If you thought ostriches are big, wait until you lay eyes on moa! These giant, flightless birds reached heights of about 3.5 metres and roamed the New Zealand wilds for millions of years, until they recently became extinct just about 600 years ago. Not only Moa were flightless, but also wingless birds, as they lacked even the vestigial wings, which all other species in this feathered family have.