Facts: Ostrich Egg Facts: 15 centimetres (5.9 in) long, 13 centimetres (5.1 in) wide, and weigh 1.4 kilograms (3.1 lb). They are glossy cream-coloured, with thick shells marked by small pits. The eggs are incubated by the females by day and by the males by night. This uses the colouration of the two sexes to escape detection of the nest, as the drab female blends in with the sand, while the black male is nearly undetectable in the night. The incubation period is 35 to 45 days.