1. Gobi Bat Project and Acoustic Detection of Bats
Cori Lausen
Birchdale Ecological Ltd.

2. Great Gobi Strictly Protected Area Bat Project
Main Goals of Project:
To determine what species of bats are in the GGSPA using mistnets and bat detectors.
To record echolocation (bat ultrasound) from each species to know what each bat sounds like for identification without mistnet capture.
To teach Mongolian biologists about bat acoustics and how to use the bat detectors to learn more about bats in Mongolia.

3. Great Gobi Strictly Protected Area Bat Project May 2011
BAT DETECTORS: ANABAT and SM2BAT

4. Bat Detectors and Software Donated to Mongolia:
Titley Scientific (Australia) - Anabat
Wildlife Acoustics (USA) - SM2BAT
Joe Szewczak (USA) – Sonobat (analysis software)

5. Two Types of Detectors Full spectrum Zero-crossing Wildlife Acoustics
SM2BAT
Full spectrum
Zero-crossing
Titley Scientific
Anabat

6. Species of bats captured in Gobi
Vespertilio murinus

7. Species of bats captured in Gobi
Eptesicus gobiensis

8. Species of bats captured in Gobi
Hypsugo alashanicus

9. Species of bats captured in Gobi
Myotis mystacinus

10. Species Differences at a Glance
Myotis mystacinus
Hypsugo alashanicus
Eptesicus gobiensis
Vespertilio murinus
MINIMUM FREQUENCIES OF PULSES

11. Species Previously Known from Great Gobi Strictly Protected Area Recorded but not captured May 2011
Photo: Ariunbold
Plecotus kozlovi

12. Water as a Limiting Factor
Studies in the Southwest USA (Rick Adams) have shown that bats do not move when their water source dries out, they just stop reproducing each year.
This means we need to keep checking for reproduction in dry areas with ephemeral water.
Enhancing Gobi’s water sources would be good for bats… it is currently being considered for bears (e.g. at Baran Tooroi).

13. Khulan Holes -keeping water open for bats

14. Making Bat-Friendly Water Troughs
A way for them to crawl out of water (or they will drown)
Appropriate size for all species of bats to benefit

15. Understanding bat echolocation
We can’t hear bats.
Frequency of sound: Humans hear <20kHz Speech is <5 kHz Most bats echolocate >20kHz (ultrasound). We therefore need to transform ultrasound into a lower frequency using bat detectors.

16. Sound Sound is a wave. Sound bounces off of objects providing echoes.
Object must be larger than one wavelength to reflect sound.

17. Sound Sound is a wave. Sound bounces off of objects providing echoes.
Object must be larger than one wavelength to reflect sound.
A 35 kHz frequency has a wavelength of ~1 cm, and would therefore best detect this size of object.

18. Wave Length Wave length Increases as frequency decreases
35kHz wave length = 10 mm
70kHz wave length = 5 mm
Shorter wavelengths (Higher Frequencies)
Can detect smaller objects
Provide finer detail
Longer wavelengths (Lower Frequencies)
Travel further (Less absorbed by the air)
Objects have to be larger or about the same size as a wave length to be detecter
Shorter wave lengths/higher frequencies provide more detail and can detect finer texture
So why wouldn’t all bats use really short wavelengths (high frequencies)?
Higher frequencies travel less distance because of Atmospheric Attenuation
So there is a battle for bats to produce the optimal calls to detect their environment and their prey items. 18

19. Example of ultrasound from Gobi Bats….
35 kHz allows bat to detect objects 1 cm.
Frequency (kHz)
Time (s)

20. Frequency (kHz) Time (s) Properties of bat echolocation.
The effect of CLUTTER.
Frequency (kHz)
Time (s)

21. Frequency (kHz) Time (s) Properties of bat echolocation.
The effect of CLUTTER.
Frequency (kHz)
Time (s)

22. Frequency (kHz) Time (s) Properties of bat echolocation.
The effect of CLUTTER.
Frequency (kHz)
Time (s)

23. Frequency (kHz) Time (s) Properties of bat echolocation.
Clutter:
-trees
-grass
-ground
-other bats
-detector
-insect prey
etc.
Properties of bat echolocation.
The effect of CLUTTER.
Frequency (kHz)
Time (s)

24. Frequency (kHz) Time (s) Properties of bat echolocation.
Clutter:
-trees
-grass
-ground
-other bats
-detector
-insect prey
etc.
Properties of bat echolocation.
The effect of CLUTTER.
Frequency (kHz)
Time (s)

25. Frequency (kHz) Time (s) Properties of bat echolocation.
Clutter:
-trees
-grass
-ground
-other bats
-detector
-insect prey
etc.
Properties of bat echolocation.
The effect of CLUTTER.
Frequency (kHz)
Time (s)

26. Frequency (kHz) Time (s) Properties of bat echolocation.
Clutter:
-trees
-grass
-ground
-other bats
-detector
-insect prey
etc.
Properties of bat echolocation.
The effect of CLUTTER.
Frequency (kHz)
Time (s)

27. Frequency (kHz) Time (s) Properties of bat echolocation.
Clutter:
-trees
-grass
-ground
-other bats
-detector
-insect prey
etc.
Properties of bat echolocation.
The effect of CLUTTER.
Frequency (kHz)
Time (s)

28. In High Clutter: Species/genera/families often converge High slope
Short duration
Long frequency sweeps
Raised frequency

29. Clutter … makes identification of some species challenging
Northern Myotis
(a bat that tends to stay in high clutter)
Little Brown in low clutter
Little Brown in high clutter

30. Search-phase Continuum Two species of different families
Produced at different levels of clutter
Variation within an individual is much greater than between families!
Big Brown Bat
Different voices… CLUTTER!!!! Introduce topic here
Mexican Freetail Bat

31. Frequency (kHz)
Time (s)

32. Feeding Buzz
Short, steep pulses give better distance resolution because they are more sharply defined in time
Long flat pulses can detect objects from further away
Flat calls can also be used to measure relative velocity between the bat and the prey item (ie. horse shoe bats)

33. Search-phase Continuum
Eptesicus fuscus
Two species of different families
Produced at different levels of clutter
Variation within an individual is much greater than between families!
Different voices… CLUTTER!!!! Introduce topic here
Tadarida brasiliensis
SLIDE BY C. CORBEN, ANABAT WORKSHOPS

34. To Understand Species Diversity in Mongolia
Collect reference calls from captured bats
-bat distributions can then be determined using bat detectors
-capture may not be required in many places of the country if a good reference call collection is established
-to evaluate whether taxonomic classifications are accurate, recording ultrasound from potentially cryptic species is important (e.g. Soprano vs Commom Pipistrelles in Europe)

35. Obtaining Reference Calls from Captures
Hand-released *
Zip-lining
Bat-kiting
*Try to obtain ‘free-flying’ calls so wait until the bat has flown out of the hand but is still within recording distance of microphone. Ideal if they circle back over you, or you can run after them!

36. Reference Calls from Bats Tethering Techniques
Zip-line
Bat-kite

37. Effects of Releasing a Bat

38. Analook View Unknown and Reference Files

39. Sonobat View Unknown and Reference Files