Background Information

Ecosystems are often difficult to understand because they usually include interactions between a large number of species. Isle Royale is different. It is a relatively simple island ecosystem, located 24 km from the shore of Canada in Lake Superior.

While there are many types of small animals on the island, and almost 20 types of mammals, only two species of the mammals that live on the island are relatively large. These are the wolves and the moose. On this island, wolves are the only predator of moose, and moose are essentially the only food for wolves.

To understand nature, it helps to observe an ecosystem where human impact is limited. On Isle Royale, there are no towns and people do not hunt wolves or moose or cut the forest. It is a very rare place on the planet where wolves, their prey, and the plants that support the prey are all left unharvested by humans. Isle Royale is remarkable, because nature runs wild there.

Moreover, because the wolves and moose on Isle Royale are isolated from the mainland by the surrounding water, they are unable to leave and new individuals are unable to come to the island except in very rare cases.  Since scientists began observing the island in 1959, only one migration has occurred, which was a single wolf joining the island.  Therefore, any population changes we might observe therefore are not the mere wanderings of wolves and moose to or from the island.

You're going to make some predictions about how the size of the wolf and moose population might change over time.