Presa

In a healthy ecosystem, prey and predatory species maintain a balance through predation, which helps sustain the ecosystem. Prey species can also be predators. For instance, Pacific salmon are preyed upon by bears and other animals, but they also prey on krill and small fish like anchovies.

What is a key characteristic of a healthy ecosystem?

• No predators present

• A balance between prey and predators

• An imbalance between prey and predators

• Only prey species exist

How does predation help in an ecosystem?

• It helps maintain sustainable prey populations

• It makes prey species extinct

• It reduces the number of prey species

• It increases the number of predators

Which of the following is an example of a prey species that also acts as a predator?

• Anchovies

• Pacific salmon

• Krill

• Bears

What do Pacific salmon prey on?

• Birds

• Bears

• Krill and small fish

• Large mammals

Which animals prey on Pacific salmon?

• Bears and other animals

• Anchovies

• Small fish

• Krill