In this activity, students are provided with pie graphs showing the different foods wild cats caught in two locations. Although this graph interpretation task is currently set at level 3 or 4 the following adaptation adds a more demanding level of critical thinking.
Adapting the resource
Use the two graphs to find evidence that supports or otherwise the claim that wild cats are a major reason for a decline in native bird numbers. This could be added as another question to the ARB task, but may be more effective set up as group or class discussions or debate.
The table below provides some examples of how students might use evidence to support their ideas.
| Evidence for the claim that wild cats are a major reason for a decline in native bird numbers
| Evidence against the claim that wild cats are a major reason for a decline in native bird numbers
|
| Even though birds are not the main food source, they still make up a sizeable proportion, especially on Stewart Island.
| In both graphs birds do not make up the main food of wild cats.
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| We don’t know what the bird population is. Cats might only eat the other things because there are not many birds to eat. Removing wild cats might increase the bird population.
| Both graphs show that the main food source of wild cats includes other animals that have an effect on bird life. Keeping this population under control means the wild cats are doing a good job.
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Some of the sorts of questions and justifications students might propose are shown in the table below. Now ask students to discuss what other information they might need to decide whether wild cats are a major reason for a decline in native bird numbers. Have them shape questions that could be used to gather this additional evidence and to justify why it would be useful to find answers in each case.
| Question
| Why might it be important to know?
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| What is the size of the bird population in both areas?
| If there are few birds it may be because wildcats and other predators have already caused damage. There may not be many birds left to catch so they have turned to other food choices.
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| Do the cats target particular bird species? Are the birds they eat endangered?
| We might be less concerned if they only catch introduced birds. Many of New Zealand's endangered birds are ill-equipped to cope with predators.
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| What is the population of wildcats in the area?
| If there are few wildcats, their impact won't be as great.
|
| Are there particular seasons when the cats catch birds? Does this impact on birds' breeding patterns?
| For example, if they kill adults feeding chicks, or raid nests, this increases the impact because more than one bird is affected.
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Gather & Interpret data
Use evidence
Critique evidence
Interpret representations
Engage with science
Understanding about science
Investigating in science
Communicating in science
Participating and contributing
Living world
Material world
Physical world
Planet Earth and beyond