Why are these animals pests?
Based on a representative sample of 110 Year 8 students.
Generally students found it difficult to identify the specific damage caused by a range of animal pests. In particular students struggled to correctly identify animals that stripped bark from trees, spread disease or caused soil erosion. To be able to identify specific damage caused by pests, students need to have specific contextual knowledge. It is likely that students found it difficult to identify erosion as a problem caused by animals as it is a follow on consequence rather than a direct effect. For example, rabbits eat the grass. The removal of grass then leads to soil getting washed or blown away.
Interestingly, students found it easier to identify the specific types of damage caused by ferrets and stoats than that caused by cats (even though it would seem likely that students would be more familiar with cats than ferrets and stoats). Eighty percent of students correctly identified that ferrets and stoats eat native birds and their eggs, whilst only 50 percent of students linked cats to this type of damage. Similarly 60 percent of students identified that ferrets and stoats ate native geckos and skinks compared with only 36 percent identifying cats. It would seem that either students are not aware of the potential damage caused by pets or that previous studies on endangered species have highlighted ferrets and stoats as the culprits. Both ferrets and cats are carnivores and are therefore likely to cause similar problems. Students did not seem to transfer what they knew about one type of carnivore to another.
Next steps
Identifying what we want to find out
If students find it difficult to identify particular damage caused by specific pests, the task could be repeated with students also being given the option to choose "don’t know". This could then be used as the basis of group discussions. Which pests are we sure we know about? How do we know? What further information would we need to find out to be able to answer this? NOTE: identifying what you know and what you need to learn are important parts of the Key Competency Managing self. It is also important to continue posing the question, "Why do we need to know this?"
Research
Once students have identified what they want to find out they could then, in groups or individually, research different pest animals. Visit this web site to find more information about animal pests in NZ http://www.doc.govt.nz/conservation/threats-and-impacts/animal-pests/
Once students have found out about the various animals, they can use the information to inform class discussions on:
- What makes an animal a pest? (Pest animals are introduced animals that cause damage to the natural environment or production areas such as farms. They upset the "natural balance" of the ecosystem or compete with farm animals for feed, or damage crops. In the case of farm pests the main concern is economic rather than environmental damage.)
- Why do people introduce pest animals in the first place?
- What can we do to control pests?
- Why is it important to control pests?
Discussions such as these would go some way towards addressing the Participating & contributing aim of the draft science curriculum.
Developing literacy skills in science
Being able to read charts, graphs, and tables is part of developing literacy skills in science. Once the chart of types of damage caused by animal pests has been correctly filled in this could be used as a teaching resource. Students could pose questions for each other to answer from the chart. Alternatively you could use the task below and focus on students’ ability to evaluate information.
Use the information from the chart and your own knowledge to answer the following questions.
| 1. | If you were a farmer | |
| a) |
Which pests would you most want to get rid of?
____________________________________________________________________ ____________________________________________________________________ |
|
| b) |
Why?
____________________________________________________________________ ____________________________________________________________________ |
|
| 2. | If you were setting up a bird sanctuary | |
| a) |
Which pests would you most want to get rid of?
____________________________________________________________________ ____________________________________________________________________ |
|
| b) |
Why?
____________________________________________________________________ ____________________________________________________________________ |
|
| 3. | a) |
Which pest would YOU most want to get rid of?
____________________________________________________________________ ____________________________________________________________________ |
| b) |
Why?
____________________________________________________________________ ____________________________________________________________________ |
|
These questions involve evaluation. Explain to the students that they need to use what is written on the chart, and what they already know (their prior knowledge), to help them decide which pests to choose. Make it clear that there are no right or wrong responses: what matters is that the students justify their responses.
What to look for:
- Have the students used the information in the chart to make their choices? For instance does the pest selected for question 1 cause the sort of damage that would likely be a problem for farmers?
- How do students justify their choices? Do they consider environmental impacts, economic impacts or other reasons (for example, "I would get rid of ferrets because they smell")?
The following ARB resources are about animal and/or plant pests:
School Journal Part 4 No 3 2005. To Spray or not to Spray by Trish Puharich. Learning Media Wellington. This article looks at the painted apple moth and presents a range of views on how it should be controlled. To Spray or Not to Spray? is a Level 4 English resource based on the article , and looks at students’ ability to evaluate information. This may be a useful resource to support class discussions.