The Invasive Threat
The Invasive Threat is a Grade 7 science topic from Amplify Science (California) Chapter 4: Science Seminar on the Orange-Bellied Parrot, examining how invasive species like feral cats disrupt native ecosystems. Students analyze food web models to understand how introduced predators affect population stability and threaten endangered native species.
Key Concepts
The ecosystem includes both native species and invasive species (like feral cats) introduced by humans.
Changes to one population can directly or indirectly affect others. Students analyze how these new invasive populations fit into the web and disrupt the native parrot's stability.
Common Questions
What is an invasive species and how does it affect ecosystems?
An invasive species is one introduced by humans into an ecosystem where it did not naturally exist. It can outcompete native species for resources or prey on them, disrupting population balance.
How do feral cats threaten the Orange-Bellied Parrot?
Feral cats are an invasive predator introduced to the parrot habitat. By preying on the parrots, they increase the death rate, which can destabilize the population and push the species toward extinction.
What do Grade 7 students learn from the Orange-Bellied Parrot case study?
Students construct food web models showing native and invasive species interactions, analyze how changes in one population cascade through the web, and evaluate evidence to determine why the parrot population declined.
How are food webs used to study invasive species?
Food webs map the feeding relationships in an ecosystem. By adding an invasive species to the model, scientists can predict which populations will be directly or indirectly affected.