“Encountering Urban Bats” at the Montpellier-Nîmes School of Medicine

Where is the Molosse hiding?

That is the question chiropterologists—scientists who study bats—are asking themselves. The area around Saint-Pierre Cathedral and the buildings of the former medical school are home to one or more individuals of an unusual species, Cestoni’s Molossus (Tadarida teniotis). Native to tropical regions, Cestoni’s Molossus has adapted to our latitudes and colonized all Mediterranean regions, as well as the Pyrenees and the Alps. This so-called “high-flying” species, which is among the largest bats in France, is most commonly found in cliff areas. However, acoustic monitoring has also confirmed its presence as far as downtown Montpellier, and it is even possible that some individuals have taken refuge on a tall building facade. While all other bat species in France emit inaudible echolocation sounds (ultrasounds above 20 kHz), Cestoni’s Molossus is the only one to emit sounds within the audible range. If you listen carefully, you might be lucky enough to hear its whistle (similar to the call of the song thrush) one hour after sunset.
The areas around buildings are also frequented by the three species of pipistrelle—those tiny bats no bigger than a sugar cube that can usually be seen circling streetlights as soon as the sun sets. Kuhl’s pipistrelle, common pipistrelle, and pygmy pipistrelle are indeed quite common in urban areas. Their highly adaptable ecology allows them to find refuge in hollow trees, cracks in building facades, under roofs, or behind shutters. Some adventurous ones even venture into houses and apartments in late summer. Don’t worry—since they’re insectivores, they won’t attack you. To see them in flight, simply look up at sunset. To hear them, however, you’ll need specialized listening equipment. This is what participants in the “Halloween” discovery tour—organized in partnership with the Montpellier Tourist Office—were able to experience on the grounds and in the inner courtyard of the former School of Medicine. Accompanied by Thierry ALIGNAN (Canopée34) and Alexis BULAND (EGPN student)—both passionate about these small flying mammals—the naturally curious participants were amazed by the sensory experience on offer… Seeing with their ears…
New outings are expected to be organized sometime next spring, as the bats gradually enter hibernation with the approach of winter… Except for Cestoni’s Molossus, which will remain active—albeit to a lesser extent during the coldest weeks—throughout the winter. Keep your ears open—you might be lucky enough to hear it as you stroll after dark between the cathedral and the Jardin des Plantes. tsssssik, tsssssik, tsssssik, tsssssik…
Thierry Alignan
Photo credits: Thierry Alignan, Alexis Buland
Thiseducational program on bats, designed to raise awareness about these animals and dispel myths about them, was carried out in partnership with the Tourist Office to highlight the richness of our heritage and its unique features.

This educational program for those curious about the animal world was led by a specialist (a chiropterologist) who, after a period of discussion and explanation, invited participants to listen to the ultrasonic sounds emitted by bats using sensors that convert them into audible sound.

We will let you know the dates of upcoming themed tours.