Sloth bears population now stands at less than 20,000 New Delhi – AFP The populations of four vulnerable bear species have fallen by at least 30 percent in the last 30 years due to rampant deforestation, mining and poaching, a conservation group said on Monday. The Asiatic black bear, sloth bear, sun bear and Andean bear have suffered a 30-49 percent decline and are expected to plunge further, a biologist from the IUCN-SSC Bear Specialist Group (BSG) said at a conference in New Delhi. \"These four species are declining in most places where they live. The reasons include a decrease in habitat, poaching for bear parts and human retribution over damaged crops,\" Dave Garshelis, co-chair of BSG, told AFP. The population of sloth bears, which are native to South Asia, now stands at less than 20,000, and has entirely vanished from Bangladesh where the species used to roam freely. \"In India, mining and breaking up land to build roads has done a lot to destroy the habitat of sloth bears who cannot move to highland areas,\" Garshelis said. The Asiatic bear population has also plummeted, due to excessive poaching to meet the surging demand for the bile found in the bear\'s gall bladder, an ingredient used in Chinese traditional medicine. \"In China, bear numbers have fallen because of the illegal trade in bear parts to satisfy the Chinese market,\" Garshelis said. The five-day conference, which began on Monday, will see experts from 35 countries present research papers and reports on bear populations around the world.