Behavioural responses of white rhinoceros to species-specific playbacks

Translocated white rhinoceros (Ceratotherium simum simum) sometimes disperse out of protected areas and must be transported back by truck. Drones and siren sounds can frighten rhinos away from dangerous areas and could be used to avoid stressful re-capture and transport, but these stimuli also affect other species. Therefore, we tested whether playbacks of species-specific rhino calls can influence rhino movements and could potentially be used as a less invasive management tool. We played different call types (contact “pant” calls, threat calls and whines from calves) as well as a control (bird calls) back to 20 free-roaming white rhinos in two different reserves in Botswana. We expected that rhinos would approach the loudspeaker when “pants” and “whines” were played back and move away from “threats”. Calls for playback stimuli were levelled to a volume of 85 dB and played back to focal rhinos from distances between 10 and 100 m. Preliminary results show that rhino responses to playbacks included alertness, vocalising, approaching the loudspeaker and running away. Responses were not consistent per call type but seemed to depend on sex of sender and receiver and on the behaviour of the tested rhino before the playback. In most cases, rhinos returned to their previous behaviour within 5 minutes after the playback. We are planning further experiments to test whether multiple repetitions of playbacks lead to different results. However, short playbacks might already be used to facilitate the identification of rhinos for monitoring personnel in large reserves with many rhinos, as most rhinos reacted by turning towards the loudspeaker and pointing their ears forwards, enabling visualisation of identifying notches.