Deer: Predation or Starvation

Journal Activity

Background Information:

In 1970 the deer population of an island forest reserve about 518 square kilometers in size was about 2000 animals. Although the island had excellent vegetation for feeding, the food supply obviously had limits. Thus the forest management personnel feared that overgrazing might lead to mass starvation. Since the area was too remote for hunters, the wildlife service decided to bring in natural predators to control the deer population. It was hoped that natural predation would keep the deer population from becoming too large and also increase the deer quality (or health), as predators often eliminate the weaker members of the herd. In 1971, ten wolves were flown into the island.

The data collected during this program are shown in the following table. The Population Change is the number of deer born minus the number of deer that died during that year.

DRAW IN JOURNAL & Fill out the last column for each year (the first has been calculated for you).

*Year*	*Wolf Population*	*Deer Population*	*Deer Offspring*	*Predation*	*Starvation*	*Deer Population Change*
1971	10	2,000	800	400	100	+300
1972	12	2,300	920	480	240
1973	16	2,500	1,000	640	500
1974	22	2,360	944	880	180
1975	28	2,224	996	1,120	26
1976	24	2,094	836	960	2
1977	21	1,968	788	840	0
1978	18	1,916	766	720	0
1979	19	1,952	780	760	0
1980	19	1,980	790	760	0

Graph the deer and wolf populations on graph paper (You will turn this in for a grade.) Use one color to show deer populations and another color to show wolf populations.

On the back of your graph paper - answer the data analysis and conclusion questions.

Data Analysis:

Describe what happened to the deer and wolf populations between 1971 and 1980.

Conclusion:

What do you think would have happened to the deer on the island had wolves NOT been introduced? Explain your answer.