House cats were introduced into the Australian ecosystem several years ago in an attempt to reduce a mouse plague. The cats, however, having no natural predator, multiplied and now they are harming the native bird population. Which limiting factor below best describes this Australian problem?

Part of a wetland is filled in so that new homes can be built. Which limiting factor below best describes the change in that wetland ecosystem?

The rainy season has begun in Madagascar. Trees are sprouting new leaves and flowers. Ring-tailed lemurs eat the leaves and flowers and give birth to their young during this plentiful season.



The lemur babies are sometimes prey for hawks. Which population in this example is limited by water?

A man has built a beautiful pond in his back yard and stocked it with koi and water lilies. The koi do not eat the lilies, but hide under them, making it difficult for herons flying overhead to see the brightly coloured koi. If herons see the koi, they will land and eat them. The man adds 3 wild fish to the pond and they seem to have a huge appetite for lilies. The wild fish are not brightly coloured, so they are more difficult for herons to see.



Which choice below describes the most likely change in the pond ecosystem described above?

A man has built a beautiful pond in his back yard and stocked it with koi and water lilies. The koi do not eat the lilies, but hide under them, making it difficult for herons flying overhead to see the brightly coloured koi. If herons see the koi, they will land and eat them. The man adds 3 wild fish to the pond and they seem to have a huge appetite for lilies. The wild fish are not brightly coloured, so they are more difficult for herons to see.



Which term below best describes the factor limiting the koi population?

A man has built a beautiful pond in his back yard and stocked it with koi and water lilies. The koi do not eat the lilies, but hide under them, making it difficult for herons flying overhead to see the brightly coloured koi. If herons see the koi, they will land and eat them. The man adds 3 wild fish to the pond and they seem to have a huge appetite for lilies. The wild fish are not brightly coloured, so they are more difficult for herons to see.



Which term below best describes the factor limiting the wild fish population?

On a nature preserve, a population of wolves hunts deer for its main source of food, but when the deer population is very low, the wolves will hunt rabbits instead. The rabbits are the main food source of foxes also on the preserve.

When the deer population is high, what do you think happens to the fox population?

On a nature preserve, a population of wolves hunts deer for its main source of food, but when the deer population is very low, the wolves will hunt rabbits instead. The rabbits are the main food source of foxes also on the preserve.

What do you think the limiting factor is for the fox population?

On a nature preserve, a population of wolves hunts deer for its main source of food, but when the deer population is very low, the wolves will hunt rabbits instead. The rabbits are the main food source of foxes also on the preserve.

Which species described above can experience competition with each other for a resource?

You have set up a caterpillar in a jar with a couple of leaves. You punched holes in the lid for air and set it in a sunny window. Which factor below is least likely to limit its survival?