1. Night Parrot: A sound approach
By Mark Carter

2. Mark Carter Zoologist with Outback Ecology: MWH
Lifelong birder- lifelist over 2000.
NT-based (Alice Springs)
Background in Park Service and professional Bird Guiding

3. Night Parrot; the challenge
Seeking a cryptic rarity in a vast landscape
Low confidence in knowledge of habitat, lifecycle, distribution, status, vocalisations.
“Legend bird” status has drawbacks- tall tales, wishful thinking and the ‘Loch Ness Monster’ effect.
The grand race to be first to find it...

4. The Promise of Bioacoustics
Verified and accessible Night Parrot reference calls will be key to finding and understanding the species.
The sole successful example of targeted search for Night Parrot to date was reportedly through use of a recorded call in playback.
Acquisition of Night Parrot reference calls will enable automation of passive acoustic surveys.

5. Acoustic Methods: Aural Surveys
Common method for cryptic species in difficult habitats; jungle, wetland, mountain, nocturnal avifauna
“the vigil” approach
Suveyor knowledge of the target species’ vocalisations essential
timing is vital to avoid false negatives
opportunities for visual confirmation of species
subjective- unless simultaneous recordings made

6. Acoustic Methods: ARUs
Autonomous Recording Units
Long-duration autonomous deployments
Technology improving quickly. New units are more capable, accessible and cheaper.
Used increasingly in field research worldwide
Huge savings in man-hours and/or survey coverage over ‘manual’ techniques
Huge data sets

7. An example acoustic survey: Cloudbreak 2013
FMG Cloudbreak Expansion Project: Pre-clearance Night Parrot Survey. Feb 2013
4 SM2 ARUs
36 ARU Nights at 17 locations
c.360hrs acoustic data
16 Aural Surveys performed
c.20 hrs of listening (and recording)

8. Survey Sites

9. Typical site

10. Site selection
Habitat information drawn from past work by Dr.s M. Bamford and S. Murphy
Targeted spinifex/bluebush/samphire mosaics
Long unburnt spinifex
Geographic spread
Representative of study area

11. ARU Configuration Sunset to sunrise recording WAV format 48dB gain
44kHz sample rate (captures c.20khz and below)
HPF 180kHz (1000kHz near active mine)
mounted c.75cm above ground level
internal power

12. ARU deployments

13. Aural Surveys ‘Vigils’
2 birders simultaneously listening- full species list every 15 minute interval.
Time and description of anomalous sounds recorded.
Field recorder (Tripod mounted Zoom H2n,stereo soundscape recording) running whole time.
Surveys very useful in ‘calibrating’ ARU analysis

14. Aural Surveys

15. Acoustic data analysis
Automated analysis (Sound ID, Songscope) considered, but rejected.
Investment in configuration time is considerable
Current systems very good at finding known sounds but not designed for finding unknowns.
With Night Parrot reference calls these techniques will be powerful, but until then...

16. Manual Analysis Low risk of false negatives Low setup time and cost
Uncomplicated (comparatively)
Heavily reliant on knowledge of analyst

17. Manual Analysis (cont)
Raven lite by Cornell Lab of Ornithology Bioacoustics Research Program.
Spectrograms- Visual representations of sound
Sound analysed at 4-6x real-time
Sounds of interest listened to in real-time.
Analyst relies on own experience of ‘birding by ear’ and call reference libraries to detect genuine ‘unknowns’.
Species lists generated, but main focus is ‘unknowns’.

18. Manual Analysis (cont)

19. Rankings Unknown sounds ranked Internal peer review
External review if necessary
Rank
Criteria
High
Sound is comparable in frequency, power and/or timbre to calls of known parrot species.
Medium
Sound is comparable in frequency, power and/or timbre to calls of known bird species within the correct size range and could feasibly be produced by a parrot.
Low
Sound is comparable in frequency, power and/or timbre to calls of a known bird species but is probably unlikely to be made by a parrot.
Nil
Sound is not comparable in frequency, power and/or timbre to calls of known bird species and is unlikely to be made by a parrot.

20. Results ARUs recorded 41 species total Aural surveys 51 species total
18 “unknown” sounds
Rankings: 3 ‘medium’, 15 ‘low’ or ‘nil’
No ‘likely’ calls found

21. Conclusion
Acoustic techniques are powerful survey methods with advantages over other approaches.
Quantity of data is a challenge.
Analysis methods need refinement.
Reliance on skilled surveyors
Verified reference calls will allow analysis automation and confident IDs.

22. Thank You for listening
©Simon Mustoe