New research finds that 500 years of over-exploitation has halved mammal populations in South America's once majestic Atlantic Forest. A new analysis of mammal populations reveals the devastating effects of human disturbance since the area was first colonised in the 1500s. Human activity is largely responsible for this overwhelming biodiversity loss according to the study. Originally covering around 1.1 million square km, the Atlantic Forest lies mostly along the coast of Brazil and is the world's longest continuous latitudinal stretch of tropical forest. Activities such as farming and logging -- as well as fires -- have reduced the Forest to about 0.143 million square km which has, in turn, had a significant impact on mammalian populations.