Maverick Life

The mysterious decline of Eurasia’s Lesser Kestrels in the Karoo

Males have grey heads and chestnut bodies, while the females have dark speckles. (Photo: Chris Marais)

3 Oct 2024

Thousands of Lesser Kestrels fly from Eurasia to the Karoo every year. But by 2024, it seemed clear that something had gone awry.

In the high summer of February 2023, we witnessed one of the Karoo’s greatest natural phenomena just before dusk behind the snack shop at a filling station in Hanover, along the N1 highway.

Three tatty-looking Scotch pines in the backyard were the favourite roosts of hundreds of Lesser Kestrels (Falco naumanni), small raptors that migrate all the way from Eurasia every year to feast on insects between November and March. At sundown during the high summer, they swirled over the town and Trappieskop, a lovely conical hill on the edge of town. There were a few other roost trees, dotted around town.

We were there a fortnight before the majority left the Karoo to fly back to their northern homes. The garage forecourt offered a decent vantage point, but we wanted to get closer to the roosts, away from the vehicles and hustlers. So we headed into the snack shop, which apparently stocks every flavour of NikNaks in South Africa.

Feathered fighter jets

May we get closer to the valkies, we asked politely.

Of course, they said.

We were led to the back of the shop, weaving through refrigerators, stacks of boxes, wooden chairs and tables, to a door. As soon as we stepped through it, a white wave of startled Lesser Kestrels burst out of the trees above us.

Examination of the regurgitated pellets under the trees revealed twinkling bits of chitin from insect wings.

It was load-shedding time, so a generator rumbled nearby. Dogs barked in a nearby garden. Trucks and cars whooshed by on the N1, their drivers oblivious to the aerial acrobatics happening right above them.

People seemed oblivious to the aerial display over the service station, before the birds’ roosting trees were cut down. (Photo: Chris Marais)

Kestrel These compact raptors favour towns close to open plains, where they can hawk for small prey. (Photo: Chris Marais)

Overhead, it was pure magic, these trim little figures crowding the sky in flight, their wings rigid, like Japanese kites.

As the sun sank lower, the light caught the white feathers under their wings, flashing silver. There were great clouds of them in an ever-changing pattern, flying without a sound or a collision. It was like the Battle of Britain in silence, an air show with swarms of feathered fighter jets revelling in flight, testing themselves against the turbulent air.

A few dozen landed in one of the trees, fiercely pulled their feathers straight, adjusted the trim, and surrendered themselves to the sky again.

Finally, we heard the birds calling as they landed. Their roost trees are the only places you’ll hear them make a sound, a kind of peevish chirrup, or kye-kye.

It was the last time we would ever see them in these particular pines.

Here for the goggas

Danie van Heerden, our host at AshTree Guesthouse, told us that very few of his guests knew about the valkies.

“Sometimes, during load-shedding, I’ll offer to take them outside to have a look. They are astonished.”

Kestrels fly off long before sunrise in small groups, heading off for a day in the Karoo plains. You’ll see them perched on fence lines and telephone poles, hawking for moths, locusts, termites, spiders, lizards and the odd mouse. In Europe they are called “windhovers” for the way they hang in the sky, almost motionless above their prey.

They are solemn, dignified raptors, no larger than rock pigeons. Males have chestnut bodies and blue-grey heads, and females are buffy brown with black flecks.

Of course, Hanover is not the only place to see them.

It just so happens that it was for many years their Karoo stronghold, in the middle of the country, right next to the N1. And they had been coming back there every year, as predictable as the tide.

Kestrel The raptors roost tightly together, often numbering thousands, in a single large tree. (Photo: Chris Marais)

Lesser Kestrels never mate or raise their chicks in Africa. They only overwinter here, fattening up on insects before heading back to breed on roofs, cliffs and in trees from Portugal to Kazakhstan, the Balkans to war-torn Ukraine, as far north as Siberia and up to western China.

When they arrive in early summer, their primary wing feathers are worn to a nub, nearly naked after their long flights. They immediately set about moulting them.

In the Karoo, the kestrels prefer Scotch pines and blue gums in towns, although they are also found on some farmsteads. They seem to regard humans as less of a threat than their natural predators – cats and owls.

A dark cloud

During the grinding drought that held the Karoo in its grip from 2016 to 2021, the numbers of Lesser Kestrels in the “stronghold towns” of Hanover, Philipstown and De Aar plummeted, in some cases from many thousands to zero.

But there was a distinct uptick in numbers wherever locust swarms were seen during 2021 and 2022. Renate Advokaat, a long-time resident of Hanover, remembers:

“I saw the locusts, flying as a dark cloud, and also in a small cloud, the Lesser Kestrels above them, absolutely gorging themselves.”

The snack shop at Hanover, on the edge of the N1 highway. (Photo: Chris Marais)

Ronelle Visagie of the Endangered Wildlife Trust’s Birds of Prey Programme, also known as the Valkie Lady. (Photo: Chris Marais)

We contacted Renate again in February 2024. She estimated the numbers in Hanover had halved, to around 2,000. In De Aar, the drop was more dramatic. Numbers had plummeted from around 12,000 in 2012 to only 180 in 2024, according to a depressing tally kept by Ronelle Visagie of the Endangered Wildlife Trust’s Birds of Prey Programme.

She also reported that the Scotch pine trees behind the filling station had been cut down.

Only 10 years ago, the skies over our hometown of Cradock used to be filled with thousands of kestrels in summer. In 2024, there might have been 20 in total.

Was it because their favourite roosting trees had been chopped down? Small boys with catapults? Was it because of war in the Middle East and Ukraine? Increased pesticide use in Africa? Climate change? Bird flu? Hunters? All of the above?

Or had they simply found more to eat in a neighbouring country?

From dawn to late afternoon, you’ll see them on fences and old telephone lines. (Photo: Chris Marais)

Birds that chase summer

Of the 11,000 bird species in the world, around 1,800 are migratory, travelling along distinct “flyways” between their breeding and overwintering habitats. Most are insect-eaters or waders. In their quest for endless summer and abundant bugs, they are guided by landmarks, stars, smells, and the Earth’s magnetic field, relying on safe overnight stops and available food.

South Africa’s migratory birds include storks, cuckoos, kingfishers, bee-eaters and raptors like the Lesser Kestrels and Amur Falcons. And of course, those elegant mosquito-eating heralds of spring, the European Barn Swallows (Hirundo rustica).

Every year they face the hazards of habitat loss, power lines, wind farms, hail, storms, predators, humans with guns, skyscrapers covered in glass, blinding lighthouse beams, burning flares on oil rigs, and a dozen more dangers, including war and climate change.

Read more: Migration in a time of war – A tiny bird’s mighty trek through Ukraine battle zones

In 2024, a bitter artillery war between Russia and Ukraine spanned a 1,000km frontline and was causing unspeakable environmental damage. The turbulent Middle East is part of another important flyway.

Males have grey heads and chestnut bodies, while the females have dark speckles. (Photo: Chris Marais)

Kestrel enigmas

Until satellite tracking technology could be fitted onto Lesser Kestrels, all we knew about these birds was gleaned from irregular findings.

In 1975 and 1988, kestrels ringed in Russia were found in South Africa. Later, a Saudi prince found a bird ringed in De Aar on his desert land.

Satellite tracking showed that Lesser Kestrels that breed in Western Europe generally overwinter in West Africa, in Mali, Senegal and Mauritania. Those in Eastern Europe, the Middle East and Asia head for east and southern Africa. But much more information is needed.

There are noticeably fewer insects in the Karoo these days, probably thanks to pesticides and climate change. Perhaps we will never see the Lesser Kestrels in their tens of thousands here again. Hopefully, they have not perished, and have found richer feeding grounds somewhere else.

Or maybe they’ll be back in the Karoo in massive numbers once more, and the summer skies will be full of these small, stern kestrels, chasing insects on the wing. DM

This is a short chapter excerpt from Karoo Roads IV – In Faraway Places (360 pages, black and white photography, R350 including taxes and courier in South Africa) available from September 2024. Anyone interested in pre-ordering a first edition, author-signed copy should please contact Julie at [email protected] for more details.

The Karoo Quartet (Karoo Roads 1 – 4) consists of more than 60 Karoo stories and hundreds of black and white photographs. Priced at R960 (including taxes and courier in South Africa), this Heritage Collection can also be ordered from [email protected]

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