Orangutan killing and trade in Indonesia: Wildlife crime, enforcement, and deterrence patterns

Wildlife poaching and illegal trade threaten the survival of many rare species. We assessed spatiotemporal patterns in illegal killing, injury, capture, possession, and sale of orangutans, as well as law enforcement efforts, and conservation interventions affecting Critically Endangered orangutans in Indonesia from 2007 to 2019 using data collected from published and unpublished sources. We found 2229 reported crimes during the study period, including killing and non-lethal crimes. Annual crime rates did not show a declining trend overall during the study period. Most crimes, 99.6 % for Bornean orangutans (Pongo pygmaeus), and 95.7 % for Sumatran (P. abelii) and Tapanuli (P. tapanuliensis) orangutans combined, involved local not international trade. A total of 22 court cases (0.9 %) related to 2229 reported crimes; 20 of these cases led to convictions. At expected detection rates of less than 10 %, average estimated species mortality from killing was 14.3 % for Tapanuli and Sumatran orangutans combined, and 5.1 % for Bornean orangutans. This exceeds the 1-2 % orangutan hunting mortality threshold expected to drive populations to extinction. National parks with orangutans had 0.28-2.11 enforce-ment officers per 100 km2, below the 3-11 officers per 100 km2 considered global best practice to deter poaching. The most prevalent interventions to address orangutan crime-education and handovers of illegally held animals-have been conducted without an associated decline in crimes. These tactics alone are insufficient to address orangutan-related crimes. Substantial increases in patrols, investigations, arrests, and convictions, as well as community-focused solutions are urgently needed to halt orangutan killing and trade.