A method for estimating the size of a population of African penguins is the mark-release-recapture method. Suggest three assumptions that need to be satisfied for the mark-release-recapture method to be valid.
The International Union for the Conservation of Nature (IUCN) Red List of Threatened Species has classified the African penguin as endangered and it could become extinct. Suggest reasons why the African penguin has become endangered and could become extinct.
Fig. 10.2 gives the estimated numbers of African penguins in the years 1800, 1900 and 2000. Calculate the mean yearly decrease in population size of the African penguin between 1900 and 2000. Give your answer in $\text{yr}^{-1}$.
The African penguin belongs to kingdom Animalia. Outline the characteristic features of kingdom Animalia.