Name: ______Date: ______Hour: ______
Wolves and Moose of Isle Royale
Directions: Graph the predator-prey cycle of the wolves and moose on Isle Royale using the data below in your composition book. Use dual y-axes to show the trend, since moose numbers are so much greater than wolf numbers. The left y-axis should be in increments of 10, from zero to 50 for the wolves. The right y-axis should be in increments of 500, from zero to 2500 for the moose. Connect the dots using the crayons, one color for the moose populations, and a second color for the wolves. Be sure to label and title your graph, as well as make a key.
Year / Wolf Population / Moose Population1959 / 20 / 563
1966 / 26 / 765
1969 / 17 / 1,268
1970 / 18 / 1,295
1973 / 24 / 1,435
1977 / 34 / 1,143
1978 / 40 / 1,001
1981 / 30 / 863
1982 / 14 / 872
1983 / 23 / 932
1985 / 22 / 1,115
1990 / 15 / 1,216
1995 / 16 / 2,422
1996 / 22 / 1,163
1998 / 14 / 699
2001 / 19 / 900
2002 / 17 / 1,100
2003 / 19 / 900
2006 / 30 / 450
Directions: Answer the following questions in your composition book.
1. Can an ecosystem support an infinite (unlimited) number of moose? Why or why not?
2. If wolves did not live on Isle Royale, what main limiting factor would determine the amount of moose the island could support?
3. What other limiting factors may influence population numbers?
On Isle Royale, the moose have a predator – the wolf. Use your graph to answer the following questions in your composition book.
4. When the moose (prey) population increases, what happens to the wolf (predator) population? Why?
5. What causes the moose population to decrease? When this happens, what happens to the wolf population?
6. Why is this interaction between predator and prey called a cycle?
7. Why is this cycle so easily studied on Isle Royale?
Neubecker