GUIYANG, Sept. 7 -- Five people have been sentenced to prison terms ranging from two to 16 years for poaching, trafficking and selling black leaf monkeys, an endangered species, in southwest China's Guizhou Province, local authorities said Monday.

The sentences were handed down in mid-August by the People's Court of Shuicheng County in the city of Liupanshui, where serial cases of poaching and selling the rare monkeys were uncovered, said the Guizhou Provincial Forest Public Security Bureau.

The court found that from 2011 to 2013, two poachers surnamed Zhao and Yang captured 5 black leaf monkeys in Xinqian Village, Shuicheng County and sold them via two traffickers to a man surnamed Yin, the former director of the Liupanshui zoo.

Yin also illegally transported a black leaf monkey from the zoo in Zunyi City to the Liupanshui zoo in October 2012.

The five were convicted of poaching, selling and trafficking endangered wild animals, the court said.

Three prime culprits, Zhao, Yin and Yang, were sentenced to 16, 11 and ten years in jail and fined 150,000 yuan (23,565 U.S. dollars), 100,000 yuan and 50,000 yuan respectively, it said.

The two traffickers, identified as Liu and Lu, were both sentenced to two years in jail and fined 10,000 yuan each, according to the court.

Black leaf monkeys mainly live in Guizhou Province, Guangxi Zhuang Autonomous Region and Chongqing Municipality in China and northern Vietnam.

The world population of black leaf monkeys is believed to be around 1,000, and the animals are under China's top-level protection, said Ran Jingcheng, director of the Guizhou provincial wild animal and plant management bureau. The International Union for Conservation of Nature listed the species on its Red List of Threatened Species in 2012.