Ultrasound use by Sunda colugos offers new insights into the communication of these cryptic mammals

Abstract

Recent reports of the use of ultrasound for communication by nocturnal mammals have expanded our understanding of behaviour in these animals. The vocal repertoire of colugos has so far only been known to include audible sound. Here, we report the use of ultrasound calls by Sunda colugos (Galeopterus variegatus, order Dermoptera). We recorded one type of call emitted by seven individuals with mean individual frequencies between 37.4 ± 0.6 and 39.2 ± 0.7 kHz during its maximum energy and lasting 28.7 ± 1.6 to 46.9 ± 21.1 ms. Each call showed 3–36 sequential pulses with individual mean interpulse intervals between 423.0 ± 101.4 and 1230.0 ± 315.4 ms. High frequency calls may serve as cryptic anti-predator alarm calls. Our observations suggest that more species of nocturnal mammals may use ultrasound to communicate, and that further studies are needed to determine the occurrence, function and diversity of these calls.

Keywords:

• Dermoptera
• Malaysia
• Primatomorpha
• Galeopterus variegatus

Acknowledgements

We thank the Forestry Department Peninsular Malaysia, The Habitat Penang Hill and Penang Botanic Gardens for permitting access to the study sites. We also thank the Department of Wildlife and National Parks Peninsular Malaysia for research permits for this study that was part of the Penang Hill BioBlitz 2017. Special thanks to Susan Lappan for proofreading and valuable comments on the manuscript, and to Bud Chapman and Foo Kai Xin for their assistance during night sampling.