New Species in an Ecosystem

New Species in an Ecosystem

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

Introduced Species in New Zealand

• 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.

Impact of Introduced Species

• 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.

Native Species

• 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.

Eradicating Introduced Species

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

Characteristics of Invasive Species

• 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 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.