A male one-horned rhinoceros has been shot by poachers at World Heritage Site, Chitwan National Park, in Nepal. The rare species had its horn and tail taken out by its killers while leaving the animal a bullet on its head.

The Telegraph reported Chief Warden Ram Chandra as saying that the poachers made its operation during a storm. "It appears that they were planning this for a long time and were waiting for an opportunity to strike," he told reporters. Officials of the Chitwan National Park believed that the poachers used a silencer because there were no gunshots heard by a nearby village.

It's been three years since the last killing of the rhino at the park after the country integrated its anti-poaching procedures. Meanwhile, environmentalists took a one-horned rhino earlier in April in an attempt to populate the park with the species.

Officials released five rhinos in the western region of the park only recently so they can breed more. According to Sky News, Nepal is home to 645 rhinos and is commended for its conservation program which doubled the rhino's population in a few years.

Rhinos are now critically endangered and are believed to be lower than 30,000 in numbers. The one-horned rhino is believed to be only 3,500 left in the wild, while other Asian species like the Sumatran rhino runs in 100 and the Javan rhino with about 61 that's left of them. In Africa, there's only 19,666 to 21,085 left of the white rhinos and 5,040 to 5,458 of the black species, in a statistic count by world organization, Save the Rhinos.

The one-horned rhino has been greatly poached in Asia for its medicinal properties against fever and pain. During the 19th century, the greater one-horned rhinos were almost extinct if not for conservation programs being pushed by the countries.