Larks are a unique, mostly African, group of birds. One of my favourites is Namibia’s only true endemic, the aptly-named dune lark Calendulauda erythrochlamys.
Its global distribution is entirely restricted to the oldest desert in the world, the Namib – between the Kuiseb River in the north and the Koichab River in the south. Even in this limited range they are picky about where they reside – no bare sand dunes; typically sparsely vegetated dunes punctuated with Namib dune bushman grass Stipagrostis salbulicola and !Nara melon bushes Aconthosicyos horridus.
I recently had the good fortune of spending several hours at Sossusvlei with this lark species. Being in the Namib dunes at first light and respectfully tracking these birds by their distinctive spoor or by their rattling calls emanating in the still morning air, could just be a birding experience hard to beat.
I was amazed at how quickly the bird moved across the dunes in search of prey. Its noticeably long legs delivered long strides of around 20 cm as measured between tracks. It fed on invertebrates and seeds – frequently digging in the soft sand, jumping up and gleaning insects from grasses, chasing down prey with startling agility and even making aerial sallies after insects off dune crests. It was November, so daytime temperatures rose very quickly and the bird made the most of the favourable foraging conditions, probably explaining its heightened activity. On quite a few occasions, its hapless victims were striking Namib dune ants Camponotus detritus which the lark caught and consumed with vigour.
Dune larks have evolved perfectly to survive in such an arid environment – their water needs mostly met through their food items, their cryptic plumage perfectly matching the Namib and energy conservation achieved through reducing metabolic rate.
This specific photographed individual also had a longer bill than I had previously noted for the species. Reading up on the Karoo Lark Complex of which dune lark is a part, it was interesting to note that the male's bill can be up to 20% longer with many dune larks having long, slender and slightly decurved bills just as this bird.
A call heralded the arrival of two other dune larks and we took it as a sign to leave the birds in peace. Thankfully almost its entire population is within the boundaries of the Namib-Naukluft National Park so it is not as threatened as some other highly localised lark species in Africa.
By Martin Benadie. Bird photographed in Sossusvlei area, Namib-Naukluft National Park, Namibia