4.3 Intruders in an Ecosystem
Cambridge Lower Secondary Science Stage 8
Biology
What are native
species and
invasive species?
Imagine the ecosystem of the arctic ocean.
What would happen if a new species, which ate fish,
entered the ecosystem?
The species would have no predators and would
quickly reproduce.
Soon, there would be less fish for seals and arctic
birds, which would starve and die.
In this case, the new species is called an invasive
species and the seals and birds are native species.
Definitions
Native Species
Invasive Species
A species that occurs naturally in a specified area
where it is found without human intervention.
A species that does not naturally occur in a
specified area where it is found.
Introduced species in New Zealand - Pg 140
Read the extract on page 140 and answer the following questions:
1.
2.
3.
Name 3 native species of New Zealand [including extinct ones]
Name 4 invasive species of New Zealand
Explain 1 impact of any invasive species on the local ecosystem of New Zealand in 10-15 words.
Introduced species in New Zealand - Pg 140
Questions:
1.
Name 3 native species of New Zealand
a.
2.
Name 4 invasive species of New Zealand
a.
3.
Laughing Owl, New Zealand Thrush, Kiwi
Sheep, Rabbits, Stoats, Rats
Explain 1 impact of any invasive species on the local ecosystem of New Zealand in 10-15 words.
a.
b.
Rats have eaten bird’s eggs and defenceless young birds.
Stoats have bred rapidly and have made many New Zealand birds extinct.
Pg 141 - Questions
Question
Are humans native species?