A lone grevy’s zebra at the foot of the Matthew’s Ranges, at the Wesgate conservancy near Kenya’s Samburu national reserve. They are taller and have bigger ears and sharper stripes than their plains cousins, and are under much greater threat from conflict over scant grazing resources. Fewer than 2,500 exist, down more than 80% since the end of the 1970s, although numbers have stabilised in recent years.  Photograph: Tony Karumba/AFP/Getty Images