EDITOR'S CHOICE: Safeguarding Sumatran tigers: evaluating effectiveness of law enforcement patrols and local informant networks

Abstract

Summary1. The United Nations recently listed illegal wildlife trade as a serious crime because of the escalating demand for highly prized species, such as tiger and rhinoceros, and the failure to effectively control the trade. In turn, this places greater urgency on reducing supply by securing source populations of these species. Yet, whether law enforcement strategies designed to mitigate poaching are succeeding remains poorly understood, despite the millions of dollars invested annually in this mainstay conservation strategy. 2. Here, we assess the performance of one of Asia's longest running law enforcement programmes, from Kerinci Seblat National Park in Sumatra, by investigating whether forest ranger patrols reduced the occurrence of snare traps set for tiger and its ungulate prey base; local informant reports on poaching influenced ranger patrol success; and the resulting population trends of target species changed in response to these conservation actions. 3. A total of 4433 snare traps were removed during 642 foot patrols conducted from 2000 to 2010. Controlling for the influence of varying detection probabilities, as well as accessibility and other possible determinants of illegal hunting, revealed that sites with a greater frequency of patrols, rather than the combined distance walked, had a lower occurrence of snare traps in succeeding years. 4. Patrols conducted on the basis of local informant 'tip-offs' were significantly more likely to detect snare traps than routine patrols, with reports increasing detections by over 40%. 5. There were no significant changes in the occupancy status of the tiger prey base from 2004 to 2011, suggesting that it remained stable during this period. The relatively good condition of prey and predator populations in Kerinci Seblat National Park was further supported by the results of an independent survey conducted in 2008-2009 which revealed a widespread tiger occurrence. 6. Synthesis and applications. Our results not only demonstrate the effectiveness of the Kerinci Seblat law enforcement strategy in protecting wildlife, but highlight the benefits from cultivating a network of reliable informants. The study also represents a critical step in helping these urgently needed conservation assessments to become common place in the fight to save flagship species.

Understanding complex drivers of wildlife crime to design effective conservation interventions

“…It also dispels the idea that law enforcement and community engagement are discrete choices, whose objectives are automatically opposed. This is supported by our finding that local reporting of illegal activities, an essential element of efforts to combat illegal trade in high‐value species (Linkie et al ; Cooney et al. ), was predicted to be increased through greater community engagement.…”

On the extinction of the single‐authored paper: The causes and consequences of increasingly collaborative applied ecological research

“…We are hopeful that at least some of the increase in the size of author lists reflects such changes, as many recent papers involve a mix of authors from a range of institutions, including research institutes, universities and regional government agencies (e.g. Carboneras et al., ; Giljohann et al., ; Linkie et al., ).…”

Are ranger patrols effective in reducing poaching‐related threats within protected areas?

“…number of ranger patrols and locations of ranger posts) and threat dynamics; such relationships permit predictions needed to inform management decisions. Data collected by rangers while on patrol have previously been used to assess illegal activities within protected areas in Uganda, Democratic Republic of Congo, Rwanda, Sumatra and India among others (Critchlow et al., ; Gray & Kalpers, ; Linkie et al., ; Mackenzie, Chapman, & Sengupta, ; Stokes, ). However, whether and to what extent ranger patrols reduce poaching‐related threats generally remains untested.…”

“…Thus, we also sought to (4) evaluate the efficacy of ranger patrols in reducing poaching‐related threats in NNP. We used dynamic occupancy models to analyse the data (MacKenzie et al., , ) because they provide a rigorous statistical framework for estimating relevant parameters while also accounting for imperfect detection of threats by rangers (Goswami et al., ; Linkie et al., ; MacKenzie et al., ; Sharma, Wright, Joseph, & Desai, ).…”