Diamonds in the dust – Ghost towns of the diamond era
July 28, 2016
Of wind, air and climate change
August 1, 2016
[vc_row][vc_column][vc_column_text]Text and Photos by Hu Berry[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]
It was 1971 and the Great White Pelican was determined to breed. Propitious rains had fallen across many parts of the country, changing the Etosha Pan from a desiccated, saline desert into a vast, ephemeral but shallow lagoon.
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D eluges in the Angolan highlands had brought torrents of water flooding into the pan from the north. Referred to reverently by the Owambo as efundja (floods), these transient rivers course through the maze of oshanas and converge on Lake Oponono, the overflow is discharged into the Ekuma River, which in turn drains into the great Pan.
Initially targeting Oponono, about 3 000 pelicans began nesting on islands in June, and before long their eggs were dotting the sandbanks. The local fisher folk soon discovered this rich source of protein and started harvesting it, causing the pelicans to abandon their nests. The urge to reproduce remained unsatisfied, however, and sent the pelicans southwards towards the Etosha Pan. On its southern shore they located a tiny island near the Okerfontein waterhole. Embarking on their second breeding attempt in July, hundreds of birds crowded the small island, but it was not long before predators and scavengers were attracted by the promise of abundant food. As the pan dried, they made their way through the porridge-like clay slush, creating havoc among the nesters. For the second time the pelicans watched as their egg clutches were demolished.
Their third attempt was at a most unlikely place. Jutting 15 kilometres into the northern section of the pan, Poacher’s Point rises steeply above the surrounding bareness. In earlier years this afforded poachers an ideal vantage-point to look for game. Flamingos nested on the pan, a few kilometres from its tip, but abandoned the site as the water dried up. This is what drew the desperate pelicans, possibly because there were flamingo nests that had been vacated. From the elevation of Poacher’s Point, using a powerful telescope, I watched in amazement as the pelicans descended on the old flamingo nests. By September there were an estimated 2 500 pairs and thousands of charcoal-coloured chicks milling around. Moreover, the water had evaporated and the colony had become stranded on a dry and inhospitable pan.
Where were the adults finding their fish? Setting up camp, I watched the scene, keeping a respectful distance, because pelicans are notorious for abandoning their brood if they sense that intruders pose a threat to them. The last chill of winter was still in the air as the sun illuminated the incredible scene. Out on the glimmering, bleak surface of the pan the pelican colony created a circle of thousands of white-and-black specks as adult birds mingled with their brood. I couldn’t see any sign of water on the distant horizon. As the day warmed, heat waves began to shimmer, making the colony appear to drift above the surface.
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Then a synchronised movement of the adult birds began. Flights of up to 100 birds took off, flapping heavily in the heat as they struggled to become airborne. Flying in long skeins towards Poacher’s Point, they resembled large, overloaded aircraft. But when they reached the mainland, a magical transformation took place. They encountered rising thermals and suddenly were lifted upwards in a living spiral. Their earlier exertion ceased and the laboured beating of wings became an effortless gliding as they soared into the sky, forming a wheeling vortex of great, white bodies. Following the thermals, the pelicans soon became white dots in the heavens and then disappeared from view.
I wasn’t sure which direction they had taken, but later that afternoon, scanning the sky with binoculars, I sighted pelicans returning from the north. This time they didn’t spiral down, but moved in a straight, raking glide. Although grossly distorted by the heat waves, I could nevertheless see them being mobbed by chicks when they landed. Obviously they had brought fish back to the ravenous young, but from where?
Using a short-wave radio, I contacted Okaukuejo, requesting that a spotter aircraft be made available. Early the next day we took off from the airfield at the rest camp and headed to Poacher’s Point, landing on the pan, a good distance from the colony. At virtually the same time of day as previously, the thermal-seeking flights began. We were prepared and when the pelicans located lifting thermals, we taxied and took off, flying in wide circles around their ascending spiral. Approaching 10 000 feet, the birds peeled off and set sail, as it were, in a north-westerly direction. We throttled back and followed the flocks, looping around them. Lake Oponono came into view, exactly where the flight was heading. They settled on the water, joining hundreds of others feeding on the abundance of fish trapped in the shallows.
Back at base, we pored over a map. The minimum straight-line distance from the breeding colony on the pan to the lake was 100 kilometres. Consequently, the return trip made by the adults totalled 200 kilometres or more each time they wanted food, which was probably at least every second day. Apart from feeding themselves, the adults were also meeting the voracious appetites of the rapidly growing chicks.
Resorting to a calculator, I found that the logistics of the pelican’s airlift of fish were awesome. It is well established that an adult requires 10% of its body mass in fish every day. Adult pelicans weigh, on average, 10 kilograms and a chick increases to this weight and even higher before it can fledge. A pair of adults and their two chicks would therefore need about 420 kg of fish. When this is extrapolated by the 2 500 breeding pairs and 5 000 chicks that were present, allowing for the high, but natural mortality of 50% of chicks that perish, the total amount of fish eaten is astounding. During the four months occupying the breeding cycle, from nest-building and egg-laying to fledging, the Etosha pelican colony consumed approximately 1 000 tons of fish, air-freighting much of this over a distance of 100 kilometres! This epic event has not recurred on the Etosha Pan since.
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This article was first published in the Flamingo February 2007 issue.
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