Throughout his life, Alex was said to be able to identify 50 different objects, count up to six, and distinguish between seven colours and five shapes. He had a vocabulary of over a hundred words and reacted with indignation when deceived.
Africa’s wildlife is doing far less ecological work than it once did. A new study suggests that the decline of birds and mammals – and in particular megafauna such as elephants – is reshaping how ecosystems function.