Blasius's horseshoe bat
Rhinolophus blasii
Vincent Rufray · MMJ4+43R
Key facts in one look
- Size
- 7–15 g, wingspan 27–31 cm
- Diet
- Insectivore, mainly moths
- Status in Georgia
- Very rare, in caves
- Habitat
- Karst caves
- Family
- Rhinolophidae
- Conservation
- EN / LC
Blasius's horseshoe bat (Rhinolophus blasii) is one of Georgia's least known bats: up to 2022 it had only six records in the country, all from caves. It is a small animal of 7–15 g with a horseshoe-shaped leaf of skin on its nose. It hunts in flight at night and feeds almost only on moths. It looks very much like the Mediterranean horseshoe bat, and even specialists find the two hard to tell apart in the field. It is not dangerous to people, but do not touch or disturb bats hanging in a cave.
Identification
Blasius's horseshoe bat: how to identify it
A medium-sized horseshoe bat with a forearm of 41–51 mm and a wingspan of 27–31 cm. The fur is fluffy, light brown or yellowish brown, and the belly is whitish. The most reliable feature is in the noseleaf, but it can only be seen on a bat held in the hand. So in the field you cannot tell it from the Mediterranean horseshoe bat by eye.
Head and body 46.5–54 mm, tail 20–31 mm, forearm 41–51 mm, weight 7–15 g. Its size almost exactly matches the Mediterranean horseshoe bat, so size will not help you separate them.
Its nose carries a horseshoe-shaped leaf of skin. In the middle, above the nostrils, a narrow, tall, pointed process rises like a horn. The "saddle" in front of it is wedge-shaped and narrows towards the top, which is why it is sometimes called the peak-saddle horseshoe bat. In the Mediterranean horseshoe bat the same process curves forward and down, and the saddle has parallel sides and a broad top.
The back is light brown or yellowish brown, and the hairs have cream bases. The belly is greyish, white or cream. The fur on the nape is a little lighter and shows as a pale band, and there is a dark brown patch under each eye.
The greater horseshoe bat is clearly bigger, with a wingspan of 35–40 cm and a weight of up to 30 g. The lesser horseshoe bat is smaller, at 5–9 g. Blasius's horseshoe bat sits in between. Its echolocation call lies at 85–98 kHz, and the Mediterranean horseshoe bat's at 100–109 kHz, so an ultrasound detector sometimes helps a specialist. Do not catch the bat yourself: only a bat researcher can confirm the species.
Blasius's horseshoe bat is a cave bat: in Georgia it has only been found in caves. Records from 2004–2022 come from Ghliana Cave (Imereti), Prometheus Cave at Kumistavi, two caves near Zodi and Gogoleti Cave, at about 170–900 m above sea level. It usually spends summer and winter in neighbouring caves. In Europe it is tied to limestone country, often near streams in shrubby and wooded places. It depends heavily on water.
Blasius's horseshoe bat feeds almost only on moths. It catches most of them in flight, but it will also pick an insect off a leaf or the ground. It can hear the flutter of a moth's wings as it settles, flies over, lands, grabs it and takes off again. It flies slowly and nimbly, turns sharply and can hover for a moment. It drinks by skimming the water surface in flight.
Blasius's horseshoe bat is nocturnal. It spends the day hanging freely upside down from a cave ceiling, often in a sluggish, torpid state. It usually lives in small colonies of 20–40 animals, but groups of 3–4 and lone bats are common too. It shares caves with other horseshoe bats, mouse-eared bats and bent-winged bats. In summer, females gather with their young in maternity colonies of 30–400 animals. Mating probably takes place before hibernation, and the embryo's development pauses until spring. It gives birth to one young a year. In Europe it usually begins hibernating in November, once the temperature drops below 14°C, and it spends the winter in caves. It does not migrate. If you see a bat hanging in a cave, walk past quietly and quickly.
In Georgia, Blasius's horseshoe bat is Endangered (EN B1a+2ab(iii), 2021 national assessment). Its range in the country covers less than 500 km², and the places it actually occupies cover less than 50 km². Its numbers are falling. Globally the species is not threatened (LC, 2016), but its numbers are falling there too: it has already died out in Italy and is considered one of the rarest horseshoe bats in Europe. Its main threats are disturbance of colonies and the destruction of caves and other roosts. The loss of Mediterranean woodland where it hunts is a threat too. In Georgia, Ghliana Cave, where it has been found, was rated the most threatened of the assessed caves with colonies, mainly through disturbance by people. For a species this rare, losing a single cave is a serious loss.
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Yes, but it is very rare. It is known from only a few caves in the country, including Ghliana Cave and Prometheus Cave at Kumistavi. Up to 2022 it had only six records in all. That is why it is assessed as Endangered in Georgia.
In the field you almost cannot. Both have a similar size and colour. The difference is in the noseleaf: in Blasius's horseshoe bat the central process is tall, straight and pointed like a horn, and the saddle narrows towards the top. In the Mediterranean horseshoe bat the process curves forward and the saddle is broad at the top. This can only be seen on a bat held in the hand, so a bat researcher confirms the species.
It is small: it weighs 7–15 g, its head and body measure 46.5–54 mm and its wingspan is 27–31 cm. It is clearly smaller than the greater horseshoe bat and larger than the lesser horseshoe bat. In size it almost exactly matches the Mediterranean horseshoe bat.
Almost only moths. It catches most of them in flight and sometimes picks them off a leaf or the ground. It flies slowly and nimbly and can hover for a moment.
No, it is not venomous and does not attack you. But do not touch any bat with bare hands, because rabies cannot be ruled out by looking. If it bites or scratches you, wash the spot with soap and water for at least 15 minutes and see a doctor at once. In an emergency, call 112.
In Georgia it is assessed as Endangered (EN, 2021). Worldwide it is not threatened (LC, 2016), but its numbers are falling. Its main threats are disturbance of colonies in caves and the destruction of roosts. 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.
