The sound of a cuckoo calling on the edge of woodland or along hedgerows is truly the herald of springtime. So recognisable is this call that there can be few of us who are unfamiliar with it. As such, the call of the cuckoo, along with the bird itself, has become embedded within our very culture. It is at the heart of perhaps the oldest verse written in (old) English "Sumer is icumen in, Lhude sing cuccu!" (the manuscript is in the British library). The cuckoo has informed some of our most famous art works and cultural icons: from the once ubiquitous Cuckoo Clock to Delius’s exquisite tone poem ‘On Hearing the First Cuckoo in Spring’ and John Wyndham’s sinister sci-fi novel ‘The Midwich Cuckoos’.
The cuckoo’s cultural significance is somewhat surprising, given that of all our regular migratory birds it is the briefest of visitors. It arrives in late March or early April having wintered in Africa and has left our shores by the end of July or early August. Moreover, the appearance of the bird is not particularly remarkable, and you would be forgiven for not noticing it should you happen see it.
The cuckoo is about the size of a collared dove. It is blue-grey in colour and has a white underside with dark barring. It has the general look of a male sparrowhawk, with which it can be confused. However, a closer inspection will reveal the clear differences; a slim, short beak that has a downward curve, short legs and at rest often holds its wings in a drooped downward position.
The cuckoo is what is known as a ‘parasitic breeder’ - the only bird we have in the UK to be so. I don’t particularly like this pejorative term because it is so reductive and undermines the quite remarkable ingenuity that this bird displays in its nesting habits.
The female will spend quite some time reconnoitring an area, seeking out suitable nests for her eggs. She will carefully observe the nest construction and egg laying, and will assess the moment it’s right for her to go to the nest remove one of the hosts’ eggs and lay her own. She will leave, carrying the removed egg in her beak which she will often eat. She will repeat this about every 48 hours in different nests. Up to 25 eggs may be laid although it’s more likely to be around nine.
Fifty different host species have been recorded in the UK. Some research has suggested that a particular bird will repeatedly select the same species. Moreover, it is believed that her female off-spring will go on to select the nests of the breed of their adoptive parents, in which to lay their eggs. The most common birds selected as foster parents are Reed Warbler, Meadow Pipit, Dunnock, Pied Wagtail and Robin.
The cuckoo egg will hatch in around 12 days, a similar - or sooner -time to that of the host species eggs. The new hatchling is altricial - naked, blind, and completely dependent on its foster parents. However it does display a remarkable instinctive behaviour, ensuring undivided attention; within hours of hatching, utilising a hollow in its back, it works hard to push each and every other egg out from the nest leaving just itself to consume every item of offered food.
Last summer, on Salisbury Plain, I was lucky enough to see two Cuckoos together in flight. It was a wonderful spectacle, in which one of the birds seemed to be in pursuit of the other. At first glance I thought I was witnessing a Sparrowhawk giving chase to a Cuckoo but a closer look revealed that both of the birds were indeed Cuckoos. What was even more remarkable was that one of the birds was calling out its usual cuckoo call, and that that call was delivered with its customary slow clarity. In no way did the Cuckoo’s fast, frantic flight match its relaxed call. I guess I would have expected the bird’s ‘cuckooing’ to have increased along with its pace. Little wonder, then, that the Cuckoo has become synonymous with dim-wittedness and even madness.
Sadly, the Cuckoo is on the UK ‘red list’. There are three categories in grading birds for conservation concern, comprising green, amber or red; green being of least conservation concern and red being the most concerning. The Cuckoo, then, is of serious conservation concern. It is not entirely clear whether the problem is here in the UK, during it’s migration route or its wintering grounds in Africa.
As an insectivorous feeder, the cuckoo is known for its preference for hairy caterpillars that other birds will avoid. We know that many invertebrate species are in decline. The authoritative UK State of Nature report highlights various declines in a range of species, so it is clear that all is not well. How we use our land; care for our natural resources; grow our food and value wildness are all of concern.
We shouldn’t need reminding that these substantial declines in biodiversity, taking place all around us, are alarming and should be of concern to us humans. We are one of the natural species that inhabit, share and depend on the very same environment where this loss of biodiversity is taking place. We should make actively caring for it a priority; we can even be selfish about it - our own future wellbeing depends on it. And there is nowhere better to start than in our own back gardens and then we can spread out from there.
Incidentally, there is a marvellous study presently being carried out by the BTO (British Trust for Ornithology) in which a number of satellite tagged cuckoos are being tracked. You can read about the project and view the birds progress on maps on the BTO website:
© Michael Groves