Acting as a kind of camp overseer was Robert Lentaaya, a Dorobo who was also a knowledgeable naturalist (see Chapter 11); both he and Luca had helped me put together the story of honeyguides leading tribespeople to wild bee nests. That first morning in the forest, Lentaaya soon exhibited his remarkable animal identification skills. He was taking me (with accompanying rifle-holding guard) along the path that meandered above the Ngeng River. Within half an hour he had pointed out Bushpig, genet and elephant tracks, droppings from lion, porcupine and Olive Baboons plus a host of birds in the trees including vivid blue, green and chestnut-coloured Hartlaub’s Turacos, black and white Tropical Boubous and delicate little chestnut and white Tambourine Doves. We heard Rock Hyraxes – correction, Lentaaya heard them, I didn’t – calling from some cliffs a little further on. So we stopped and took a good look at the cliff ledges, some of them obscured by tree branches, to see if we could spot these rodent-like creatures. This time, though, we were out of luck.
A little later Lentaaya hears some distant grunts and, after a while, I hear them too. A group of Mantled Guerezas, a species of colobus monkey. They were on the far side of the Ngeng and quite a way up the forested slope in the trees. Strikingly beautiful but uncommon animals with black and white pelage, we strain to spot them. It’s frustrating; we can see an occasional branch move quite suddenly, a glimpse of what might be part of a monkey, but no good view. Eventually the movements cease; we are not going to get a good look.
Wildlife Photography Travel Photo Gallery
I am being shown so much that I struggle to get all the names written in my noteblog. At times I have to ask Lentaaya if we can stay at the same spot for a couple of minutes to allow me to catch up with my scribbles. The wildlife riches we see on this short walk are incredible so it’s easy to assume that the forest wildlife here is in very good shape. But Luca’s research is telling him that not all is well in these remote and poorly explored forests of the Mathews Mountain Range. There are underlying problems potentially so severe that the very future of all this biological diversity is in doubt.
The forest occupies nearly 1,000 km2 of land, most of it at least 1,500 m above sea level, the higher parts over 2,000 m, with a small proportion of scrub and grassland. Uninhabited, it is a critical natural resource for communities that live around its edges providing water, honey, medicinal plants, grazing and fodder for their livestock. Respected by local Samburu community elders, the forest helps sustain their pastoral lifestyle based on cattle farming in the dry savannah surrounding the forest. And therein lies part of the problem.
‘When I first came here in 2004,’ says Luca one evening, these forests were pristine. They were the best example of mountain forest I’d seen in East Africa. They were hardly disturbed and little was known about them. But with my team for the last four years I’ve been monitoring a sample of 600 trees – a range of species and sizes -and none of them are growing. The reason is almost certainly drought.’
The same dry conditions have prevailed in recent years across huge swathes of East Africa. In past decades, a bad drought might be expected every 10-15 years. But in the last 12 years there have been four. The finger of suspicion points to global climate change. It’s making it difficult to eke out a livelihood for crop and pastoral farmers alike. Starvation is often very close. The August I was there, government-funded teams were driving from village to village slaughtering goats to reduce the burden of trying to feed them. Their owners were compensated and the meat divided up between the families in each community.
‘There’s another big problem in these forests, too, but that’s also because of drought,’ Luca told me. For a few years now the local Samburu [who, when the climate is normal, keep cattle outside the forest] have been bringing their animals into the forest where they cut down branches so the cattle can eat the leaves. Sometimes whole trees are felled, not large trees but many medium- and small-sized ones. It’s a consequence of the droughts; they have little to graze outside the forest so they are forced to make use of the trees. And the cattle trample or eat any seedling trees starting to grow; consequently, large parts of the forest have no young trees to grow up for the future.’
While it is natural for large old trees to die and fall – thereby creating a gap in which young saplings start growing – and for elephants to push smaller trees over, it’s the larger scale of the Samburu glade clearing that is worrying. It is a double whammy of drought and grazing that threatens the Mathews Forest, the two issues inextricably linked.
So Luca has started a long-term experiment within the forest. He has designed it to try and find out what biological damage this cattle feeding is causing. In 2007 his team felled all the trees in ten small experimental plots (where they then re-grow) and, over the years since, have been comparing the bird and insect species in these and in another ten similar plots left without any tree felling. It was these plots that the two Kenyan ornithologists, Lawrence and Samuel, were working in from dawn to dusk each day for a month. They had erected mist nets – fine mesh netting into which birds fly without harm but can’t get away until released – which they examined every hour to record the birds.
What this study is showing is that the cut – and thereby sunnier – gaps harbour twice as many flying insects, partly because trees exposed to sunshine produce more fruit for them to feed off. Numbers of birds and the variety of bird species has also increased in the gaps because of more fruit, more plant seed and more insects to eat. Some birds that live mainly high in the tree canopy, many of them fruit eaters, have benefitted from this change – the huge, black and white Silvery-cheeked Hornbills, for example. But others inhabiting low trees and scrub, such as the little Blue-Mantled Flycatcher, have declined. The conclusion is that if the Samburu continue felling trees for fodder and their cattle prevent any new trees from growing a lot of the birds inhabiting scrub and smaller trees in the forest will decline. Luckily, so far most of the damage is confined to the lower-lying forest; the forest much higher up the steep hillsides here is in much better condition because the Samburu herders don’t venture so high.
So what is the solution? Seemingly there’s little action being taken to address global warming because governments around the world are too obsessed with economic growth to get to grips with serious alternatives to fossil fuels. So droughts might well be a regular and more frequent event here. Living with that prospect, the practical answer might be to plant large areas of additional trees outside the existing forest and for the Samburu to be responsible in times of drought for grazing their cattle in these areas rather than using the forest itself. But trees take decades or more to mature (assuming that the frequent droughts don’t slow them to a standstill) so, in the meantime, it might be possible to identify areas of forest on its outer edges where grazing could be tolerated, keeping the forest core of the Mathews Range intact. And the Samburu could dig some ponds and build small dams on seasonal streams to hold water longer in the dry season, both for themselves and their cattle. That way, they would need to put their cattle into the forest even less.
When I was there, thunder clouds started gathering one day when we were a long way from our campsite visiting another part of these extensive forests. When the downpour started we were outside the forest in scrubby savannah with scattered trees. I have rarely seen rain like it. The whole land surface seemed awash with water under the gloomy, dark grey cloud. Even our 4WD was slithering in the conditions. Making our way back to the campsite, we approached what had been a dry riverbed when we had crossed it that morning. Not now. It had been transformed into a raging river 30 m wide or more; it’s thundering, muddy waters carrying whole trees downstream. Far too dangerous to get close to, Luca turned the 4WD on a slope, it slid as some of the track gave way beneath us and we were almost on our side in mud and water. Luckily no one was hurt; we clambered out and, after at least an hour of work stabilising the ground, got the vehicle back on four wheels and into a safer spot.
That night we wild camped. We were wet and the ground was soaked. The rain had stopped before it went dark and our ever versatile Samburu helpers cooked a meal. We slept uncomfortably. It was several hours into the next day – and the river by then was no more than 10 cm deep – before we could chance the crossing and return to our campsite. None of that vast amount of water, as far as I could see, had been harvested or held in small pools. It had all soaked away into the arid, sandy soil. It might have stimulated a bit of plant growth to nurture a little more grazing for the Samburu livestock but the vast bulk of that enormous downpour had been squandered.