i took this a couple of summers ago, on one of my first outings with my Canon 40D and sigma 150-500mm.
The common european cuckoo is a dove-sized bird with blue grey upper parts, head and chest with dark barred white under parts. With their sleek body, long tail and pointed wings they are not unlike kestrels or sparrowhawks. Sexes are similar and the young are brown. They are summer visitors and well-known brood parasites, the females laying their eggs in the nests of other birds, especially meadow pipits, dunnocks and reed warblers. Their recent population decline makes this a Red List species.