There are more than enough flying mammals involved in the annual bat migration to literally darken the dawn and dusk skies over Kasanka, a remote swamp in Zambia. The Kasanka bats arrive to feast on fruits, and in turn provide a feast for raptors and crocodile. You’ll (ahem) go batty at the enormity of this unparalleled wildlife spectacle.
When we found out that Halloween would coincide with a full moon, it seemed that the stars had aligned for our diversion to Kasanka on our Zambia safari. Even by Zambian standards, Kasanka is remote and little-known, but acting on a tip-off we headed there to witness a very different kind of wildlife event.
Antelope movements between the Masai Mara and Serengeti are known as the Great Wildebeest Migration, so we weren’t sure how to describe a migration with not one million, but 10!
Quite simply, it’s the largest mammalian migration on earth. The statistics are staggering: giant straw-coloured fruit bats, each with a 1m wingspan, fly hundreds of kilometres per night across the central African rainforest canopy to feast in Kasanka. During their three months’ stay, they consume an estimated 330,000 tonnes of masuku and waterberry fruits – equivalent to more than 30kg per bat!
Staying at Wasa Lodge, we were effectively in the arrivals hall of this massed flight. Although it was outshone by more luxurious lodges on our Zambia safari (there aren’t any here in Kasanka), Wasa was extremely comfortable and the staff gave us a typically warm Zambian welcome as we checked in.
Our chalet overlooked the lake, and on our first morning we climbed up to the lodge’s treetop platform to tune in our safari ears. We heard the cries of fish eagles – Zambia’s national bird – and the contented chortling of hippo. Also, a constant background squeaking, like thousands of rusty hinges opening and closing. We hugged each other in excitement: the bats were back in town!
After a morning ‘Wasa Walk’ with our guide to take a closer look at the puku and try and spot a sitatunga, we spent a relaxing day birdwatching from the lodge. In late afternoon, the time came for us to set off on the short drive to the Musola stream where hundreds of thousands of bats had spent an even more chilled day, hanging around in the red mahogany and quinine trees of the ‘Mushito’ evergreen forest.
The skies had cleared after a brief afternoon rain shower (it’s the rains which bring the bats, in effect, as they come for the fruits which ripen in the rainy season). We settled into position in the newly refurbished BBC hide (yes, you guessed it, a certain Sir David Attenborough had been here before us).
Although it was late afternoon and the light had softened, we were slightly concerned that we couldn’t see any bats at all. And then we realised – what we had taken for large dark fruits hanging in bunches were in fact the creatures we’d come to see. There were masses of them, all patiently waiting for dusk. An occasional squeak or outstretched wing were the only clues as to what was about to happen.
The bats weren’t alone in the trees; their roost proved to be another great spot for birdwatching, and in just a few minutes we saw kites, vultures and hobbies. They were waiting, too, but with the more sinister intention of snatching unwitting bat snacks on the wing.
In the grey light of dusk, first one, then two, then 200 bats all took to the air. The volume of squeaking rose to a near-deafening level, and suddenly the air was full of black shapes. Their languid flapping belied their speed as more and more bats launched themselves into the evening sky. Everywhere we looked, there were translucent wings and small furry bodies zooming this way and that, and seemingly hastening the onset of night by blocking out what was left of the sunlight.
Our cold beers languished forgotten in our hands – we were completely mesmerised by the scene unfolding itself all around us. ‘Unfolding’ was exactly the right word, as bat after bat unwrapped itself and dropped from its perch, before gaining height with a few powerful wingbeats, and heading off into the dusk.
Then it was the turn of the raptors to join the melee – we saw an African hawk-eagle deftly snatch a bat with both feet and carry it off. Right on cue, a huge silvery moon (of the kind you only really see in Africa) rose and bathed the scene in slightly unreal light. We were reminded of the Batman movies as thousands of chiropteran shapes were silhouetted against the pale disk of the moon.
With bats flying in every direction, it was hard to know where to look, or to follow any one particular bat for more than a few seconds. We agreed that this was one of the most memorable wildlife experiences we’d ever had, and later, round the fireplace back at the Wasa Lodge, we enjoyed reliving what we’d seen with our fellow guests. The fire crackled, a hyena whooped, but just for a moment, there wasn’t even a thin bat’s squeak to be heard.