One possible explanation for the lack of native mammals in New Zealand is the country's isolation. New Zealand is located over 2,000 kilometers from the nearest landmass, making it difficult for mammals to naturally reach the islands. As a result, there is a lack of mammal species that could have evolved to fill ecological niches, resulting in the dominance of native birds and plants in the ecosystem. Additionally, the presence of introduced mammal species like rats, possums, and stoats has put pressure on native species, further limiting the ability of mammals to establish themselves in the ecosystem.
