) but they are accompanied by a smaller bird that seems to be chasing them.watched them on a telegraph pole and the smaller one was in the middle of them while they were cooing away and again tonight the same thing was happening