Most tigers in Sumatra are killed deliberately for commercial gain. According to a survey from TRAFFIC, the global wildlife trade monitoring network, poaching for trade is responsible for over 78% of estimated Sumatran tiger deaths—amounting to at least 40 animals per year. Despite intensified conservation and protection measures in Sumatra and the apparent global success in curtailing markets for tiger bone, there is no evidence that tiger poaching has declined significantly on the island since the early 1990s and now palm oil deforestation is worsening the situation.
Source: WWF