Today, had I not been otherwise engaged, I would have gone to Dartmoor to search for cuckoos. I might have gone to Emsworthy Mire or to Gidleigh Common by Scorhill Farm or even to Throwleigh Common near to Great Ensworthy. Last year I listened to and saw cuckoos at these places, but sadly this year I will have to imagine them but I know they will be there!
To get my mind running I am assisted by some poetry – no less a person than William Wordsworth, describing his joy at hearing a cuckoo return to the Lake District.
O blithe New-comer! I have heard,
I hear thee and rejoice.
O Cuckoo! shall I call thee Bird,
Or but a wandering Voice?
O blessed Bird!
the earth we pace
Again appears to be
An unsubstantial, faery place;
That is fit home for Thee!
And John Clare, a contemporary of Wordsworth writing about cuckoos in his Northamptonshire village of Helpston.
The cuckoo, like a hawk in flight,
With narrow pointed wings
Whews o’er our heads – soon out of sight
And as she flies she sings:
And darting down the hedgerow side
She scares the little bird
Who leaves the nest it cannot hide
While plaintive notes are heard.
The cuckoo however, is a marmite bird, despite the millions of years of its evolutionary journey where it has re-invented itself as an exploiter of other birds, its habits repulse others. A paradox bird – the herald of spring and new life on one hand and the cruel deceiver taking life on the other.
Ted Hughes captures the latter view.
The cuckoo’s the crookedest, wickedest bird,
His song has two notes but only one word.
He says to the linnet: Your eggs look so ill!
Now I am the doctor, and here is my pill.”
Within that pill, the cuckoo-child
Crouches hidden, wicked and wild.
He bursts his shell, and with weightlifter’s legs
He flings from the nest the linnet’s eggs.
Then bawls to the linnet: “Look at me, Mam!
How quickly I’ve grown, and how hungry I am!”
She thinks he is hers, she is silly with joy.
She wears herself bare for the horrible boy.
Till one day he burps with a pitiless laugh,
“I’ve had enough of this awful caf.
And away he whirls, to Cuckooland,
And leaves her to weep with a worm in her hand.
What is so curious about this poem is the species of bird that Hughes has chosen to become the victim of the cuckoo – a linnet. Very occasionally cuckoos will lay an egg in a linnet’s nest but it is a fatal mistake for the cuckoo as well as the linnet. Linnets are seed eating birds whilst cuckoos need a diet of insects; the cuckoo chick hatches, ejects the linnet’s clutch of eggs and then starves to death. Hughes was a good naturalist and a keen observer of nature, maybe I have missed something, maybe it’s just creative licence.
Part of the inherited evolutionary genius of the cuckoo is its ability to mimic the egg patterns of its host in both colour and markings. What makes this all the more extraordinary is that cuckoos parasitise a range of host birds. Wordsworth’s cuckoos’ would lay eggs in meadow pipit nests whilst Clare’s would have chosen the dunnock. In areas where there are extensive wetlands cuckoos utilise the nests of reed warblers. These three species of passerine birds have very different coloured and patterned eggs and as a result cuckoos have evolved into host-specific races.
My own interest in cuckoos developed when I worked at Wicken Fen in Cambridgeshire and met the legendary Professor Nick Davies who used the reserve as his laboratory to study cuckoos and their interactions with reed warblers. Nick is a brilliant academic, a lovely, lovely man and very generous with his time. Ecologists will know of him as well through his textbook ‘An Introduction to Behavioural Ecology’.
In his book ‘Cuckoos – cheating by nature’ he wrote
Without a moment’s hesitation, the warbler bows deep into the enormous mouth to deliver the food ….
I am amazed by what I have just seen …
Why, when confronted by a young cuckoo, so different in appearance and far too big to be one of their own chicks, are the warblers apparently so stupid?
I am amazed by the cuckoo chick too. How does it stimulate the little warblers to bring enough food?
And why do adult cuckoos abandon their young and entrust them to another species?
In his book Nick goes on to answer these questions, based on his own research at Wicken Fen along with his numerous PhD students and other academics around the world. It is the most amazing story – if you love nature, are puzzled by evolution and curious about animal behaviour you will love this very readable book – it will make lockdown time fly by.
And now …. I have been to ‘Cuckooland’ without leaving my house.