Orangutan at Chester Zoo, UK.
The Sumatran species of orangutan is critically endangered and the Bornean species of orangutan is endangered according to the IUCN Red List of mammals. This is due to a combination of habitat destruction (as tropical forest is converted to oil palm plantations), hunting, and mothers being killed so babies can be sold for pets.
Canon EOS 40D
Canon EF 70-300mm f/4-5.6 IS USM