ALL CREATURES GREAT AND SMALL
Patrick Barkham celebrates the long-standing residents that make up Britain’s rich fauna This month CUCKOOS
Patrick Barkham celebrates Britain’s rich fauna. This month: cuckoos
A FOOTLOOSE WANDERER FROM TRURO TO TIMBUKTU, settling nowhere for more than a couple of months. A promiscuous parent, who disdains to raise young and dupes smaller creatures into maternal duties. A noisy caller whose voice is a unique song of spring. The cuckoo may seem astonishingly immoral but that is to anthropomorphise an innocent animal. The real miracle is that this slim grey bird exists at all. The lifestyle it has chosen is peculiar and almost ridiculously precarious.
Our relationship with the cuckoo begins at this time of year with its “cuck-coo” call. One note is a noise but two notes are a tune, and this sound “is the most remarkable noise in the natural world”, according to Michael Mccarthy, author of Say Goodbye to the Cuckoo. It’s a perfect musical interval: a descending minor third. “Because it’s a minor third, it has a mournful note,” he says. “Occasionally a cuckoo sings in a major third, which is less mournful. And cuckoo clocks chime in a major third, which is why they are so annoying.” It may be mournful, but the call, like the bird, is also strangely difficult to locate. Wordsworth captured its elusiveness:
O blithe New-comer! I have heard, I hear thee and rejoice. O Cuckoo! shall I call thee Bird, Or but a wandering Voice?
Unsurprisingly, there is something witchy about the cuckoo, which is rarely seen and easily confused with a bird of prey. Its call has prophetic qualities in folklore – a French saying suggests that if you hear a cuckoo and have money in your pocket, then you will be rich all year; many other European traditions suggest that the bird can foretell your longevity or when you will marry.
In Britain, we only hear its wandering voice when it arrives to breed. During a spring dawn, or dusk, the male’s mournful, sonorous call can be heard a mile beyond. A female will pair with more than one but the species is really famed for what comes next. Eighteenth-century naturalist Gilbert White admired the female’s craft in locating nests belonging to suitable species in which to deposit its eggs. But he denigrated its “monstrous outrage on maternal affection”.
AN ABSENT PARENT
This bird’s parasitic parenting was only fully revealed by cuckoo obsessive Edgar Chance, who named his daughter Cardamine after the scientific name of the cuckoo flower, and amassed a collection of 25,000 birds’ eggs, including 25 from a single female cuckoo during one breeding season. In 1922, Chance dispatched children to watch nests on a Worcestershire common to deduce which the cuckoo would visit. Hiding in a fake stack of hay, he successfully filmed The Cuckoo’s Secret, a ground-breaking documentary. Perhaps Chance empathised with the cuckoo’s outlaw status: his egg collection eventually led to his expulsion from the British Ornithologists’ Union.
His film revealed the bird’s cunning approach – placing single, colour-matched eggs into nests while dropping or devouring her fosterer’s own eggs. We recoil from pictures of diminutive reed warblers or meadow pipits feeding baby cuckoos that are monstrously bigger than they are – a Pathé News film of Chance’s work was entitled The Home Wrecker. The cuckoo lends its name to other domestic deceptions: for instance, to be a cuckold, a man whose wife is adulterous, is seen as a humiliation.
There are, however, still more cuckoo secrets to discover. Until a few years ago, a traditional rhyme held that…
In April, come he will, In May, he sings all day, In June, he changes his tune In July, he prepares to fly In August, away he must
Satellites proved this wrong, though. In 2011, scientists led by Dr Chris Hewson from the British Trust for Ornithology (BTO)
put GPS tags on the birds. Before the tagging, there was just one clue about where the cuckoo flew: a youngster ringed in a pied wagtail’s nest in 1928 was later recovered in Cameroon (well, the ring was; the bird was taken for the pot). But satellites revealed a more complex picture. Cuckoos aren’t heard in July because most are halfway to Algeria by then. While we originally thought they travelled only as far as West Africa, the truth is that they journey a great deal further. One (named Chris Packham) spent winters in the swamp forest of the Congo Basin, but on his third winter abruptly relocated to Angola, a further 1,000km away. Satellite tags revealed that it rarely stayed in one location for more than two months. The BTO’S research revealed that cuckoos mostly return to their British breeding grounds but choose two distinctive migratory paths: birds from southern England leave later and take a shorter, western route via Spain. Birds from northern Britain take a longer, eastern route, leaving ten days earlier to complete it. Unexpectedly, Hewson has found survival rates on the eastern route to be significantly higher; birds on the westerly route are struggling.
A PICKY EATER
Besides its call, parenting and globe-trotting, the cuckoo’s diet is its final oddity. It devours hairy caterpillars – so hairy that the gizzards of dissected cuckoos can look furry. Mostly these are large moths, such as Emperor moths. Scientific data reveals that, south of Lancaster and York, moth populations fell by 40 per cent over 40 years but numbers held up in northern Britain. Michael Mccarthy believes it is no coincidence that northern cuckoos are surviving, while the cuckoo has virtually vanished from south-east England, where agricultural intensification has decimated moth populations. However, while these different research projects have unveiled elements of the bird’s hidden life, Hewson believes we still have a lot to learn about these enigmatic creatures: “We have convincing evidence that what we know is not the whole story.” It is certainly mournful that the cuckoo’s call is no longer so widely heard, but there is something heartening about the fact that there is still such mystery surrounding this remarkable bird.
A reed warbler (Acrocephalus scirpaceus) feeding a 12-day-old European cuckoo chick in its nest in the East Anglian Fens
ABOVE Hairy caterpillars are a favourite meal for cuckoos TOP A European cuckoo (Cuculus canorus) in flight over North Uist in the Outer Hebrides