What would be a probable explanation for why there are many endemic plants and birds in new zealand but no native animals

New Zealand islands are formed by volcanic activity, so they are not as old as the closest continents so that they could have some animals that evolved from the prehistoric species (especially the mammals). So when the islands formed, they were far away from the closest continent, Australia, and only the birds and the plants (through their seeds in the winds) managed to get in here and develop unique characteristics.

Mexico has a host of environmental problems, including significant chemicalpollution  from factory discharges and waste dumping, but the main threat to itsbiodiversity  probably stems from  deforestation  and other natural habitat losses. forest habitat is lost for a number of reasons