Giraffes: Young male giraffes engage in dominance displays involving ‘necking’, where the neck and horned head of the animal are used as a weapon. These displays often end in courtship and climax. A trebuchet is a medieval siege engine: a long, counterweighted beam is attached to a fulcrum, and the machine functions like a catapult.

Black Rhino: According to J.A. Hunter, writing in the 1950s, the Ngorongoro crater was once home to thousands of black rhinos. In the first half of the twentieth century black rhinos were hunted across their African range; some were machine-gunned from the back of moving vehicles. In the twenty-first century there is still a great demand for rhino horn, which is used in the making of ceremonial Arab daggers as well as in some forms of Eastern medicine. At the last count there were twenty-six black rhinos remaining in the Ngorongoro conservation area. The ‘fever tree’ is a species of acacia: early travellers erroneously believed that the tree spread malaria; in fact the disease was transmitted by the mosquitoes that lived in the vicinity of the trees.

Crater Road: Obsidian is volcanic glass.

Swallows: European swallows overwinter south of the Sahara. During the migration, many birds die of starvation or exhaustion.

Cheetahs: The distinguishing features of the cheetah include the ‘tear-tracks’ found under the cheetah’s eyes. Titian’s ‘Bacchus and Ariadne’ (1520–23) hangs in the National Gallery, London (www.nationalgallery.org.uk/paintings/titian-bacchus-and-ariadne)

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