The term 'ostrich cousin' refers to four different species of birds that are related to the ostrich. The first is the RHEA, which is a large flightless bird native to South America. The second is the RIA, which is a smaller flightless bird found in New Zealand. The third is the EMU, which is a large flightless bird native to Australia. Finally, the fourth is the KIWI, which is a small flightless bird native to New Zealand. All four of these species are closely related to the ostrich and share many of the same characteristics.