 Humans have been hunting mammals in Asia for at least 40 @,@ 000 years , but until recently , slow lorises were only hunted at a sustainable level . However , hunting pressure since the 1960s has become increasingly unsustainable , leading to overexploitation , because of growing demand , decreased supply , and the subsequent increased value of the marketed wildlife . In 1985 , large wildlife markets began to appear in Phnom Penh and Sen <unk> , Cambodia , followed quickly by the development of networks of hunters , traders , and middlemen . Bright flashlights make spotting slow lorises much easier at night because of their eye shine , and in the 1990s , large @-@ scale commercial harvesting of slow lorises began as improved batteries for spotlights became available . 
