Year 8 Science · Unit 1 · Lesson 24

Population Changes and Introduced Species

Foundation Worksheet

Name

Date

Class

Learning Goals

Sort introduced species scenarios into direct impact, indirect impact, and control method categories.
Use key vocabulary to describe how invasive species disrupt native ecosystems.
Give specific Australian examples of introduced species and their effects.

Warm Up

Sort it!

Write each item from the pool into the correct category box below. Each item describes something related to introduced species in Australia.

Rabbits eat native grasses, leaving soil bare Cane toads poison quolls that try to eat them Feral cats hunt bilbies directly Myxomatosis virus released to kill rabbits Rabbits outcompete wallabies for food Predator-proof fences around wildlife sanctuaries Foxes kill native ground-nesting birds Calicivirus released to reduce rabbit numbers Sea of bare ground from rabbit grazing causes soil erosion 1080 poison baiting to reduce fox populations

Direct Impact

Indirect Impact

Control Method

Your Turn

Fill the gap

Choose the correct word from the word bank to complete the passage. Not all words will be used, two are distractors.

invasive introduced predator competition myxomatosis toad ecosystem native adaptation

An species is one that has been deliberately or accidentally brought to a region where it did not originally live. When such a species has no natural in its new environment, its population can grow rapidly and it becomes . This explosive growth often harms species through two main mechanisms: direct predation and for food and habitat resources.

Rabbits were introduced to Australia in 1859 and their numbers exploded to billions, devastating native vegetation. To control them, scientists introduced the disease in the 1950s, which dramatically reduced rabbit numbers. The cane , introduced in 1935 to control sugar cane beetles, is toxic to many Australian predators, disrupting the entire northern Australian .

Show What You Know

1. A rabbit has no natural predators in Australia. Explain why this causes their population to grow so rapidly. Use the terms "birth rate" and "death rate" in your answer.

Recall 2 marks

2. Why are feral cats considered so damaging to Australian native animals? Give ONE specific example of a native animal they threaten and explain the impact.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?