1. Impact of alien species on the environment
G.3.4, G.3.5, G.3.6

2. Endemic species versus invasive alien species
Interspecific competition (cf intraspecific competition)
Predation
Species extinction

3. Kudzu Very fast growing invasive plant
Endemic in Japan and was introduced to USA in 19th century
Very fast growing invasive plant

4. Zebra muscles Introduced from europe to USA in 1980s

5. Non-endemic grey squirrels killed and out-competed the endemic red squirrels in the uk forests
RED SQUIRREL Sciurus vulgaris
Average adult weight: Summer 260g Winter 285g Length: Head and body 22cm Tail 18cm
GREY SQUIRREL Sciurus carolinensis Average adult weight: Summer 480g Winter 600g Length: Head and body 26cm Tail 22cm

7. Used as an alternative to pesticides and herbicides
Biological control
Using natural predators of invasive, non endemic species, to control it spread
Used as an alternative to pesticides and herbicides

8. Advantages of biological control
It is highly specific to a particular pest.
It can be cheap in the long term.
It can provide a long-term solution to a pest problem
There is no environmental contamination with chemical pesticides
Pests do not become resistant

9. Lady birds and aphids

10. Prickly pear and Cactoblastic cactorum (moth)
From America to Australia
Moth introduced as a biological control
No cactus native to australia, so introduction of the herbivore posed no threat to the environment

11. Ragwort and biological control
Cinnebar moth lavae

12. Dangers of biological control
Co-lateral damage and ecological disasters caused by biological control measures

13. The cane toad Bufo marinus
The cane was introduced to Australia from S America to control a sugar cane pest, the cane beetle
The toad is a having a significant effect on Australian endemic species

14. A flightless bird endemic to the islands of Mauritius
The dodo: Extinct
A flightless bird endemic to the islands of Mauritius
Dodo facts
It became flightless because of the ready availability of abundant food and absence of predators on Mauritius.
The last recorded sighting of a Dodo was in 1662
It became extinct because it was preyed on by sailors and other invasive alien species, such as cats, dogs, pigs and rats