Investigation of bats in the Darkhad wetlands

Darkhadyn Khotgor wetland located in the northern part of Mongolia and has small and large rivers such as Shishged, Tengis and the lake ‘Tsagaannuur’ (eng. White lake) which are the upstream of Yenisei River. It is a land of rich biodiversity and pristine water with extreme continental climate. Darkhadyn Khotgor wetland area is composed of three ecological zones of Siberian taiga, forested steppe and meadow valley. It is surrounded by Ulaan Taiga strictly protected area (SPA) in the western part, Khoridol Saridag Mountains SPA in the eastern part, Khuvsgul National Park (NP) and the watershed of Tengis and Shishged rivers in the northern part. We conducted the bats survey in Dood Tsagaan lake (N51⁰23’22.3, E99⁰19’23.4altitude-1569m), Usariin Am (N51⁰26’09.6, E99⁰12’03.7 altitude-1542m), Tengis river (N51⁰29’05.9, E99⁰03’33.4altitude-1563m) and Khuit cave (N51⁰11’04.2, E99⁰20’35.8altitude-1730m) on June 21 — July 07, 2010, September 16–30, 2010 and October 15, 2012. We recorded five species of bats Myotis gracilis, Myotis petax, Myotis ikonnikovi,Plecotusognevi andEptesicus nilssonii in the study area.Bats are hibernated relatively much earlier due to short summer season in the Darkhadyn Khotgor wetland. It was revealed from the study conducted in the Huit cave of Mongolia that Ognev’s long eared bat, Ussuri whiskered bat and northern bat were hibernated in this cave. This has been the first evidence that these types of bats were hibernated in a Mongolian cave. Also, the bones of the northern bat, Ognev’s long eared bat, Ikonnikov’s bat, eastern Daubenton’s bat and Ussuri whiskered bat were found from this cave. The fact that the bats species originated from the northern part of the Palearctic region reside in Darkhadyn Khotgor, and also there is no evidence of the widely distributed species in this area shows that the Darkhad Khotgor has more extreme cold and wet climate compared to the northern forest areas of Mongolia.

Keywords: Chiroptera, Darkhad wetland, morphology, cave, hibernation, ecology

Introduction

Bats species live relatively longer and therefore they are sensitive to the changes of the particular conditions and they allow the gathering of long-term monitoring data for researchers. The swarm of bats has been gathering during cold seasons inside deep cave to hibernate and these conditions create the chances to investigate various species. The bats species feed by various blood sucking insects and some species of destructive moths inhabiting on that area and play important role for ecosystem. The zones of taiga, forest and meadow exist in Darkhad wetland and the forest animals of Siberian taiga and cold zones are inhabiting. According to the geographical zones, this area belongs to the Taiga zone of Northern large region, Khuvsgul circle of Siberian sub zone. Currently the specialized investigation of Darkhad wetland bats species is missing and the investigations of eastern Daubenton’s bats were carried out by A. G. Bannikov (1954), the eastern Daubenton’s bats and northern bats are studied by M.Stubbe (1994).

Research materials and methodology

Our investigations aimed to determine the quantities of bats species in Darkhad wetland and we gathered some biological and ecological data. We conducted the investigations of Darkhad wetland bat species between June 21 and July 07, 2010, from 16 to 30 of September, 2010 and October 15, 2012 in the areas of Khashgirdag khad (Crying Rock) of Dood Tsagaan nuur (Lower White Lake) (N51⁰23’22.3, E99⁰19’23.4 Alt-1569м), Usariin am (N51⁰26’09.6, E99⁰12’03.7 Alt-1542м), Tengis river (N51⁰29’05.9, E99⁰03’33.4 Alt-1563м) and Khuit cave (Fig. 1) (N51⁰11’04.2, E99⁰20’35.8 Alt-1730м). In addition, we have gathered data from literatures those research papers kept in the library of Mongolian State University of Education such as one specimen gathered from Darkhad wetland in 2005, one specimen collected from nearby area of Renchinlkhumbe village in July 2007 have been used for our research. During our investigation, we have placed two nets of 9x4 meters made by synthetic material designated for catching of bats species in the meadow of river, riverbed, clearing area within trees with elevation of 5–6 meters and from 9pm to 01am and the captured bats species have been kept inside the designated net bags. The measurements of their bodies have been performed in the next morning and released after the detailed determination. The skull bone of bats species taken from Khuit cave are examined in the laboratory. Climate data measured by Kestrel-3000 equipment.

The maximum and minimum of morphometrical measurements, average and standard deviations of the captured bats species during this investigation are estimated by Microsoft Office Excel statistical program.

Fig. 1: Hibernating and habitat conditions of bats, background of Khuit cave

Fig. 2: Habitat conditions of Darkhad wetland bats, Usariin am

Results

Five species of bats which belong to three classifications have been registered from Darkhad wetland such as three species of Myotis, one species of Eptesicus and one species of Plecotus.

1.       Ussuri whiskered bat — Myotis gracilis Ognevi, 1927

Ussuri whiskered bats are commonly distributed in the northern areas of palearctic and northern Mongolia. They mostly feed by microlepidoptera, homoptera, coleoptera, diptera and aranaea. They are noted to the classification of `Data deficient` according to the Mongolian Red List of Mammals [5] by the evaluation of region.

Ussuri whiskered bat was not registered previously in Darkhad wetland and we found and registered one specimen from the Khashgirdag cliff on the bank of Dood Tsagaan nuur, 15 male and female specimens on June 26 from the forest of Shishged river of Usariin am (Fig. 2), one specimen from Tengis river bank and the hibernating and gathering 1–12 individuals in Khuit cave (Fig. 3). Their bodies were seemingly inflexible, unable to fly and they made weak sound when we touched their bodies. In addition, we collected 31 skull bones of Ussuri whiskered bats from this cave. The female bats captured from Usar mouth were pregnant.

The average weights of the Ussuri whiskered bats captured during this investigation are as follows: (n=23) 5–8g (6.3±0.7g), length of head-body (n=26) 38.8–53.2mm (47.7±2.7mm), length of tail (n=26) 30.2.8–43.5mm (37.5±3.1mm), length of forearm (n=26) 33.5–39.2mm (37.1±1.3mm), length of 5^th finger (n=26) 42.2–48.7mm (45.4±1.8mm), length of 3^th finger (n=26) 52.3–59.9mm (56.4±2.1mm), length of thumb (n=26) 4.2–6.8mm (5.8±0.6mm), claw length of thumb (n=26) 1.1–2.5mm (1.9±0.3mm), length of ear (n=26) 11–15.2mm (13.2±1.2mm), length of tragus (n=26) 5.7–8mm (6.9±0.5mm), length of tibia (n=26) 14.3–18.6mm (16.4±1.0 mm) and length of hind foot (n=26) 5.8–8.1mm (6.9±0.4mm).

Fig. 3: Ussuri whiskered bats hibernated inside Khuit cave

Fig. 4: Myotis gracilis Ognevi, 1927 from Darkhad wetlands

2.     Eastern Daubenton’s bat — Myotis petax Hollister, 1912

Eastern Daubenton`s bats are widely distributed from western Siberia to Korea and Japan and inhabiting in the forest and forest-steppe zones near to water sources. Chironomidae, lepidoptera, plecoptera, ephemeroptera, trichoptera and coleoptera are mostly feed by small insects. They belong to the classification of `Least Concern` according to the Mongolian Red List of Mammals [5] by the evaluation of region.

V.Elpatevskii had collected the Daubenton`s bats from the south-west areas of Darkhad wetland [3]. The joint Mongolian and German team for biological investigation collected two male specimen from Renchinlkhumbe village territory (N51⁰12’, E99⁰23’) on August 4, 6, 1990 [6].During our investigation we have found and registered one female pregnant, Daubenton`s bat which inhabited alone inside the gap of Khashgirdag Cliff near to the bank of Dood Tsagaannuur lake and 11 male and female specimens from the forest of Shishged river of Usar mouth on June 26, one specimen from Tengis river bank and 94 skull bones of eastern Daubenton`s bats from Khuit cave.

The average weights of Daubenton`s bat captured during our investigation are as follows: (n=14) 6–10g (7.8±1.0g), length of head-body (n=14) 43.2–55mm (51±3.1mm), length of tail (n=14) 37.8–47.3mm (41.4±2.6mm), length of forearm (n=14) 38.3–41.3mm (39.9±1.0mm), length of 5^th finger (n=14) 46.2–53.3mm (49.6±1.9mm), length of 3^th finger (n=14) 56–64.1mm (61.5±2.3mm), length of thumb (n=14) 5.5–7.6mm (6.8±0.6mm), claw length of thumb (n=14) 1.5–3.2mm (2.5±0.4mm), length of ear (n=14) 12–14.9mm (13.2±0.8mm), length of tragus (n=14) 4.8–6.8mm (6.1±0.6mm), length of tibia (n=14) 14.6–21.1mm (17.5±1.4mm), and length of hind foot (n=14) 7.3–8.9mm (8.3±0.4mm).

3. Ikonnikov’s bat — Myotis ikonnikovi Ognev, 1912

These bats distributed through Khentii, Khangai mountains, western Khyangan mountains, forest along Selenge river basin and forest steppe. They belong to the classification of `Data deficient` according to the Mongolian Red List of Mammals [5] by the evaluation of region. This species have not been registered from Khuvsgul area previously. We collected and determined one specimen from Darkhad wetland during the research conducted in 2005. Five skull bones are found in 2010 and 2012 during the research in Khuit cave. The external measurements of the captured specimens are as follows: head-body-length 42mm, tail length 33mm, forearm 32.3mm, length of 5^th finger 39mm, length of 3^th finger 49mm, length of thumb 4.6mm, claw length of thumb 1.4mm, ear length 9.5mm, tragus length 5.5mm, tibia length 15.7mm and hind foot length 5.0mm. The skull measurements are (n=1): condylobasal length 12.5mm, zygomatic width 7.1mm, braincase width 6.2mm, maximum braincase height 6.0mm, inter-orbital constriction width 3.4mm, length of maxillary tooth row (C-M³) 5.0mm and mandible length is 10.0mm.

Fig. 5: Myotis petax Hollister, 1912 from Darkhad wetlands

Fig. 6: Myotis ikonnikovi Ognev, 1912

4. Ognev’s long eared bat — Plecotusognevi Kishida, 1927

Ognev’s long eared bat distributed in the areas of northern forests and forested steppe of Asia. In Mongolia they distributed in Mongolian Altai, Khangai, Khuvsgul, Khentii, western Khyangan taiga, forest steppe and steppe zones. Its major nutrition is lepidoptera of trees, blood sucking insects and they feed on significant number of them. Also they feed on caterpillars of butterflies and even aranaea. It referred to the classification of `Least Concern` according to the Mongolian Red List of Mammals [5] by the evaluation of region.

We registered Ognev’s long eared bat in the nearby area of Deed turuu on the territory of Ulaan-uul village in 2004 during the investigation. Totally 81 skull bones of Ognev's long eared bat were collected from Khuit cave in 2010 and 2012. One hibernated species from this cave was identified. We had not recorded alive individual of Ognev’s long eared bat from Khuit cave on Sept, 2010, however there were some individuals flying in the cave on Sept 13^th, 2012, and we collected 7 specimens of this species, those were hibernated on the cave on Oct 15^th. During our investigation we captured one female specimen on June 27 from Tengis river area of Renchinlkhumbe village. Its body weight was 11g, length of head-body 54.9mm, length of tail 43.2mm, length of forearm 41.6mm, length of 5^th finger 54.3 mm, length of 3^th finger 74.2mm, length of thumb 7.1mm, claw length of thumb 3.1mm, length of ear 38.3mm, length of tragus 17.4mm, length of tibia 21.9mm and the length of hind foot is 8.0mm.

5. Northern bat — Eptesicus nilssonii (Keyserling et Blasius, 1839)

Northern bat is commonly distributed in Khangai, Khentii, Khuvsgul, northern taiga of Mongolian Altai and the forest-steppe zone. It eats insects such as noctuidae, hymenoptera and coleopteran. It referred to the classification of `Least Concern` according to the Mongolian Red List of Mammals [5] by the evaluation of region.

The joint Mongolian and German team for biological researches gathered one female specimen from Renchinlkhumbe village area (N51⁰12’, E99⁰23’) on August 4, 1990 [6].We captured one northern bat on June 24, 2007 from the area of Renchinlkhumbe village. In addition, one specimen was registered from Kharmai river (N51⁰20’, E99⁰20’) near to Tsagaan nuur village center in 2009. Three skull bones was found and gathered from Khuit cave in 2010 and 2012 during investigation and two male specimens that hibernated near cave mouth was found and registered. The measurements of the captured specimens are as follows: weight 12g, head-body-length 57.5mm, tail length (n=2) 30.9–37.0mm, forearm (n=2) 39.5–41.5mm, length of 5^th finger 44.9mm, length of 3^th finger (n=2) 64.0–65.0mm, ear length 12.8mm, tragus length 5.1mm.

Fig. 7: Ognev’s long eared bat hibernated inside Khuit cave

Fig. 8: Northern bat hibernated inside Khuit cave

Fig. 9: There were numerous dead bats inside the cave

Discussion

Ognev’s long eared bat, Ussuri whiskered bat and northern bat were identified while they were hibernating in Mongolian bigger cave Khuit which was not investigated previously. In addition, 214 skull bones of bats such as Ussuri whiskered bat, eastern Daubenton’s bat, Ikonnikov’s bat, Ognev’s long eared bats and northern bats were found although they have not been discovered (Table 1) alive (Fig. 9). Our investigation previously determined that Ognev’s long eared batare hibernating and spending winter in ‘Suugt‘ cave of north-eastern Khentii and it has the permanent habitat [2]. It is the first proof that these species are inhabiting and hibernating in Khuit cave and it depicts that they spend winter in Mongolian conditions. Khuit cave was fairly cool, humid, with water running down the cave walls and ice crystals resembling stalactites were grown in some places of this cave.

Table 1

Structure of species of Khuit cave bats

When we arrived to Darkhad wetland on September 16, the weather became quite cold and outdoor water was frozen and few insects were observed during daytime, insects and bats did not fly during the nights at all. In 2012, Oct 15^th, air temperature of Khuit cave was -0.4⁰C and air humidity was 50 % at 20 meters from the cave mouth, however in the middle of cave the air temperature -0.6⁰C and humidity 80 % and there were ice crystals on the ground and wall. Northern bat was flying until the beginning of the cold days of October near Ulaanbaatar city [3] whereas the bats were hibernating in Darkhad wetland earlier than the bats of other Mongolian areas due to Darkhad wetland has colder weather.

The comparative Cluster analysis whether the bats species which distributed in Mongolian Khangain mountains, western Khyangan mountains, basin of Onon river and bats species residing in Argarakanskaya cave situated near Baikal lake [4] and species hibernating in Yakutia [1] are similar with the composition of species of Darkhad wetland bats was performed (Fig. 10). This Cluster Analysis showed that species structure of bats residing in Russian Yakutia with cold weather is same with the species composition of Darkhad wetland bats [1] and it demonstrates that Darkhad wetland has fairly cold weather.

Fig. 10: Cluster analysis of the similarity of bats species of Darkhad wetland and other areas

Further, it is possible to comprehensively investigate numerous caves of Darkhad wetland and Khuvsgul area whish have not been studied to date, numerous residing major spaces for bats, gather data related with biology and ecology of bats and subsequently discover the numerous new species. If we can continue researches of bats in the future we expect that we might register the species such as Myotis aurascens,Myotis frater, Myotis bombinus,Myotis dasycneme, Murina hilgendorfi, Vespertilio murinus which are inhabiting in the adjacent areas of Mongolia and Russian Federation.

The longterm monitoring of bats relying on caves and other residing spaces will allow the indirect survey of the regional meteorological changes through the distribution of the relatively arid species.

Conclusion

The five species of three genus of Vespertilionidae Gray, 1821, three genus of Myotis gracilis Ognevi, 1927 — Ussuri whiskered bat, Myotis petax Hollister, 1912 — eastern Daubenton’s bat, Myotis ikonnikovi Ognev, 1912 — Ikonnikov’s bat, Plecotusognevi Kishida, 1927 — Ognev’s long eared bat and Eptesicus nilssonii Keyserling et Blasius, 1839 — northern bat are distributing in this area.

Ikonnikov’s bats are recorded first time from Darkhad wetland of Khuvsgul.

We identified that eastern Daubenton`s bats, Ikonnikov bats are hibernating together with the northern bat, Ognev’s long eared bat, Ussuri whiskered bats which are residing in caves in Darkhad wetland.

The distribution of northern bat, Ognev’s long eared bat, eastern Daubenton`s bats, Ussuri whiskered bats which residing in the far northern areas of bats distribution of Palearctic region are distributing in Darkhad wetland and these conditions show that there is colder weather. The Myotis aurascens, Vespertilio murinus which are distributed most commonly in Mongolia which prefer the arid and warmer conditions were not registered in Darkhad wetland and it is related with its humid, cool weather.

The structure of bats species near Darkhad wetland is similar with Yakutian structure of species and it depicts that currently Darkhad wetland has colder weather comparatively with other forest areas of northern Mongolia.

References:

1.                   Anufriev, A.I. (2007). Bat hibernacula in Yakutia. –Plecotus et al. 10: 55–61.

2.                   Ariunbold, J. (2002). Several issues of species structure of Mongolian bats, their distribution and ecological conditions. Master`s thesis. UB.

3.                   Bannikov, A.G. (1954): The Mammals of the Mongolian People’s Republic. Academy of Science of the U. S. S.R., Moscow, Russia. p.669

4.                   Botvinkin, A.D., Osintsev A. V., Tiunov M. P. (2003). Hibernating of bats inside Argarakanskaya cave in Predbaikalie. — State national Park `Baikal-Lenskii` 3: 108–111.

5.                   Clark, E. L., Munkhbat, J., Dulamtseren, S., Baillie, J. E. M., Batsaikhan, N., Samiya, R. and Stubbe, M. (compilers and editors) (2006). Mongolian Red List of Mammals. Regional Red List Series. Vol. 1. Zoological Society of London, London.

6.                   Stubbe, M., (1994). Die wissenschaftliche Sammlung mongolischer seaugetierarten am institute fuer Zoologie. Wissenschaftliche Hausaurbeit zur ersten staatsprufung fur das lehramt an Gimnasien.