Land of the Birds

Free from terrestrial mammalian competition and predatory threat, birds occupied or dominated all major niches in the New Zealand animal ecology because there were no threats posed to their eggs and chicks by small terrestrial animals. Moa were grazers, functionally similar to deer or cattle in other habitats, and Haast’s eagles were the hunters who filled the same niche as top-niche mammalian predators, such as tigers or lions.

— A Wikipedian