ardetta

The pretty ardetta (Herodias bubulcus), of a light yellow colour when at rest, but seemingly of a pure white when flying, takes wing, and sweeps across the green grass in large numbers, often showing us where buffaloes and elephants are, by perching on their backs.

A Popular Account of Dr. Livingstone's Expedition to the Zambesi and Its Tributaries 2004

The pretty white ‘ardetta’ is seen in flocks, settling on the backs of large herds of buffaloes, and following them on the wing when they run; while the kala (‘Textor erythrorhynchus’) is a better horseman, for it sits on the withers when the animal is at full speed.

Missionary Travels and Researches in South Africa 2004

The pretty ardetta (_Herodias bubulcus_), of a light yellow colour when at rest, but seemingly of a pure white when flying, takes wing, and sweeps across the green grass in large numbers, often showing us where buffaloes and elephants are, by perching on their backs.

A Popular Account of Dr. Livingstone's Expedition to the Zambesi and its tributaries And of the Discovery of Lakes Shirwa and Nyassa, 1858-1864 David Livingstone 1843