Bird Migration through an East African Hot-Spot

September is the first of the happy months for many European birders living here in East Africa. October will get even better whilst late November is probably best overall. However the greatest volume of migrant passerines pours south across the region during early December, overnight and largely unseen.

Nevertheless it is during September that the first wave of Palearctic passerines arrives in Tanzania. That is with the exception of a few Barn Swallows and fewer House Martins who flicker through a little earlier. It is in anticipation of both relief and considerable delight that I look forward to seeing my first Northern Wheatear, crisply-margined and fresh, who will appear at the Equinox, having flown from a rock-fissure nest hidden as far from here as Arctic Canada. Yes, I am imagining it now, hopping about on a dusty lawn of goat-nibbled pasture, probably at one of the innumerable building sites that are cropping-up around the western perimeter of my town: Arusha.

I anticipate my first returning Willow Warbler. Likely as not that bird will be a bright yellow juvenile, gleaning tiny insects from the canopy of a tenderly leafing acacia on some spring-like knoll, also somewhere local. And already I imagine savouring the first Garden Warbler of the return. He (or is it she?) will be singing away quietly, likely as not invisible, maybe in the brakes of Lantana camara in our own garden – it’s an increasingly woodland-edge this “Wilding Wedge”! Their song in Africa is more subdued than that which you hear from the same birds freshly arrived, on those softest of late May mornings. Morning in a breeding spinny in the verdant European spring, which is probably Russian in the case of this Sylvia borin. Furthermore, to be honest, I can hardly wait a month for the first Spotted Flycatcher to drop in here,likely it will  be headed a long way farther south. A ‘modest species’ in character whose sub-song, employed in the winter quarters, might be missed entirely unless you are wedded, as I am through years of sweet acquaintance, to springs long ago ‘up in Europe’. For then it was a familiar garden bird. So I’m still in thrall to that softest of “sip–ticks”.

Most of all I look forward to that afternoon when the first bejewelled shower of European Bee-eaters cascades through the garden. They’ll be seeking a safe roosting site in the Grevillea silky oaks. The commonest of the shade trees, planted in the coffee farms of the valley below, visible from our crumbling pile of a bungalow on this hill. The valley that separates the mighty cone of Mount Meru from the four softly rounded peaks of Monduli. It’s a fine valley, a broad open space, up to 10 kilometres between big volcanic mountains. And as such the Monduli gap provides the perfect gateway through which unknown, yet still vast, numbers of migrant birds, both Afro-Palearctic and Afro-tropical, are funnelled south and north each season.

A few kilometres to the north of “the Gap”, beyond the Lammergeier village of Oldonyo Sambu, this gateway opens out into a sub-desert steppe, the location of Lark Plains. Here lives the rarest bird on mainland Africa the Beesley’s Lark, or surely it’s better these days to refer to it as the “Maasai” Lark. Together with another little brown lark, found only in a small area of Southern Ethiopia, this is the African bird that is most likely to disappear, die-out, become extinct, within the next few years.

I know because I was there guiding just last week with a gentleman, called Steve, from Australia and we watched two of the habituated “Beesley’s” foraging in what has become the core of the “protected area”, at the dead centre of the plain. Thanks to an initiative pushed-along by the indefatigable Daudi Peterson of Dorobo, the villagers of Engikaret, whose live stock graze the plain, make a little money from the foreign visitors who come to “twitch” these larks. As a result the centre of the dusty plain is less overgrazed, less wrecked, than is the acacia studded periphery. Here some nameless NGOs (who really should know a lot better) inadvertently have encouraged widespread habitat degradation, over the past ten years, by drilling boreholes so that “incoming pastoralists” can share the water with their herds of sheep and goats 24-7. This leaves their long suffering wives and daughters a lot more time, and enough energy, to lop and fell many of the bigger Acacia trees that grow around the plain. Fell the trees not simply for cooking-wood but in order to make charcoal. The Commiphora wood is soft and green and sappy – and hence of little use. So the acacias are felled not for domestic consumption, but as a way of cashing-in on, what has become, the “natural capital” of the recently arrived residents of the plain. In turn this cash injection allows the men-folk to buy more sheep and goats – semi-liquid capital on the hoof – which are fed back into the wider system! Fewer and fewer trees, more space between things, more ‘alien weeds’ instead of productive pasture, more dust above all, this is the compound result of such mal-investment, ecologically speaking.

These hilly areas around the periphery of the plain, land with scant rainfall, continue to support a remarkably rich bird community. Sadly the numbers of most species, if not all of them, are on a variety of gradients of decline. A few species are seemingly increasing with the attrition of this woodland into overstocked range land. Small ones these, birds such as an indomitable, “Bird of the Future”, the dust-loving Fischer’s Sparrow-Lark. Others who remain widespread, and even appear to thrive, in such low-stature scrub include the strikingly white-browed intercedens form of Foxy Lark, a recent split from what is still called Fawn-coloured in the ever popular “Gullible Guide to the Birds of East Africa”.

The area supports not only several scarce and interesting residents such as Buff-crested Bustard, the dapper and extremely unobtrusive Bush Pipit and the range-restricted Red-throated Tit, but also a community of mostly Central Asian Palearctic migrants near the southernmost limit of their wintering range. Lovely evocative birds such as the Eurasian Rock Thrush, Pied Wheatear, Rufous Scrub Robin, Irania (White-throated Robin), Upcher’s and Barred Warbler.

Whilst some habitat disturbance and even ‘degradation’ in the form of sustained and intense grazing pressure – by scrawny domestics in place of sleek wild ungulates – upon a savanna woodland floor appears essential for the well-being of many of these birds, the almost complete removal of the taller acacias, from this Acacia-Commiphora so-called Somali-Maasai biome, over ever larger areas hastens the ‘departure’ of an ever increasing number of species from this wonderful bird community. The birds are getting just that little bit harder to find, and to show to others, not just with each successive season but with each trip that I make to what remains nevertheless my favourite of all these local patches – top spots for birders, hot spots for naturalists.

As always I would like to extend my sincere thanks to the following photographers: to Anabel Harries for the Buff-crested Bustard, Martin Goodey for the great big Northern Wheatear and little tiny fly, for the goats on a hillside and an Acacia sunrise, to Steve Clark for the intact Acacia woodland (it’s just above the plains), for the Red-throated Tit and the Foxy Lark and to Clare Kines of the Arctic for this year’s “Canadian” Northern Wheatears (July 2014) – a father and child.