Herds and Reproduction Ostriches live in small herds that typically contain less than a dozen birds. Alpha males maintain these herds, and mate with the group’s dominant hen. The male sometimes mates with others in the group, and wandering males may also mate with lesser hens. All of the group’s hens place their eggs in the dominant hen’s nest—though her own are given the prominent center place. The dominant hen and male take turns incubating the giant eggs, each one of which weighs as much as two dozen chicken eggs.