A detector-based bat survey in Aukštadvaris area (Lithuania) in August 2005

8th European Bat Detector WorkshopAukštadvaris, 18—21 August 2011

Matti Masing & Kazimieras Baranauskas

Contents

Summary

Team

Methods, equipment, weather

Study sites, maps

Results

Conclusions

Bat sounds from Aukštadvaris area, August 2005

Summary

During two long nights, 05/06 and 06/07 August 2005, bats were observed, counted and identified in Aukštadvaris Regional Park, Lithuania using a Pettersson D240 ultrasound detector.

17 sites belonging to four different areas were examined. Total time of counts was 141 min in line counting, and 345 min in point counting.

As a result, the following 11 bat species (forms) were proved: Myotis dasycneme, M. daubentonii, M. brandtii/mystacinus, Plecotus sp. (most probably, P. auritus), Barbastella barbastellus, Pipistrellus nathusii/livonicus, P. pipistrellus, P. pygmaeus, Eptesicus nilssonii, E. serotinus and Nyctalus noctula.

Additionally, up to 2 more species (Vespertilio murinus and Nyctalus leisleri, both calling on 24 kHz) might have occurred in the counts.

The sounds of both identified and unidentified bats are stored in an electronic database and can be examined for species identification in the future.

Team

Our team consisted of two boreal bat experts (authors of this presentation) while Yrjö Siivonen and Terhi Wermundsen joined us later when observations were carried out in other areas, Kauno Marios and Užtrakis (Fig. 1).

Our aim was to learn boreal bats – their habitats, habits and diagnostic sound characters of species'. The combination of a sensitive ultrasound detector and a powerful counting method gave us an opportunity to get the best possible results.

Fig. 1. Kazimieras Baranauskas, Yrjö Siivonen and Terhi Wermundsen preparing for a bat-night (all photos by Matti Masing).

Methods, 1

RCM-2 consists of two submethods: line counting (LC) and point counting (PC). The results of both submethods are treated separately (Masing et al., 2002, 2005; Keppart et al., 2005).

Counting lines and points were established in relatively good habitats, where bats were supposed to fly during the night (Fig. 2). These sites were put on the map.

In LC, walking speed was approximately 3 km/h. Bats were marked on a working map on every 50 m segment of the rout, which later allowed to transfer the counting data into monitoring indices.

In PC, the counting time was either 5 min at each point (in forests and elsewhere away from large bodies ow water) or 15-30 min on lake shores and on bridges over canals.

In PC, bats were counted per each minute of count, thus their flight activity could be measured. During the count, the results of PC were written down in a notebook.

NB! – When using RCM-2 no bat is missed from the count!

Fig. 2. Point counting point number 8, shore of a small lake.

Methods, 2

Bat-detector (Pettersson D240) was fixed on 35 kHz, the frequency on which most boreal bats can be heard, and many of them identified. For the identification of narrowband species (Eptesicus, Nyctalus, Pipistrellus, Vespertilio) the frequency on the display was temporarily changed to find the best listening frequency (BLF) of the passing bat.

To hear bats outside the 30-40 kHz range, a special method (so-called Vilnius-method) was used: the time-expansion button of D240 was pressed 2-4 times a minute after which time-expanded sounds were listened for 5 sec from one „ear“ of the earphone (at the same time the present-time heterodyne sound was heard from the second „ear“).

This enabled to hear all ultrasounds available in the area during regular 0.5 sec intervals. In such way Pipistrellus pygmaeus and other high-calling bats were easily heard.

Distant sounds of Vespertilio murinus and Nyctalus noctula were also heard using Vilnius-method, while most of them were not heard in heterodyne when the detector was tuned on 35 kHz.

Methods, 3

Bat species were identified partly on spot, using both heterodyne and time-expansion sound characters.

The two sonic forms of Pipistrellus nathusii s.l. (Pipistrellus nathusii s.str. and Pipistrellus livonicus; Masing, 2004, 2006) were separated to avoid confusion with Pipistrellus pipistrellus, which is a relatively common bat in Lithuania.

Sound samples were taken on a tape to study them later, and to identify more animals on the basis of their sounds.

The Pettersson BatSound program (version 3.31) was used to analyse bat sound samples.

Methods, 4

Abbreviations of species' names(one capital letter to mark a common sedentary boreal bat species)

E – Eptesicus nilssoniiM – Myotis daubentoniiP – Plecotus sp., probably auritus

bar – Barbastella barbastellusbm – Myotis brandtii or M. mystacinusdas – Myotis dasycneme

liv – Pipistrellus livonicus (the high-calling form of Pipistrellus nathusii s.l.)mur – Vespertilio murinusnath – Pipistrellus nathusii s.str. (the low-calling form of Pipistrellus nathusii s.l.)noc – Nyctalus noctula

pip – Pipistrellus pipistrelluspyg – Pipistrellus pygmaeusser – Eptesicus serotinus

sp24 – Chiroptera sp. calling on 24 kHz (probably Vespertilio murinus or Nyctalus leisleri)

Equipment(Panasonic RQ-L11 recorder, Pettersson D240x detector, Philips earphones)

Weather

The first night (05/06 August) was quiet and almost cloudy, air temperature about +14 °C, relative humidty from 85% (evening) to 92% (morning). Observations were carried out between 22.28 and 04.30 (local summertime).

The second night (06/07 August) was different. There was a rain in the evening, which stopped at 22.45. So the habitats were rather wet all night long. During the night it was quiet and cloudy, air temperature from +14 °C (evening) to +13 °C (morning), relative humidty slightly over 90% all night long. Observations were carried out between 22.51 and 05.25 (local summertime).

Study sites (maps 1—5)

During the first night (05/06 August) the following sites were studied: 1) relatively old mixed forest at Skrebio; 2) northern shore of Aukštadvario Lake; 3) western shore of Aukštadvario Lake; 4) bridge over a narrow canal, west of Aukštadvario Lake; 5) relatively old mixed forest at Pilaites, 6) southern shore of a Lake Antakmeniai near a bridge.

During the second night (06/07 August) the following sites were studied: 7) southeastern shore of Lake Moša, a beach by a large sporting camp; 8) western shore of a small lake, 300 m south of site 1; 9) a bridge between two lakes in Streva canyon; 10) shore of Lake Streva, a dam at northern end of the lake; 11) eastern shore of Lake Streva; 12) forest path by Lake Streva; 13) southern shore of Lake Streva; 14) western shore of Lake Spindžius, by a road bridge; 15) eastern shore of Lake Vilkokšnis at Tolkiškes, behind a campsite; 16) forest road by Lake Vilkokšnis at Tolkiškes; 17) forest path by Lake Spindžius.

As a result, 17 observation sites belonging to six areas were studied, those areas are referred to as follows: 1) Skrebio and Aukštadvaris, 2) Moša and Antakmeniai, 3) Pilaites, 4) Streva, 5) Spindžiaus, 6) Tolkiškes.

Map 1: study area(general map with main sites of study in August 2005)

Map 2: study sites 1—8(Skrebio, Aukštadvaris, Pilaites, Antakmeniai, Moša)

Map 3: study sites 9—13(Streva)

Map 4: study sites 14 and 17(Spindžiaus)

Map 5: study sites 15 and 16(Tolkiškes)

Results, 1(no detailed counting data here, species only)

Results of the first night (05/06 August)

Site number

Place, habitat Time (start of the count)

LC, duration(min)

PC, duration(min)

LC, bats found PC, bats found

1 Skrebio, forest 22.28 60 15 x 5 min = 75 E, M, liv, nath, noc, pyg, ser?

M, bar, nath, pyg, ser?

2 Aukštadvario Lake, N-shore

00.58 15 M, liv, nath, noc

3 Aukštadvario Lake, W-shore

01.26 2 x 15 min = 30 Msp, das?, nath, noc

4 Bridge, canal 01.45 2 x 15 min = 30 E, M, nath, noc

5 Pilaites, forest 02.12 28 6 x 5 min = 30 nath, ser bar, nath

6 Lake Antakmeniai, S-shore

04.13 15 nath, noc, pip, pyg

Total, proved(8 + 1 + 1? species)

88 195 E, M, liv, nath, noc, pyg, ser

E, M, das?, bar, liv, nath, noc, pip, pyg, ser?

Results, 2(no detailed counting data here, species only)

Results of the second night (06/07 August), part 1

Site number

Place, habitat Time (start of

the count)

LC, duration(min)

PC, duration(min)

LC, bats found PC, bats found

7 Lake Moša, SE-shore

22.51 30 M, das, liv, mur?, nath, noc, ser?

8 Small lake, W-shore

23.36 30 M, liv, mur?, nath, noc, pyg

9 Streva canyon, bridge

00.47 15 E, nath, noc, pyg

10 Lake Streva, N-shore

01.36 15 E, M, nath

11 Lake Streva, E-shore

02.11 15 M, nath, pyg

12 Forest path by Lake Streva

02.31 20 0

13 Lake Streva, S-shore

03.19 15 P, nath

Results, 3(no detailed counting data here, species only)

Results of the second night (06/07 August), part 2

Site number

Place, habitat Time (start of the count)

LC, duration(min)

PC, duration(min)

LC, bats found PC, bats found

14 Lake Spindžius, W-shore

03.44 15 bar, bm, liv, noc, pip

15 Lake Vilkokšnis, N-shore

04.21 15 liv, nath, noc

16 Forest path by Lake Vilkokšnis

04.46 15 noc

17 Forest path by Lake Spindžius

05.07 18 noc, sp24

Total, proved(10 + 1 + 2? species)

53 150 noc, sp24 E, M, P, bar, bm, das, liv, mur?, nath, noc, pip, pyg, ser?

Total results(no detailed counting data here, species only)

Total results of two nights (05/06 and 06/07 August 2005)

Summary of 17 sites

LC, duration(min)

PC, duration(min)

LC, bats found PC, bats found

Total, proved(11 + 1 + 1?

species)

141 345 E, M, liv, nath, noc, pyg, ser, sp24

E, M, P, bar, bm, das, liv, mur?, nath, noc, pip, pyg, ser?

Map 6: Results on rare bat species from August 2005(general map with the results on rare bats from August 2005)

Conclusions

17 sites were studied in Aukštadvaris area during two nights in August 2005. As a result, 11 bat species were proved. Additional species might have occurred, the sounds of which are preserved in an electronic database but thus far remain unidentified.

Detector-based counts revealed the following common species living in the area: Pipistrellus nathusii/livonicus (found at 14 sites), Nyctalus noctula (12 sites), Myotis daubentonii (7 sites), Pipistrellus pygmaeus (5 sites).

Other species were relatively rare, they were found only at a few sites. Those species were the following: 5) Eptesicus nilssonii (4 sites), 6) Barbasella barbastellus (3 sites), 7) Pipistrellus pipistrellus (2 sites), 8) Eptesicus serotinus (1 site proved; probably more animals were found at other sites, but not identified on species level), 9) Myotis brandtii/mystacinus (1 site), 10) Myotis dasycneme (1 site), 11) Plecotus sp., probably auritus (1 site; this bat is hard to find using an ultrasound detector).

From habitats studied, the best places of flight were situated either by relatively large bodies of water, close to trees or in relatively large and old mixed forest. These are habitats where most European boreal bats live and often concentrate during spring and summer.

Bat sounds from Aukštadvaris area, August 2005

Listening to bat sounds from recorded samples, 1

Sounds from Aukštadvaris area 2005, identified on species level – learn them well!

Species 1: aur25 Aukshtad-0806-k7 Streva jv kallas.wavSpecies 2: bar30-32 Aukshtad-0806-k8 jv kallas nolv.wavSpecies 2: bar32-33 Aukshtad-0805-k5-mets2-p5 0255 hea!.wavSpecies 3: bm45-46 Aukshtad-0806-k8 jv kallas sillake.wavSpecies 4: dau41-44 noc23-24 Aukshtad-0806-k1 baasi all jv kallas.wav

Species 5a: liv41-43 Aukshtad-0806-k9 jv kallas baasi taga hea!.wavSpecies 5b: nath39-42 pyg51-53 Aukshtad-0806-k3 kanjoni kesk sillake.wavSpecies 6: nil28-30 Aukshtad-0806-k3 kanjoni keskel sillake.wav

Species 7: noc21-22 Aukshtad-0806-k9 jv kallas baasi taga.wavSpecies 7: noc23-24 dau41-44 Aukshtad-0806-k1 baasi all jv kallas.wav

Species 8: pip45-46 Aukshtad-0806-k8 jv kallas sillake.wavSpecies 9: pyg51-53 noc21 Aukshtad-0806-k3 kanjoni kesk sillake.wavSpecies 9: pyg52-55 Aukshtad-0806-k5 jv E-kallas.wav

Species 10: ser25-27 Aukshtad-0805-aknast 0122 hea!.wav

Listening to bat sounds from recorded samples, 2

Sounds from Aukštadvaris area 2005, not identified thus far – can you help?

aurx-serx26-27 Aukshtad-0805-k1-p13 0024.wavdaux42-45 Aukshtad-0805-k1-p2 2236 oja kallas.wav

leix-serx25-26 Aukshtad-0806-k1 2317.wavliv42-43 soc-4imp Aukshtad-0806-k8 jv kallas sillake.wav

murx24-25 Aukshtad-0806-k1 2329 baasi all jv kallas.wavmurx25-29 Aukshtad-0806-k1 2326 baasi all jv kallas.wav

pipx43-47 Aukshtad-0805-k6 0414.wav

serx24-26 Aukshtad-0806-k1 2302.wavserx25-28 Aukshtad-0806-k1 2304 baasi all jv kallas.wavserx27-28 nath35-37 Aukshtad-0805-k6 0409 sild 2jv.wav

sp22-25 Aukshtad-0806-k1 2322 baasi all jv kallas.wavsp24-26 Aukshtad-0806-k1 2329 baasi all jv kallas.wav

References

Keppart, V., Masing, M. & Lutsar, L. 2005. Nahkhiired Luual. [Bats at Luua.] Rmt.: Belials, V. (koost.) Luua Metsanduskool. Artiklid ja uurimused, 4. Luua, 77—88.

Masing, M. 2004. A new mammal species described on 01 April 2004. – Eptesicus, 3. (www.hot.ee/eptesicus)

Masing, M. 2006. Perekonna Pipistrellus hääldiagnostika Põhja-Euroopas ja pügmee-nahkhiire (Pipistrellus pygmaeus Leach) leiud Eestis. – Eesti Looduseuurijate Seltsi aastaraamat, 84, 185—206. [Sound diagnostics in the genus Pipistrellus (Chiroptera, Vespertilionidae) in northern Europe and the finds of Pipistrellus pygmaeus in Estonia.]

Masing, M., Lutsar, L. & Lotman, K. 2002. The improved route counting method to monitor boreal bats. – 9th European Bat Research Symposium, 26—30 August 2002. University of Le Havre, France. Abstracts, p. 13.

Masing, M., Lutsar, L. & Lotman, K. 2005. Line counting and point counting of foraging bats in Estonia, a comparison. – Le Rhinolophe, 17, 121—125.

End of presentation

Thank you!

Aukštadvaris, 18 August 2011

Matti Masing & Kazimieras Baranauskas