An Appreciation of Larks

angels in CAMOUFLAGE An appreciation of larks arks have inspired poets as glorious as William Wordsworth, John Milton and Percy Bysshe Shelley, yet most birders consider them only as bothersome LBJs. Much maligned, they are often viewed Las little more than a boring identification chore. However, larks have a history as old as Africa itself. Some members have the most remarkable survival techniques in the avian world, and they sing and display like angels. So is there more to these sombre brown birds than first meets the eye? Shelley thought so, and so do I, writes KEITH BARNES. ALBERT FRONEMAN arks are a massive identification validity of geographical races is not ost birders in southern It isn’t just the casual birder who has problems challenge and, together with pip- orthodox. Having been a sinner myself, Africa are familiar with the its and cisticolas, they wear the I can expiate my indiscretions without Spike-heeled Lark. A short- distinguishing between larks. Ornithologists have unwelcome mantle of ‘Africa’s exultation and in repentance.’ Conversely, tailed, upright lark found in LLBJs’. Most species use open habitats in Gordon Maclean wrote, ‘It is doubtful Ma wide variety of open-country habitats, been arguing about them for more than 100 years desert, semi-desert and grasslands, and are whether the matter [of lark systemat- its white outer-tail tips, stocky frame and characterised by a great deal of morpho- ics] will ever be satisfactorily resolved.’ sociable behaviour render it one of the its finder. As the bird is highly resident Above In the course of one of the more logical convergence. This is because the Maclean’s cautious view was in strong most easily recognisable and identifi- and non-dispersing, it is likely that at elaborate displays in the family, the environments they exploit are very simi- contrast to Meinertzhagen’s self-assured able of all larks. In 1965 John Beesley some stage in the past this population Rufous-naped Lark leaps, calls and claps lar, so the species often end up looking and somewhat misguided statements. discovered a small population of this must have had a contiguous distribution its wings. confusingly alike. To exacerbate the prob- The truth of the matter probably lies species near Mt Meru, Tanzania, some with the Spike-heeled Larks in southern lem, differences in plumage and form are somewhere between the two great lark 2 000 kilometres from its closest neigh- Africa. The rumblings of the Rift Valley Opposite Gray’s Lark is restricted to frequently as great within species as they men’s perspectives. bours. A short paper describing the bird and rise of Mt Kilimanjaro and Mt Meru gravel plains in the Namib. Although are between them. The advent of molecular techniques to was published and nothing more was some five million years ago seem to it strongly resembles the Ammomanes It isn’t just the casual birder who has assess the status of races and species has really thought of it. There was a theory have created a bizarre microclimate on larks of North Africa and southern problems distinguishing between larks. aided us immeasurably. Good recent work that the ice ages that dominated 100 000 the western side of Mt Meru. With rains Asia, it is in fact closely related to the Ornithologists have been arguing about involving genetics has been able to show years ago may have been responsible for being pushed in from the Indian Ocean Spike-heeled and Long-billed larks of them for more than 100 years, with many convincingly that the Long-billed Lark of the appearance of this population at the coastline, the dual rainshadows created southern Africa. inconsistent and controversial taxonomic southern Africa, once regarded as a single, ‘wrong’ end of the continent. In 1997, by these two massive mountains result treatments being proposed in the last highly variable species, is better treated as Tanzanian ornithologists Liz and Neil in a rainfall gradient that shifts from century. Two of Africa’s specialists in lark five distinct species. And it has revealed, Baker invited a team to the area to study 3 500 millimetres on the wetter, eastern taxonomy ventured vastly differing opin- for example, that the rare and highly the bird. Genetic investigation revealed side of Kilimanjaro to about 500 mil- ions on the matter. In his A Review of the localised Ethiopian endemic Degodi Lark, that this tiny population had been sepa- limetres on the dry western slopes of Alaudidae, perhaps the most flawed taxo- only described in 1971, is simply a race of rated from other Spike-heeled Larks for Meru. It is apparent that a mini-desert nomic treatise on the family ever the more widespread Gillett’s Lark. These far longer than previously appreciated, has persisted on the western slopes of produced, Richard Meinertzhagen are good instances of just how problem- probably more than two to three mil- Meru as the surrounding habitats have flamboyantly stated, ‘I make no atic the taxonomy of this group can be. lion years. It differed morphologically become wooded and moist over the past PETER RYAN apology for my methods, for I Without getting too caught up in the too, having a particularly short tail and three million years. As the world around believe that they correctly inter- mind-numbing world of molecular tax- smaller bill. it has changed, Beesley’s Lark has been pret the facts and that posterity onomy, let’s explore what these birds can It was clearly a different species and trapped within a micro-habitat: its global will concur. My view on the tell us about Africa and its history. was named Beesley’s Lark in honour of range extends only some 40–65 square 50 LARKS AFRICA – BIRDS & BIRDING AUGUST/SEPTEMBER 2009 LARKS 51 kilometres and probably no more than 100 individuals remain. It is literally on the brink of natural extinction. But many larks have incredibly small ranges and persist in minuscule patches of Larks offer us a unique snapshot of habitat. The genus Heteromirafra, compris- r ing South Africa’s Critically Endangered o d Africa’s history, as they are an ancient i r The hypothetical arid corridor that may Rudd’s Lark, Ethiopia’s Sidamo Lark and r o c Somalia’s Archer’s Lark, is the most obvi- have persisted during the ice ages and at d i group of birds that can trace some of the r ous group. With ranges scattered widely A other periods during Africa’s history obvi- across the continent, each of these spe- ously impacted on the evolution of some continent’s earliest geological events cies occupies an exceptionally small glo- larks. However, its effect was limited for bal range. Genetic work has revealed other groups, which seem to have evolved that Heteromirafra possibly represents more in situ. an ancient lineage that is slowly being MARTIN BENADIE replaced and outcompeted by more the arid corridor for dispersal and there dominant larks. are closely related species that occur at Larks offer us a unique snapshot of opposite ends of it, such as the Foxy Lark Africa’s history, as they are an ancient in the north and the Fawn-coloured Lark group of birds that can trace some of the in the south. continent’s early geological events. They are dominant in Africa’s rangelands and, hile the study of larks is of all the bird families adapted to this able to reveal intriguing habitat, they are also the most species- patterns about the evolu- rich group, with the most complex dis- tion of Africa’s arid zones, tribution patterns. All of these factors Wthese hardy little birds also have an array assist researchers’ investigations into the of features that enable them to master poorly studied rangelands. the dry country. Of the 96 species of larks in the world, Feathers are the first. Larks are dull- some 78 are found in Africa. They are coloured birds that have conservative concentrated in two main areas in par- plumage coloration and patterns. There ticular: the south-west (South Africa, is a good reason for this: they require Botswana and Namibia) and the north- camou flage. In some larks, the colour of east (Ethiopia, Kenya and Somalia), with their plumage is linked to that of the soil, 26 and 23 species respectively being and their streaking pattern is related to Opposite, top The Dune Lark has endemic to these zones. Some theories ve getation density. As rangeland special- plumage that matches almost exactly the propose that over many millions of years ists, these birds are placed under severe substrate on which it lives in the Namib these two areas were connected (maybe pressure from aerial predators, with sand-dune sea. It can survive without NANCY BELL a number of times) by an arid corridor, falcons, kestrels and sparrowhawks fre- freestanding water and derives its water and that in the process larks dispersed quently overhead. When a lark is alarmed requirements from its food. and speciated across this corridor. by a distant threat, it freezes, relying on Genetic research has turned up some its cryptic plumage to best effect. Only Opposite, middle, left The Spike-heeled fascinating evidence in this regard. It when a threat is extremely close does the Lark is a species of open grassland and seems that true desert larks did not dis- bird flush. semi-desert in southern Africa. Unusually, perse via the arid corridor. Instead, they There are two main types of lark cam- it breeds cooperatively and uses aardvark appear to have evolved from neighbour- ouflage plumage: generalised and spe- burrows for shelter in hot climates.

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