Loud Sing Cuckoo

Yesterday afternoon, walking with my son (conversing by megaphone from a safe social distance, of course) on Ashtead common, I had the rare pleasure of hearing a cuckoo. I haven't heard one in these parts for years, but there it was, loud and clear and unmistakable, calling about ten times, then falling silent. We didn't see the elusive bird ('No bird but an invisible thing, a voice, a mystery,' according to Wordsworth) and the call was some way off, but it was a wonderful thing to hear.
Traditionally May is the month when the cuckoo sings. As the summer advances, it loses its voice:

When summer from the forest starts
Its melody with silence lies,
And, like a bird from foreign parts,
It cannot sing for all it tries.
'Cuck cuck' it cries and mocking boys
Crie 'Cuck' and then it stutters more
Till quick forgot its own sweet voice
It seems to know itself no more.

Those are the closing lines of John Clare's The Cuckoo, a poem that begins 'The cuckoo, like a hawk in flight, With narrow pointed wings'. This resemblance to a hawk – specifically the sparrowhawk – led many to believe that cuckoos turn into sparrowhawks for the winter, then back into cuckoos for the summer. Since then, of course, science has exposed the real life of the cuckoo, and it is quite amazing enough. The bird shows extreme ingenuity in getting its eggs into another bird's nest and ensuring that the unwitting bird rears the gigantic chick that hatches from that egg. The cuckoo lurks nearby, watching the target nest and awaiting its opportunity, then nips in, tips any other eggs out of the nest, lays its own egg (marked to resemble the host bird's eggs) and flies off – all in about ten seconds. What is more, as it leaves it makes a call that sounds like a sparrowhawk, thereby warning the host bird to stay away. The wonders of Nature, eh?

It's an old chestnut, but Delius's On Hearing the First Cuckoo in Spring is still a very fine tone poem. This quintessentially English piece had its first performance in Leipzig (along with Summer Night on the River), and its second theme is taken from a Norwegian folk song...