(7) Elephants in Africa

two main reasons for elephant population decline

ivory poaching, agricultural land use

where elephants are mostly found

central, southern Africa

where elephant populations are declining

East Africa

where most East African elephants are found

nature reserves

Why Africans poach and farm

need food and money for growing poor population

ivory trade ban year

1989

group that banned ivory trade

CITES (Convention on International Trade in Endangered Species)

habitat loss effect on elephant population input

decreased food resulting on decreased young born and surviving

habitat loss effect on elephant population output

decrease in food, space results in increased death rate

where Poaching is a severe problem

Kenya, East Africa

feedback system of ivory trade

less elephants → higher ivory price

3 density dependent feedback loops

less food shortage → increase in death rates, decrease in birth rates

more predation, parasitism, disease → increase in death rates

increased intensity of social interactions → increased death rates, decreased birth rates

habitat conversion in Kenya

savannas to farmlands and deserts

park in Kenya where most elephant population is located

Tsavo National Park

Tsavo National Park annual rain

less than 500 mm

what do elephants eat which requires rainfall

vegetation

habitat size needed to maintain viable elephant population

1000 mi²

how many major nature reserves in Central/Southern Africa greater than 1000 mi²

7 out of 20

density-dependent factors in elephant population

dense population → more disease
dense populations → more fighting → more death, emigration, less birth