Using playbacks to monitor and investigate the behaviour of wild maned wolves

Maned wolves are difficult to observe in the wild because of their low densities and their cryptic and crepuscular-nocturnal habits. Exploring their long-range acoustic communication may offer an efficient alternative to study the species. Here we evaluated the applicability of playbacks to study maned wolves in the wild and compare the results with 20 nights of passive recordings on the same area and month during the previous year. We obtained vocal responses on 3 of 6 nights tested, including responses involving two animals and an approach after an interactive playback. Although we conducted 3–6 playback sessions each day at different times, we only obtained vocal responses during sessions between 17:00 and 19:40. During our passive recordings we detected on average 0.86 roar-bark sequences per recorder per night, mostly during the first half of the night. Vocal activity – responses and spontaneous roar-bark sequences – during playback nights was nearly 4 times greater than during the passive recordings. We conclude that playbacks stimulate maned wolves to emit roar-barks and that this method is applicable to test hypotheses about maned wolf behaviour and aid in their monitoring.