The numbers of elephants in Hwange National Park in Zimbabwe were counted each year between 1980 and 2001. In the 1980s, some of the elephants were culled. This practice stopped in 1986. The graph shows the changes in the numbers of elephants (±SM), the bars indicate the numbers of elephants that were culled.

a. Explain the importance of showing the standard error (SM) on the graph.

b. Describe the changes in the numbers of elephants between 1980 and 2001.

c. Elephants feed by browsing on woody vegetation and other plants. They strip off bark and push over some trees, keeping patches of grassland open, but leaving much woodland.

Explain how both high and low densities of elephants could result in reduced species diversity in national parks in Africa.

d. Explain the reasons for culling animals, such as elephants, in national parks, other than to prevent loss of biodiversity.

e. Populations of animals can also be controlled by the use of contraceptives. Explain how this method is used.

Transcribed Image Text:

50 000 40 000 - 30 000 20 000 * 10 000 nllp- 1980 1985 1990 1995 2000 2005 Year Number of elephants