Our PostDoc Kevin Darras led an international research team to developed a new method: bat point counts. We combined modern sensing technologies – thermal, ultrasonic and near-infrared – to detect, identify and count all bats flying around in a certain range, with minimal taxonomical bias.
Bat point counts were conducted in oil palm plantations in Sumatra, Indonesia, to compare them against the established mist netting and ultrasound recording methods: we captured and measured 83 bats, analysed dozens of hours of recordings, and dissected hundreds of near-infrared pictures paired with hours of sound recordings. Even though bat point counts were only conducted for a third of the sampling time of the other methods, they succeeded in finding similar species numbers. We found that fruit-eating bats are rare in oil palm plantations, in stark contrast to previous studies, which used nets and had led researchers to believe that these bats dominated oil palm plantations. This new non-invasive method allows us to better understand bat behaviour and populations, which should lead to better informed conservation science and functional ecology insights.
You can find the full paper here: https://onlinelibrary.wiley.com/doi/10.1002/ece3.8356