Austin Roberts Bird Sanctuary animals. The natural veld type of the sanctuary is mixed bushveld. Upwards of 170 native bird species have been recorded, but the presence or breeding of some have been transient, due to urbanization and other factors. Resident or visiting passerine birds include thick-billed weaver, southern red bishop, African reed-warbler, little rush-warbler and lesser swamp-warbler. Various heron species visit the reserve, including black-crowned night-heron, little bittern, green-backed heron, purple heron, black and little egret. Other regular water birds are red-knobbed coot, fulvous duck, Egyptian goose, white-faced duck, Cape teal and southern pochard. Pinioned crowned cranes and blue cranes have been released
Bird-of-paradise lek-type mating system. Others, such as the "Cicinnurus" and "Parotia" species, have highly ritualised mating dances. Males are polygamous in the sexually dimorphic species, but monogamous in at least some of the monomorphic species. Hybridisation is frequent in these birds, suggesting the polygamous species of bird of paradise are very closely related despite being in different genera. Many hybrids have been described as new species, and doubt remains regarding whether some forms, such as Rothschild's lobe-billed bird of paradise, are valid. Birds-of-paradise build their nests from soft materials, such as leaves, ferns, and vine tendrils, typically placed in a tree