The Book of Job (chapter 39, verse 16) says of the female ostrich (Struthio camelus): 'She is hardened against her young ones as though they were not hers'. Job puts this down to stupidity but the real reason is safety in numbers. The senior female in a group is the first to lay her 1.5kg eggs, whereupon other females are attracted to the nest and lay their own eggs in it. The lead pair in the group then raises the resultant brood of 10-15. They kidnap young birds until they have a family of up to several hundred. This may make donor parents look uncaring but individual chicks are vulnerable to predators and a group can protect itself.
The ostrich is the largest living bird and the world's fastest two-legged animal, running at up to 70kph. It was reduced to tiny numbers in the eighteenth century due to demand for its feathers. Nowadays, ostrich farming provides enough meat, leather and feathers to meet consumer demands and wild birds are left to flourish.