The discovery of a Great Spotted Cuckoo at Gramborough Hill in north Norfolk on 23rd July was a cause for much excitement among certain of my birdwatching friends. Although not a really rare bird, with fewer than 40 individuals recorded in England it was of sufficient interest to draw the crowds. Similar in size to the more familiar Common Cuckoo, this vagrant to our shores is arguably a more attractive bird. Individuals of all ages show a general pattern of dark upperparts (spotted with white) and paler underparts, although in juveniles the upperparts are a very dark grey, almost black, while in adult birds they are a soft silvery-grey. Juveniles also show a rusty-brown wing panel which, coupled with the white belly and lemon yellow throat make for a rather smart bird.
The Great Spotted Cuckoo’s breeding range extends from Spain and Portugal east across southern France to Iran and south to South Africa. Southern populations tend to be resident, while those from further north are migratory, with many individuals wintering south of the equator (though a few remain in southern Spain). The pattern of records from Britain is interesting, in that the first overshooting spring migrants can reach us as early as February, with others reaching us from March through to the end of May. This pattern reflects the very early spring migration period exhibited by the northern populations of this species. However, there is also another cluster of records from late July through into the autumn, typically involving young birds (juveniles or first-years) rather than adults.
Like most other cuckoos, the Great Spotted Cuckoo parasitizes the nests of other birds and within the European part of its breeding range it tends to specialise on the Magpie. Adults feed on caterpillars, often favouring large or hairy species and those that are gregarious in habits; the Processionary Moth appears to be a particular favourite. Habitat-wise within Europe, the Great Spotted Cuckoo makes use of scattered Cork Oak and Stone Pine woodland, but it can also be found in almond and olive groves.
This is only the seventh record of the species in Norfolk, the last being a spring bird found at Waxham in March 1999. The first was a bird shot on the denes between Yarmouth and Caister in 1896 and this individual is now on display at the City of Birmingham Museum. One of the other Norfolk birds is also on display, this time at Castle Museum in Norwich, and involves an individual found dead in the North Dunes at Winterton in August 1958. The species appears to be increasing its breeding range so it seems likely that Norfolk will host more of these rather attractive birds in the future.