The world's gorilla population is in both better -- and worse -- shape than what many believe, according to a UC Davis biological anthropologist who has studied gorillas for 25 years. Using updated criteria developed by the think tank International Union for the Conservation of Nature, A.H. Harcourt reassessed the gorilla's conservation status, and calculates that more than 100,000 gorillas exist in Africa, essentially doubling previous estimates. His result is based on findings that gorillas live in higher densities and in more habitats than previously thought, including swamp forests. But the outlook for gorillas' survival over the next century is bleak, Harcourt says. Increasing human density and expected increased logging of African forests will reduce greatly gorilla habitat, forcing a crash in gorilla numbers. "We can predict now that the gorilla, its subspecies, and its remaining populations will all fall to 'endangered' status some time in the next century, maybe half century," Harcourt says. Ultimately, the only gorillas in Africa will be those in national parks, where their numbers should stabilize if the parks are protected. Harcourt's conclusions were published recently in the British journal Biological Conservation.