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Gobi Bat Project and Acoustic Detection of Bats Cori Lausen Birchdale Ecological Ltd. www.batsRus.ca.

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Presentation on theme: "Gobi Bat Project and Acoustic Detection of Bats Cori Lausen Birchdale Ecological Ltd. www.batsRus.ca."— Presentation transcript:

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: 1.To determine what species of bats are in the GGSPA using mistnets and bat detectors. 2.To record echolocation (bat ultrasound) from each species to know what each bat sounds like for identification without mistnet capture. 3.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 Wildlife Acoustics SM2BAT Titley Scientific Anabat Full spectrum Zero- crossing

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 Vespertilio murinus Eptesicus gobiensis MINIMUM FREQUENCIES OF PULSES Hypsugo alashanicus Myotis mystacinus

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

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)

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

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

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

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

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

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

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

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

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

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 Little Brown in low clutter Northern Myotis (a bat that tends to stay in high clutter) Little Brown in high clutter

30 Mexican Freetail Bat Big Brown Bat Two species of different families Produced at different levels of clutter Variation within an individual is much greater than between families! Search-phase Continuum

31 Frequency (kHz) Time (s)

32 Feeding Buzz

33 Tadarida brasiliensis Eptesicus fuscus Two species of different families Produced at different levels of clutter Variation within an individual is much greater than between families! Search-phase Continuum 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


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