Lesser mouse-eared bat
Myotis blythii
Kaloust Paragamian · Κρήτη
Key facts in one look
- Size
- Body 5.8–7.7 cm, wingspan 38–40 cm
- Diet
- Insectivore: grasshoppers, other insects
- Status in Georgia
- Native; frequent in caves
- Habitat
- Caves; wooded and open country
- Family
- Vespertilionidae
- Conservation
- LC / LC
The lesser mouse-eared bat (Myotis blythii) is one of the bats recorded most often in Georgia's caves. In summer, nursery colonies of 4,000–8,000 bats, shared with Schreiber's bent-winged bat, gather in Ghliana and Samertskhle Klde caves. It is a fairly large Myotis: its wingspan is 38–40 cm and its weight 15–30 g. It hunts in open country and often takes grasshoppers and other insects straight off the ground. If a bat flies into your home, do not catch it with bare hands: open a window and give it time to leave.
Identification
Lesser mouse-eared bat: how to identify it
A large, greyish-brown Myotis with a whitish belly, an almost bare pink face and medium-length, narrow ears. It looks very much like the greater mouse-eared bat. In caves it often hangs in hundreds or thousands, mixed with other species.
Size: the body is 5.8–7.7 cm, the tail 4.5–6 cm, the forearm about 50–63 mm, the wingspan 38–40 cm and the weight 15–30 g. It is one of the large Myotis bats of Europe.
The ears are of medium length and fairly narrow. The small flap inside the ear, the tragus, has a pale tip with no dark spot.
It looks very much like the greater mouse-eared bat (Myotis myotis), but its snout is clearly shorter, its ears narrower and shorter, and its belly usually paler. Only specialists tell the two apart, by measurement.
The back ranges from grey to light brown and the belly is greyish-white. The hairs are dark at the base. The wings are large and broad.
Colour
The back is grey, greyish-buff or light brown and the belly greyish-white. The fur is long and dark at the base. The face is almost bare, with pink skin.
Swatches are illustrative. Do not identify a species by colour alone.
The lesser mouse-eared bat lives in wooded and dry landscapes. It spends the day and the winter in caves, grottoes and buildings. It hunts in open country. It ranges from the Mediterranean through the Caucasus and western and central Asia to the Altai and northern China. In Georgia it is one of the most frequent cave bats: 120 records are known, both from before 1999 and from recent decades. They run from west to east, from Zugdidi, the Kutaisi area and Borjomi to Tbilisi, Lagodekhi and the David Gareja caves. Ghliana and Samertskhle Klde caves hold its largest nursery colonies.
The lesser mouse-eared 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
- Region with records
The lesser mouse-eared bat eats insects. It hunts in open country, catching insects in the air or taking grasshoppers, bush crickets and other insects off the ground. It leaves its roost late to hunt. Its flight is calm but agile.
The lesser mouse-eared bat is sedentary and does not migrate far. In the north of its range it winters in underground roosts. Mating takes place after the young are weaned or at the winter roosts. In summer it forms nursery colonies of up to several thousand bats, often with other species; males often stay with the females. The mixed colony in Ghliana Cave varies from 4,000 to 8,000 bats from year to year and peaks in late July and early August. Each female has a single young in late May or June. Pregnancy lasts about 60 days and nursing about 30 days.
Globally the lesser mouse-eared bat is rated Least Concern (LC, 2016), though its numbers are falling. Threats include pollution, changes in land use and disturbance of caves: in Andalusia construction noise cut its numbers from 30,000 to 14,000 between 1994 and 2002, and in Syria and Turkey herders light fires at cave mouths. In Georgia the 2021 national assessment rates it Least Concern (LC), with a stable population. Its fate depends on a few large caves. The colony in Ghliana Cave is the most threatened, and giving Samertskhle Klde Cave protected status would improve this species' standing. The land around the caves, where the bats feed at night, also needs protection.
Related guides
Continue with related pages
Yes, and it is common. 120 records are known, from western to eastern Georgia. It is one of the most frequent bats in caves. In summer thousands of bats gather in Ghliana and Samertskhle Klde caves.
It is hard by eye. The lesser mouse-eared bat has a shorter snout, narrower and shorter ears and usually a paler belly. The tip of its tragus is pale, with no dark spot. Only specialists settle the species, by measurement, 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.
Insects, especially grasshoppers and their relatives. It hunts in open country. It catches prey in the air and also picks it off the ground. It leaves its roost late, at dusk.
It is not threatened, but it depends on large caves. Globally, and in Georgia's 2021 national assessment, it is rated Least Concern (LC). In Georgia its largest colonies sit in only a few caves, and some of them are threatened by human disturbance. So do not disturb bats in caves.
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.
