Sharing his insights into on-the-ground conservation, Maarten Hofman (University of Goettingen, Germany & Bangor University, UK) discusses Moore et al.’s recent article, Are ranger patrols effective in reducing poaching-related threats within protected areas, and the wider implications for tackling illegal poaching.

Rangers are the heavy duty machinery in every protected area management’s human resource arsenal. Their list of duties ranges from public outreach and environmental education, over biodiversity monitoring to patrolling and law enforcement. Every day, countless rangers across the world put their lives on the line to protect wildlife and the natural environment. Over 1,000 rangers died in the line of duty during the last decade. Often working in challenging environmental conditions, under-equipped, with low pay and little recognition, they are collecting large amounts of invaluable data on the state of our planet, and provide the striking force for actively controlling the threats that endanger the wildlife and natural habitat on it.

One of the major threats to the world’s wildlife is poaching. Poaching is the illegal harvest or killing of wildlife to supply the demand for bushmeat, pets, and illegal wildlife products, or to retaliate for livestock or crop damage. With natural areas increasingly being fragmented by road networks, the risk of conflict between human and wildlife increases, and more and more wildlife populations are being opened up for exploitation. Globally, poaching pressure is so high that even captive animals are not safe, as was shown by the white rhinoceros that was poached for its horn this year in the Thoiry Zoological Park in France. Out in the field, rangers spend the majority of their time patrolling protected areas to detect and record illegal incursions and signs of poaching. Often they intervene, and poachers are intercepted and subsequently sentenced.

A case study in the Nyungwe National Park in Rwanda backs up the important role that rangers play. Jennifer Moore and colleagues show that the mere presence of rangers in the protected area can be sufficient to keep poachers at bay. They found that, as expected, poaching activities in the park increased with proximity to roads and paths through the area, but the increased density of patrols around ranger posts reduced poaching in their surroundings. The probability for poaching threats to occur decreased by 20 percent when the visit frequency of a site was cranked up from 0 to 20 visits per year, and by more than 50 percent for 50 visits per year. The presence of ranger posts and frequently patrolled areas around them even provided enough of an incentive for the poachers to move further into the interior of the park rather than sticking around the edges. This led to the unexpected observation that poaching levels were higher in the interior of the park than at the border, where most ranger posts are located.

The logical conclusion is: ranger presence needs to be intensified and patrol density increased to control poaching threats throughout the protected area, rather than just along the boundaries. However, resources for conservation are very scarce, and continuous coverage of large areas is impossible. Especially for species under severe pressure, finding sufficient resources to match those of large-scale organised poaching is challenging. For example, Barichievy and colleagues observed that high patrol density and ranger presence in a leading rhino conservation area in South Africa did not seem to lower the poaching rate. They suggested that the currently employed resources were insufficient to effectively deter rhino poachers. Other studies, too, found that the effectiveness of ranger patrols depends on the spatio-temporal density of patrols, and hence the number of rangers available, but that it is limited by the scarcity of resources for conservation .

So how can we maximise cost efficiency? How intense should ranger presence be? And where to focus efforts? In the Rwandan case study, the authors used dynamic occupancy models to find out why poaching threats occur where they do, and subsequently used the obtained results to predict where additional ranger posts and patrols would have the highest impact. Dynamic occupancy models require several observations per sampling site. That is, patrol routes need to be visited with some regularity and threats need to be logged with the same efficiency every visit. The models offer the advantage that they can distinguish whether observed increases in threats are due to an actual incremented threat level or simply because the patrolling and recording of threats was more efficient. They can do this because the repeated sampling allows for estimating the probability that a threat is actually detected, given it is present on the site. Clearly, this is a very valuable approach for predicting where ranger presence can make the biggest difference, enabling cost effective management of protected areas. The fact that such predictions can only be achieved using data collected consistently over several years emphasizes the role that rangers play in curbing illegal activities. Besides their presence, the recording of incursions over long time spans allows for adaptive management of the protected area. Tools such as the Spatial Monitoring and Reporting Tool (SMART) were designed to plan patrol routes and provide a database for archiving, managing, and analysing the recorded threats.

However, ranger presence is not a stand-alone solution. For example, when poachers are intercepted, persecution does not always follow. In some cases, local systems let poachers go without being held responsible for their illegal activities. Needless to say, this is extremely demotivating for passion-driven ranger teams that are risking their lives only to see the perpetrator the following day conducting his/her daily business in the village next door. Hence, other efforts are needed to effectively reduce poaching threats. Tackling corruption is one possibility; another is to remove poaching incentives, e.g. by reducing poverty and social inequality in surrounding areas or by reducing demand for the poaching products. All of these require local and regional political will and action… probably one of the biggest stumbling blocks along the road. Nevertheless, major progress was recently made towards reducing large-scale organised poaching: for example, the ban on ivory sales in China by the end of 2017, and the destruction of wildlife parts in Sri Lanka and Nepal. Some countries have managed to eliminate poaching almost completely (e.g. Nepal).

For the general public, one way to help is to report suspected illegal wildlife trade, e.g. through the Reporting Illegal Wildlife Trade initiative by WWF.

Jennifer Moore and colleagues’ article, Are ranger patrols effective in reducing poaching-related threats within protected areas is available in Journal of Applied Ecology.