The Sumatran orangutan, $\textit{Pongo abelii}$, occurs only on Sumatra, Indonesia. Fig. 1.1 presents a Sumatran orangutan. It spends most of its life in trees and is highly vulnerable to habitat destruction. Table 1.1 gives the area of natural forest in Sumatra and the numbers of orangutans in $1985$ and $2016$.
(a(i))[1]
With reference to Table 1.1, state how the area of natural forest is related to the number of orangutans.
(a(ii))[2]
Calculate the mean annual decrease in orangutan numbers between $1985$ and $2016$. Show your working. Give your answer to the nearest whole number.
(a(iii))[1]
Use your answer from (a)(ii) to estimate how many years after $2016$ it will take for the Sumatran orangutan to become extinct in the wild, if conservation work is unsuccessful.
(b)[2]
Suggest two reasons for the decline in Sumatran orangutan numbers, other than habitat loss.
(c)[3]
Outline the role zoos can play in conserving the Sumatran orangutan.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “a positive correlation between forest area and orangutan population size” …