Please answer a question about the following article about Hunting:

New Zealand has a strong hunting culture. The islands making up New Zealand originally had no land mammals apart from bats. However, once Europeans arrived, game animals were introduced by acclimatisation societies to provide New Zealanders with sport and a hunting resource. Deer, pigs, goats, rabbits, hare, tahr and chamois all adapted well to the New Zealand terrain, and with no natural predators, their population exploded. Government agencies view the animals as pests due to their effects on the natural environment and on agricultural production, but hunters view them as a resource.

What were the the only land mammal in New Zealand?
bats