Acoustic Analysis of Mallee Whipbird Calls

The Mallee Whipbird is an Endangered subspecies of the White-bellied Whipbird, endemic to south-eastern South Australia. At present, little is known about the current distribution and population size of Mallee Whipbirds due to their scarcity and cryptic nature. To ensure their persistence, we need to determine the current population status of the Mallee Whipbird.
One emerging tool that may overcome past obstacles to Whipbird population surveys is the autonomous acoustic recording unit (ARU). Mallee Whipbirds have a distinctive and far-reaching call. ARUs can be deployed across suitable Whipbird habitat and if a bird is present its call will be recorded by any nearby units. This method allows an observer to simultaneously survey a huge area, vastly increasing survey efficiency. An added advantage is that ARUs monitor passively and will cause relatively little disturbance to wildlife. ARUs have already been deployed on a small scale to successfully determine the presence of Whipbirds in some habitat patches. However, a network of ARUs will quickly produce hundreds of hours of field recordings and analyses of such large datasets would not be possible without specialist software to aid in identifying targeted calls. The development of a call template or ‘recogniser’ is a nuanced but necessary step in automating call detection. Subtle variations in frequency or duration may cause vocalisations to go undetected so it is important that any recogniser is comprehensively proofed against field recordings with known target calls. The call of the Mallee Whipbird is complex, containing multiple disparate phrases and sometimes subtly alternating pitch and intensity across an extended vocalisation. These factors will make it more difficult to identify candidate phrases for a call recogniser.