The expansion of commercial plantations in tropical countries at the expense of species-rich rainforests is causing a serious erosion of biodiversity. A systematic study of rainforests and converted land in countries growing oil palm shows that only a sixth of the species normally found in a region remains after forests have been felled to make way for cash crops. The review of the status of birds, bats, ants, and other species reported in Trends in Ecology and Evolution strengthens the consensus that plantations are a poor substitute for old-growth lowland tropical forests when it comes to species survival. The findings reported by scientists from the Zoological Society of London and the University of East Anglia should encourage countries in Central Africa, Latin America, and Southeast Asia that have rich species diversity, to stop further deforestation. Rainforests have long been recognised as globally important for the role they play as carbon sinks that help stabilise climate. It is extremely damaging to the environment, therefore, that these unique forests continue to be cleared in several countries, led by Malaysia and Indonesia, to produce