It was a close race, as all the finishers were horseshoe bats. But collecting 38% of the total of 1,191 votes and Likes, the lesser horseshoe bat becomes the Bat of the years 2024-2025 in Romania.

The lesser horseshoe bat (Rhinolophus hipposideros), weighing 4-7 grams, is not only the smallest of the horseshoe bats, but it is also one of the smallest in Romania. Despite its size, among the country’s species, it emits ultrasound with the highest frequency, at 108-114 kHz. As the name suggests, it belongs to the genus of horseshoe bats, that is, bats that emit ultrasound not through their mouths, as other species do, but through special, horseshoe-shaped nasal lobes.

Listen here the typical whistle of horseshoe bats!

The species is present in all major areas of Romania, but most observations come from the hill and mountain areas, these being bats hibernating in underground shelters, or ultrasounds emitted in feeding habitats. In the online database of Romanian and Moldovan bats, which will be officially launched in autumn this year, the species already has over 1.000 observations from the period 2010-2024.

In winter we can see the species in caves, mine galleries or cellars. During hibernation, even if bats hang close to each other, they never touch, unlike other species, which form very compact colonies. By far the largest known hibernation population in Romania is located in the Grădiștea Muncelului – Cioclovina Nature Park. Over 1.000 bats of the species hibernate in a system of 4 closely situated caves. Significant hibernation populations are also known from the Vârghișului Gorge, from the Pădurea Craiului Mountains, the Metaliferi Mountains, and the Mehedinți Plateau.

One of the largest european colonies of the species is in the United Kingdom, in an usual location, an underground “fridge” (photo below, author: Vincent Wildlife Trust), with circa 1.000 bats hibernating on a small surface. The largest hibernation colony of the species in Europe is located in the Javoříčské Cave in the Czech Republic, where we also visited as part of an international project we are part of. There are over 1.500 bats hibernating in the cave.

The species prefers to hunt insects in deciduous and mixed forests, on woodland edges, in wooded meadows and in orchards. It has short wings, which allow extremely precise maneuvering during flight, thus the species hunts easily even in dense vegetation. But also due to its short wings, the species has a slow flight, and thus does not travel long distances to its feeding habitats. On average, they fly at a distance of 1-4 km from the roost. Once in the feeding habitats, the species consumes a wide variety of insects, including mosquitoes and moths. The species does not fly long distances even during seasonal migration. The distance between the underground hibernation sites and the places where the nursery colonies are formed are under 20 km, the records being at 140-150 km.

In warm seasons, the lesser horseshoe bat uses the attic of buildings, which usuallt have high temperatures, of above 30˚C. This is the place females of the species gather to form nursery colonies. The maximum possible age for the species is not precisely known, but proven records are between 14 and 21 years. The largest breeding colony of the species in Romania consists of 100-150 females, although at the moment the survival of the colony is called into question, due to the changes made to the building and in the detriment of the colony. Another important breeding colony of the species consists of 40-60 females, in the Despicătura Cave in Domogled National Park – Cernei Valley. Being in a very exposed location (a hotel parking lot), the cave has recently received a bat-friendly gate as part of our cross-border project in the Banat region. But the underground environment was also cleaned of the remains of the rusted (unused) thermal water pipelines, as part of our international LIFE+ project.

The species is strictly protected and included in national and European legislation. The biggest threat to the colonies is the renovation of those buildings that have nursery colonies during summer.. If these renovations do not take into account the presence of bats (in the sense of preserving the original details of the building’s attic), the colony may fall apart, or it may lead to high mortality among the pups.

The lesser horseshoe bat is the flagship species for the international project LIFE+ Podkowiec Towers, with all partner countries (Poland, Czech Republic, Slovakia and Romania) having components in their projects to protect roosts of the species. For example, in Romania we will strengthen the entrance to a collapsing mine gallery, where there is a significant hibernation population of the species, of over 30 specimens.

For more information on the species, we recommend:

  • Schofield H., Reiter G., Dool S. (2023): Lesser Horseshoe Bat Rhinolophus hipposideros (André, 1797). In: Russo, D. (eds) Chiroptera. Handbook of the Mammals of Europe. Springer, Cham. https://doi.org/10.1007/978-3-030-44029-9_39.
  • Schofield, H.W. (2008) The Lesser Horseshoe Bat Conservation Handbook. Vincent Wildlife Trust.