The cuckoo for many people continues to be, as it was for Wordsworth, a ‘wandering voice’ as opposed to a bird to be recognised when seen. ‘The first cuckoo of the year continues to be heard in Blankshire’ is the usual type of the evidence accepted like a news item by some local as well as national newspapers-and the dates often become more incredible every year.
To the conscientious recorder, therefore, the sight of the first cuckoo is all-important. This general power of interest upon the voice alone-common to both countryman and town-dweller-is all the more puzzling because excited sexual and territorial chases, often involving several birds, are typical occurrences right after arrival.
The latter is generally from the beginning of April onwards. In most types of summer migrants (out of the box obvious in the easily identified cock blackcap) the male arrives well in front of the female, to be able to claim and begin a breeding-territory. This is unnecessary in the case of the cuckoo, as it is the female that is the chooser and holder of territory; thus not infrequently the first birds of both sexes might be seen on the 24 hour. Since the far-carrying voice of the male is exactly what usually alerts the observer, it’s less often possible to come across a bubbling female as the first cuckoo of the year-but when by accident this does occur, it’s a peculiarly satisfying experience.
When perched the cuckoo gives an impact of precarious balance, as though the feet, with two toes in-front and two behind, weren’t so efficient in ensuring a company grip as with the arrangement present with true perching birds; this apparent instability becomes much more noticeable when the entire body wobbles at the tail-wag which accompanies each ‘coo-coo’ emitted.
The cuckoo’s unique distinction among British birds is being our only brood-parasite, using other species both for the incubation of their eggs and the rearing of their offspring. The listing of species used as foster-parents is extensive, however in each appropriate kind of country there appears to be a favourite dupe-meadow pipit on mountain and moorland; dunnock in woodland, gardens and hedgerows; reed warbler in watery sites; and pied wagtail in man-made surroundings.
The most fascinating facet of the cuckoo’s migratory habits is the proven fact that the old birds, which in fact had arrived from Africa in spring, depart on the return journey usually before the end of July, in a date when a lot of their offspring continue to be fed in the foster-parent’s nest. The young of the year might not depart until the middle of September; they have to therefore make their first visit to Africa by purely instinctive navigational powers, without the advantage of experienced adults.