It took millions of years for bird species like moa, the haast eagle and hundreds of other natives to New Zealand to evolve, and only 700 years for humans to cause irreparable damage.
A new report in the journal Current Biology claims that it would take 50 million years to recover the diversity of bird species lost - and that's if humans were out of the picture again entirely.
Corin Dann spoke to Luis Valente from the University of Groningen about his findings.
