At least 15 endangered Sumatran elephants have been shot or poisoned to death with cyanide-laced fruit this year, marking a sharp rise in the rate of killing from 2008, a government conservationist said Wednesday. The giant mammals were mostly killed by poachers for their ivory, said Tony Suhartono, the director of biodiversity conservation at the Forest Ministry. The number killed in the past six months is equal to the total for the whole of 2008, he said. It is shocking,'' said Syamsidar, a campaigner with the World Wildlife Fund in the western island of Sumatra. The killing is the result of a conflict between humans and elephants,'' said Syamsidar, who like many Indonesians goes by a single name. The forest is in critical condition due to the illegal logging, slash-and-burn farming practices and plantations.'' Indonesia's endangered elephants, tigers, rhinos and orangutans are increasingly threatened by their shrinking habitat in the jungle, which is commonly cleared for commercial farming or felled for lumber. Only 3,000 Sumatran elephants are believed to remain in the wild. They sometimes venture into inhabited areas searching for food and destroy crops or attack humans, making them unpopular with locals.