[en] In the vast protected areas of Africa, traditional wildlife surveys performed by plane or foot are logistically difficult to implement due to the lack of means and appropriate materials. Moreover, the possibilities of encountering poachers in the field pose a serious risk to the monitoring teams.
Over the last decade, civilian UAS (Unmanned Aerial Systems) boomed in natural resource monitoring. One of the biggest challenges of the UAS is to replace traditional wildlife censuses for the application of wildlife conservation. Parameters have to be approached in a different way than before.
We performed test flights in the open savannah of the Garamba National Park during the wet season using the Falcon Unmanned UAS. Both photos (Sony Nex7, 24Mp) and videos, including thermal infrared videos (Tamarisk 640x480), have been used. Flight altitude ranged from 50 to 200m and pictures showed that animals can be effectively detected at 100m. We spotted elephants, hippopotamus and buffaloes as well as other smaller species such as hartebeests, kobs and warthogs. Thermal videos gave medium quality results during the day due to the heat but performed well during the night. The limited range and endurance of the UAS suggest a rethink of the usual census protocols. We therefore tested new flight plans in a rosette shape to take advantage of the higher points in the park, with transects having the length of the maximal range. Twelve transects of 10km can be covered in half a day with pictures covering a 15.6km² area. Human activities could also be detected. Pictures showed areas burned by poachers and the thermal infrared camera allows the detection of fires from a high altitude.
Future developments need to be investigated such as automatic detection to review the huge amount of data collected and statistical methods must be adapted to those challenging situations.
