New Zealand’s natural world is so unique that it has been listed as a biodiversity hotspot. Unfortunately, introduced species, including the big three predators threaten that.
The islands of New Zealand evolved for millions of years in the absence of mammalian predators. The lack of these predators allowed the native species to evolve in unique ways. Many of the birds became flightless, big, small, or became naive. Some of these traits make them easy prey to introduced species. These non-native species are having a serious impact on the native species.
The Big 3 Predators
People have introduced plants, birds, and many mammals. These introduced species have all impacted the natural world in different ways and to varying degrees. Approximately 51 species of mammals have been introduced to New Zealand, with 28 still living here. This includes herbivores and carnivores.
Some introduced species, such as stoats, are voracious predators. Others, such as rabbits seem more benign, but are equally destructive in their own way.
The biggest threat to the natural world of New Zealand today comes from the big 3 predators. These three predators are stoats, rats, and possums.
The Big 3 Predators – Stoat
Stoats are voracious predators. These mammals were brought to New Zealand on purpose by people to help control introduced rabbits in the 1860s and 70s. Unfortunately, letting stoats go in the wild has not turned out so well. Stoats eat rabbits, mice, birds, and invertebrates (bugs).
The Big 3 Predators – Rat
There are four species of rats in New Zealand, but it’s the ship rat that causes the most harm and is the most widespread. These arrived in the first European ships that came to NZ in the 1800s and were widespread by the 1880s. Ships rats eat birds, frogs, reptiles, and invertebrates (bugs).
The Big 3 Predators – Possum
The brush-tailed possum was introduced to New Zealand from Australia between 1858 and 1870. They were brought here for their fur and now there are millions of them. They are mainly herbivores, threatening native trees, but also eat invertebrates, bird eggs and baby birds.