Evaluating the efficacy of an integrated law enforcement approach to safeguarding Sumatran tigers and their prey.

Protected areas face immense pressure for their resources and the space that they occupy. To protect them and their wildlife, management approaches such as ranger patrols and measures to counter wildlife trafficking across the broader landscape have been implemented, despite integration of both approaches remains limited. This study aimed to evaluate such implementation in one of Asia's most significant protected area landscapes. This was done by analysing 1) an adaptive ranger patrolling strategy to reduce tiger (Panthera tigris) and ungulate prey poaching rates; 2) a government-civil society partnership to reduce tiger trafficking in adjoining rural and urban areas; and 3) tiger and prey population trends in response to these interventions. From 2015 to 2019, five ranger teams conducted 457 anti-poaching foot patrols, covering 10,963 km and removing 780 snares commonly encountered in accessible lowland. Over the years, snare occupancy did not change but detection was found to increase. From 2010 to 2019, law enforcement responded to 26 tiger trafficking cases with earlier cases mainly prosecuted using administrative sanctions. After 2013, most received penal sanctions with significant increases in fines levied. Camera trapping from 2010 to 2020 revealed a likely stable tiger population with high turnover of individual tigers. Only one male captured on all three sampling occasions and one adult female captured on two occasions. From 2010 to 2020, three tiger prey species (muntjac (Muntiacus muntjak), serow (Capricornis sumatraensis), and pig-tailed macaque (Macaca nemestrina)) remained widespread during the study, whereas wild boar (Sus scrofa) and sambar deer (Rusa unicolor) remain localised. Despite effective snare removals and arrests, the threat of poaching persists, suggesting that patrolling in at-risk areas needs to be coupled with new, persuasive, and more targeted approaches, while ensuring sustainable funding for these interventions.