A familiar summer visitor, Cuckoos are found across Europe from early April to mid September. Cuckoos frequent a wide variety of habitats, from woods to reedbeds, coastal dunes to moorland.
The Cuckoo’s long tail and pointed wings sometimes lead to confusion with certain birds of prey such as falcons or hawks. The fast flight is also rather raptor-like. However, once its famous call is heard, there is no identification problem.
The Cuckoo has developed a very sneaky way of raising its young. The female will lay her eggs in other birds’ nests, garden species such as the Dunnock and Robin always being favourites, and ‘allow’ the new parent the pleasure of raising a huge youngster, which slowly but surely ‘evicts’ the other eggs and nestlings.
Upon arrival, the male’s far-carrying familiar ‘cuc-coo’ call resounds around the country. Males will also utter a stuttering ‘cuc-cuc-coo’ and, when agitated, a gargling, laughing ‘gug, gug, gug, gug’.
Cuckoos fly in a very direct manner, usually fairly low to the ground, but they are also very capable of gliding some distance. On landing, the wings droop and the tail is raised.
A male Cuckoo shows an entirely silvery-grey head and upper breast. The mantle and most of the wings are very slightly darker and the flight feathers are very dark grey. The rump is the same shade of grey as the head and breast, while the tail is again dark, but with white notches on each tail feather, complete with an obvious white tail tip. The underparts from lower breast to the undertailcoverts are barred black and white. The bill is orange-yellow at the base with a dark tip, and the eye is orange with a thin yellow orbital ring. The legs and feet are orange-yellow.
The distinctive rufous-brown phase of the female Cuckoo is scarcer than the more familiar grey birds, but not so rare as some books would have you believe. The entire upperparts of the bird, except for the primaries, show a rufous ground colour with fine black barring from head to tail. The underside is barred black and white from chin to tail, with a cinnamon wash on the cheeks, breast sides and the underside of the tail. The bare parts are as the male’s. In flight, the colour of the upperparts, coupled with the shape of the bird, presents a very striking sight.
Grey-phase female Cuckoos are identical to the male except for a distinct brownish wash on the breast and browner-looking flight feathers.
Juvenile Cuckoos, once fledged, still take advantage of the surrogate parents’ hospitality. Their plumage appears very scaly above – a dark grey ground colour on the head and back, with white edges to the feathers. The wings are similar, but show more brown flecks. The throat and upper breast are marked with dense black and white bars, which are more widely spaced from the lower breast to the tail.