Parti-coloured bat
Vespertilio murinus
Nikolai Kondakov · Abkhazia Georgia field photo
Key facts in one look
- Diet
- Insectivore: mosquitoes, midges, moths
- Status in Georgia
- Native; poorly studied
- Size
- Body 4.8–6.4 cm, weight 11–24 g
- Habitat
- Mountains, forest, towns; building crevices
- Family
- Vespertilionidae
- Conservation
- LC / DD
The parti-coloured bat (Vespertilio murinus) is easy to pick out by its two-tone fur: the dark brown hairs of the back end in silvery white, and the belly is white or grey. The face, ears and wings are almost black. It is a migrant: it covers hundreds of kilometres, and the longest recorded journey is 1,780 km. In autumn, during the mating season, its bird-like twittering can be heard even by people. In Georgia it is known mainly from the west and centre, from Poti and Sokhumi to Borjomi. If a bat flies into your home, do not catch it with bare hands: open a window and give it time to leave.
Identification
Parti-coloured bat: how to identify it
A medium-sized, robust bat with narrow wings and short, broad, rounded ears. The fur on the back is dark with silvery tips and looks "frosted". This two-tone fur sets it clearly apart from Georgia's other bats.
It is medium-sized: the body is 4.8–6.4 cm, the wingspan 26–33 cm and the weight 11–24 g. The wings are narrow, and its flight is fast and agile, like that of the noctules.
The fur is the main feature: the hairs of the back are dark brown at the base and silvery white at the tips. The belly is white or grey and stands out sharply from the back. The face, ears and wing membranes are black or dark brown.
The serotine and the noctule have no such silvery tips on their fur. Still, bats are hard to tell apart in flight, so do not catch one to identify it: that is a job for specialists.
Colour
The back ranges from reddish to dark brown, with silvery white tips that give it a frosted look. The belly is white or grey. The face, ears and wings are black or dark brown.
Swatches are illustrative. Do not identify a species by colour alone.
The parti-coloured bat lives in mountains, steppe and wooded country, but it adapts well to human surroundings and often occurs even in large cities. In summer it hides in crevices in buildings and trees. In winter it prefers crevices in buildings to underground sites, though in Georgia it has also been found underground. In Georgia it has been found near Poti and Sokhumi, in the Ritsa and Pskhu-Gumista reserves, near Tkibuli and Kharagauli, in Borjomi and the Borjomi gorge, and near Tsona. These are individual records, not a sign that it is common everywhere in these places.
The parti-coloured bat map combines public iNaturalist observations. Regions are taken from the records-by-region table, and the status column separates regions with enough records from regions with too few records. Record counts reflect observation effort rather than population density. Records are still too few: no region has enough records yet.
Data: Reptiles.ge + iNaturalist · Methodology
- Field observation
- Several records in one spot
- Photo record
- Region with records
The parti-coloured bat feeds on small flying insects: mosquitoes, midges, caddisflies and moths. It hunts in the air over open space, often in swarms of insects. It leaves to hunt after dusk and flies 20–40 m up: over streams and lakes, above forests or around street lights. It finds prey by echolocation, mostly at 25–27 kHz.
The parti-coloured bat is a migratory species. Flights of up to 900 km are known, and the longest was 1,780 km. It hibernates alone from October to March and can withstand frost down to −5 °C. In cold weather it may not leave its roost at all. In autumn, during the mating season, it gives a call like a bird's twitter. In May–July females gather in nursery colonies, usually of about 50 animals, sometimes several hundred. Females usually have twins. The young become independent in under six weeks, after which the females leave the colony. It lives up to 12 years.
Globally the parti-coloured bat is rated Least Concern (LC, 2016), with a stable population. In Georgia the 2021 national assessment rates it Data Deficient (DD), and its population trend is unknown. It is threatened mainly by disturbance and loss of roosts, as well as by insecticides and habitat change. It is listed in the Red Data Books of several Russian regions, including Moscow.
Related guides
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Mainly in the west and centre. It has been found near Poti and Sokhumi, in the Ritsa and Pskhu-Gumista reserves, near Tkibuli, Kharagauli and Borjomi, and near Tsona. Records are few, and its distribution in Georgia is not well studied.
By its fur. The dark hairs of the back end in silvery white, so the animal looks as if covered in frost. The belly is white or grey, and the face, ears and wings are almost black. The ears are short and rounded. These features do not show in flight, so do not catch the bat.
It will not attack you, but do not touch it with bare hands. A bat bite can be tiny and easy to miss. Rabies cannot be ruled out by appearance, although most bats people see are not rabid. After a bite or scratch, wash the spot with soap and water for at least 15 minutes and see a doctor; in an emergency, call 112.
Stay calm and take children and pets out of the room. Close the doors to other rooms, open an outside window or door wide and switch off unnecessary lights. Then step back and give it time: a bat usually finds the way out on its own. Do not try to catch a bat in flight.
Small flying insects: mosquitoes, midges, caddisflies and moths. It hunts high, 20–40 m up, over water, forests and open ground. In towns it often hunts around street lights, where insects gather.
Globally it is not threatened: it is rated Least Concern (LC, 2016). In Georgia the 2021 national assessment rates it Data Deficient (DD), so it is still hard to judge its condition. Disturbance and loss of roosts harm it most. If bats live in the crevices of your house, do not drive them out.
References
What this profile is based on
Species profiles are compiled from peer-reviewed literature and established biodiversity databases, and are reviewed as new taxonomic and conservation data become available.
Prepared by the Reptiles.ge editorial team from the sources listed here.
