The population of West African chimpanzees in Cote d’Ivoire has declined 90 percent in the last 18 years, according to a new study published in Current Biology. In the 1960s, the West African country was home to about 100,000 of the apes; in 1989-1990, scientists counted 8,000 to 12,000, which they estimated to be half the remaining population of the species. The most recent count turned up 800 to 1,200 chimps. “We were not expecting such a drastic decrease,” says lead author Geneviève Campbell. Researchers attribute the chimp decline to a 50 percent jump in Côte d’Ivoire’s human population since 1990, as well as civil unrest that has been simmering since 2002. Hunting and deforestation have skyrocketed; one national park has lost a full 93 percent of its forest cover since 2002. And more bad news may be ahead: External funding for Taï National Park, where chimpanzees are holding strong, is scheduled to end in 2010.