Wildlife Crime and Monitoring: Applications for Ranger-Collected Data

Anthropogenic factors such as habitat loss, over-harvesting and the introduction of non-native species are causing declines in global biodiversity. In sub-Saharan Africa, illegal hunting for bushmeat or high-value products such as rhino horn and ivory is threatening many mammal populations. Monitoring these populations is vital to ensuring their survival, yet professional scientific monitoring programs are costly and logistically difficult. Ranger-based monitoring, where rangers record evidence of illegal activities or wildlife sightings when on patrol is becoming increasingly popular.
Here, we use maps of occurrence probability of bushmeat poaching derived from ranger-collected data in Queen Elizabeth National Park (QENP), Uganda, to determine the direct impacts of illegal hunting on herbivore populations. We found that the main target species for bushmeat poaching, Uganda kob, showed declines in areas predicted to have high poaching risk, reporting population level impacts of illegal hunting in a savannah for the first time.
We go on to document how ranger-collected elephant sightings data can be used to predict their spatial distribution within QENP, using Bayesian hierarchical occupancy modelling to address the non-systematic method of data collection. We also attempt to create a time series model of elephant abundance in order to predict rapid declines that can occur in elephant populations.
We conclude by highlighting the potential for ranger-based monitoring and ranger-collected data, suggesting ways it might be incorporated to continually monitor vulnerable populations in light of a rapidly expanding human population.