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Puzzles of the Heart

11 Jun 2020
Heart Puzzles

This investigation began after being astounded by an unseen insect in the depths of a savanna night in Namibia’s Khaudum National Park. Being in a rooftop tent is a bit like sleeping in a bush. And it was so quiet I could hear my heart.

I became aware of an insect going zik, zik, zik nearby and realised the ziks were exactly on my heartbeat. I couldn’t believe it! Then I noticed something even more alarming. Heartbeats are not regular, but speed up slightly as you breath in. The insect was timing its beats to that rhythm as well.
I listened to this curious synchrony for a while, then my heart gave an arythmic hop – which is quite normal – and the insect did the same. At that point it became surreal. This must have lasted for around10 minutes until the insect flew away.

I warehoused the memory, aware that in its telling I’d be thought nuts or high on something. A bit of digging some time later made me revisit the incident. Last year two sensory biophysics, Erica Morley and Gregory Sutton, published a paper showing that flowers give off electrical signals to attract bees, telling them when they have pollon.

‘It’s a very small electrical field, which is why we're quite astounded that bees can actually detect it,’ they wrote ‘Two flowers of the same species will have a similar electric field, whereas two flowers of a different species will have a different field.’

But it’s not just flowers. A paper in the journal Science listed six species – sharks, certain fish, electric rays, a hornet and the platypus – which generate or sense faint electrical impulses to hunt or simply find what’s around them.

Now here’s the rub.  Electrocardiograms tell us that our hearts produce an electrical impulse on each beat. An insect sitting in a bush only metres away from me could surely sense mine.

Which leads me to two questions. Are those irritating insects zikking at night seeking mates with electrically congruent impulses? And on that savanna night was I being checked out as a possible mate? I’ll never know. But this stuff’s a fruitful line of inquiry for entomologists.

About the Author:


Dr Don Pinnock is an investigative journalist and photographer who, some time back, realised he knew little about the natural world. So he set out to discover it. This took him to five continents – including Antarctica – and resulted in five books on natural history and hundreds of articles. The Last Elephants, published this year with Colin Bell, is his 18th book.

His other books include:

Gang Town, which won the City Press Tafelberg Non-Fiction award,
Writing Left, a biography of the journalist Ruth First.
Voices of liberation
The Brotherhoods,
Gangs, Rituals & Rites of passage
Rainmaker, a novel shortlisted for the 2009 European Union Literary Award.
Natural Selections,
African Journeys,
Just add dust,
Loveletters to Africa,
Blue Ice: Travels in Antarctica,
The Woman who Lived in a Tree and Other Perfect Strangers.
Wild as it Gets,
He has degrees in criminology, political science and African history and is a former editor of Getaway travel magazine.

He was one of the primary drafters of the White Paper that became the Child Justice Act, a trustee of the Chrysalis Academy for high-risk youths, a board member of Wilderness Foundation Africa, a member of the Conservation Action Trust and was the facilitator of the Western Cape Government’s gang strategy roadmap.

His day job is as environmental investigative journalist.