Monitoring carnivores can be tricky. Lion, hyena, leopard, jackals and many of the smaller carnivores are mainly active at night, which means gauging their population sizes, movements and patterns can’t be done accurately by human monitors in the field.
In 2014 we started using motion-triggered camera units to help address this challenge. Their infrared heat motion sensor activates the camera whenever a warm body passes by, and with their wildlife-friendly flash system they have no difficulty capturing images at night. These cameras are in operation 24/7 for weeks on end without needing a battery recharge.
For our ecological monitoring team, understanding the density, number and occupancy of carnivores in the Conservancy is critical in ensuring we maintain a balance. Too many, and competition for food and territory has damaging consequences, and the risk of human/carnivore conflict in surrounding settlements increases. Too few, and this disrupts the rest of the food chain.
The team now has 144 trap points in 72 stations around the Conservancy. By placing two cameras facing each other, both sides of the same animals can be captured and the ecological monitoring team can accurately identify individual animals (important for getting accurate population estimates and territory intel).
In the lab, the photos are processed and using a Microsoft Access database dedicated to image processing. They are further sorted and filtered in Microsoft Excel where independent photo events are pulled out at 30 second intervals. This helps to determine the relative abundance index (RAI) of each species, which is the number of independent photo events of a given species in 100 ‘trap days’ divided by total camera trap days of that research period.
Relative abundance indices are not population estimates, but rather reflect the probability of encountering any given species within 100 days - which is how an animal would be classified as rare or common in a given habitat.
At the time of this initial studyin 2014, it was discovered that lions, jackals and hyenas had definitely reached their threshold within the Conservancy, which explained the frequent lion attacks on rhinos and hyena breaking into community livestock pens. Armed with this data, the Ol Pejeta wildlife teams can work with authorities and communities to take action. In one case in 2017, we moved a group of male lions that had developed a habit of attacking rhinos down to Tsavo National Park in south Kenya in order to protect the rhino population.