The lone egg below belongs to the largest extant bird on Earth, the ostrich (Struthio camelus). When fleeing from a predator, ostriches will sometimes stress drop an egg, lightening the load to increase the speed of their breakneck sprint across the savanna. Ostriches can attain speeds of over 40 mph and together with their lethal kicks they make for a challenging prey item. They are shy in human presence, and we often spot them in pairs running steadily into the horizon. Yesterday we encountered a group of three on foot, and it was astonishing to observe how far they travelled between the valleys in just a few minutes. The abandoned eggs unfortunately do not have a chance of survival, but they will serve as a scrumptious snack to hyenas, jackals, and the like. What is so astonishing is the thickness and weight of the egg. It’s as if the egg had been made out of marble with small circular depressions. Even after a four foot drop from the ostrich’s cloaca (basically like falling from a moving vehicle), the egg remained completely unscathed. Ostrich nests are built as a simple large clearing of dirt, where 20-30 eggs may be present at a time. Nests are communal, with multiple females depositing eggs in the same location, though those laid by the dominant female are given preference and others may be ejected. Both sexes provide parental care for the eggs, incubating them and providing protection from predators.
All ostriches photographed after pursuit