The shell life of speedy ostrich

Ostrich and its eggs at Flamingo Land
Ostrich and its eggs at Flamingo Land

The ostrich is the largest living species of bird in the world; it is also the fastest bird, running at speeds up to 43 mph. They are native to the savannahs of Africa and are widespread across the continent, living in nomadic groups of 5 to 50 birds.

Ostriches lay the biggest eggs of any bird, around 20 times the size of a chicken egg. Ostrich eggs are a glossy-cream colour with a thick shell and are marked by distinctive small pits all over them.

Here at Flamingo Land our female ostriches are currently laying many eggs in their enclosure. At first they were laying their eggs in unsuitable places including on the concrete in their enclosure, causing some of their eggs to crack. The females were also very disinterested in their eggs once laid and didn’t incubate them. However, these eggs didn’t go to waste! They were blown to prevent them from rotting, and here at the education centre we use them during education sessions and school visits to teach children about adaptation and animal behaviour. We also use them for enrichment within the lemur enclosure; hiding food in them to stimulate natural foraging behaviour.

Luckily the females are now laying their eggs in more suitable places within their enclosure and are starting to show more interest and incubating them as their mating season has started. In the wild a female ostrich lays her fertilised eggs in a single communal nest which is a simple pit around 3m wide created by the male. The dominant female of the group then lays her eggs first and may discard eggs from the nest from other weaker females close to the time of incubation as each female can distinguish her own eggs from others. This generally leaves around 20 eggs ready to be incubated. The eggs are incubated by the females during the day and by the males during the night. This is due to the difference in colour of the male and female feathers. Females’ feathers are greyish-brown and drab in colour and therefore blend in with their sandy habitat and males’ feathers are black making them virtually undetectable at night. This helps camouflage nests from potential predators leading to greater survival.