New Species in an Ecosystem

Study Notes

A new species arriving in an ecosystem can affect the interactions between species and their environment.

New Zealand was separated from other land areas 66 million years ago, resulting in unique species development.
Before humans arrived, there were no predatory mammals in New Zealand, and native birds nested on the ground without fear of predators.
Humans introduced non-native species, such as rats, sheep, and rabbits, which affected the ecosystem.
Rats prey on birds' eggs and young, while stoats, introduced to control rabbits, have spread and hunt native birds, including kiwi chicks.

Stoats have made several native bird species extinct, including the laughing owl and the New Zealand thrush.
Scientists estimate that 53 native bird species have become extinct since humans arrived in New Zealand.
Introduced invasive species are a major cause of extinctions, alongside human hunting and killing.

A native species is a species that is naturally found in a particular ecosystem or region.
Examples of native species in New Zealand include kiwi, laughing owl, and New Zealand thrush.

It is difficult to eradicate an introduced species once it has settled into a new ecosystem due to its adaptation and spread.

Invasive species can cause problems in new ecosystems because they are not native and may outcompete native species for resources.
Examples of invasive species include stoats in New Zealand and buffelgrass in the Sonoran Desert.

Buffelgrass is a non-native plant species that was introduced to Arizona in the 1930s.
It grows in dense patches, taking water and nutrients from the soil, and can affect native species in the desert.