Aristotle should have known better. He was, after all, the father of all modern scientific method, based on direct observation and strict logic.
He even rubbished his mentor, Plato, who had in turn been taught by Socrates.
Aristotle believed the folklore that nightjars sucked the milk of goats, at night, when the shepherds were not looking.
Direct observation! Oh yes, the birds had been seen fluttering at the teats in the dark. It was only too obvious what they were up to; they had such wide, gaping mouths designed to drain every drop of milk from a goat.
Slings, arrows and muskets were aimed at the nightjar, called Goatsucker, Devil-bird, and Puckeridge during the next two millennia as a result of Aristotle’s record.
Generations of people became really terrified of them. They inhabited the nether world,
they were black spirits that thrived in that frightening and haunted place where night brought danger.
They even sucked the goats dry. So 18th-century taxonomists were happy to translate goat into Latin and give the nightjar the official name of Caprimulgus for ever more.
But then in 1870 a bird watcher looked a little more closely at what the nightjar was doing. “It was a warm, moonlit night,” Charles Waterton related in
his book Wanderings. “Mosquitoes and flies were swarming around the bellies of cattle, sheep and goats.
“Fluttering around them and then landing beneath was a nightjar which was feasting on these insects.
“Especially open to attack were the udders, and the nightjar was able to reach up and catch flies off the teats of sheep and goats from a standing position.
“All the animals stood quite still as they realised they were being deloused.
“How quiet they stood, how sensible they seemed of his good offices for they neither struck him, nor hit him with their tails, nor trod on him, nor tried to drive him away as an uncivil intruder.
“Were you to dissect him and inspect his stomach you would find no milk there, only the flies which had been annoying the herd.”
In fact one bird killed accidentally in recent times did have its crop investigated and inside were discovered 1,000 insects of 50 species.
Another contained 500 mosquitoes, while a third had eaten 2,175 flying ants.
So if you see nightjars this summer at Iping, or any of the other Sussex haunts such as Ambersham, Angmering, Ashdown, Heyshott, Wiggonholt, or Burpham, you will know that this Fissirostral, or big-mouthed bird, is only doing you good by getting rid of the mossies and midges, but it took 2,000 years to put the record straight.
They remain mysterious birds nevertheless, with their black cross, twilit shapes, wing clapping, and ventriloqual calls that rattle almost everlastingly in the darkness.
You may even be lucky enough to see one as in this painting by Philip Rickman, but nightjars are crepuscular and shun the daylight.