“It’s still a bit scary, but it’s okay”: meeting the bats at nightfall in the Sare caves

As part of the Rendez-vous nature du 64, on Tuesday, August 26, a select few were able to visit the Sare caves at night. A dive into the mysteries of the Schreibers' bat, a species of bat endemic to the department.

The sky is low, the weather rainy, and the light gloomy. An almost mystical atmosphere settles around the Sare caves. Perfect conditions for diving into the depths of the earth this Tuesday, August 26. That evening, the caves offer a small group of visitors the opportunity to experience a unique experience. They set off to meet the Schreiber's bat, a species of bat endemic to the department.

The visit begins on time for the 20 privileged evening guests, with the screening of a film made in the heart of the Espalungue cave, in Béarn, to study the mammal's behavior up close.

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On site, mostly families came with children. This is the case for Imanol, a biology teacher at Saint-Vincent in Hendaye. He made the trip with his two children, Anton and Alice, ages 5 and 8, to give them a little break from their vacation. As for the little ones, the outing is approved. "We already came last Thursday, but I wanted to see even more bats," Anton confides cheerfully.

Visitors are in good hands: Imanol Amestoy of the Basque Coastal CPIE, Peio Cornu, and Denis Vincent of the Conservatoire des espèces naturelles (CEN) lead the evening tour. As part of the "Priority Cave Bat in New Aquitaine" research program, funded by the Region, the Sare site is important to CEN members. "We use it as a tagging site to monitor species movements, along with 10 other sites elsewhere in the region," notes Denis Vincent. "It's an essential area for analysis."

The Sare caves thus play a dual role, both as a protection center and a true research laboratory.

Everyone is waiting for the first flap of the wings, the first shadow to appear on the rock.

Around 8:15 p.m., the long-awaited moment arrives. Step by step, the group approaches the cave. Under the large porch, which rises 50 meters high, the procession leaves the daylight to plunge into the shadows of the limestone rock. Inside, the perception of time seems different. The drops hitting the ground, the coldness, the noises—everyone's sense seems heightened. The children, impatient, stamp their feet: "It's still a little scary, but it's okay," whispers Anton. Everyone waits for the first flap of wings, the first shadow to appear on the rock.

Suddenly, a dark flash pierces the vault. Exclamations ring out in the gloom: "Look up there, there's loads of them," Alice whispers to her little brother.

Young and old alike are transported into this underground interlude, as the first miniopters take flight into the cave. You have to be attentive, as the scene is brief.

The species is sometimes very mobile, within the cave itself, or even further afield, says Peio. "By microchipping some individuals, we were able to identify a minioptera one evening in Sare, and the next day it was in Arudy. Hence the importance of sharing these sites for research," he explains.

Across France, the number of Schreibers's bats is declining, but the Sare Cave is an exception. "The number of individuals present has been stable for about fifteen years," smiles Denis. After the 2003 epidemic that wiped out half of the species in France, nearly 500 bats still inhabit the area.

The colony is very active, as it did not expect to see people at this time.

This late August evening, the bats are less shy than usual. "They've figured out the usual end-of-visit schedule. The colony is very active because they weren't expecting to see people at this time," smiles Peio.

Imanol Amestoy of the CPIE pulls an intriguing little box from his bag. He barely turns it on when a strange crackling sound fills the air. It's a "bat-box," a device capable of translating the ultrasound emitted by bats into sounds perceptible to the human ear. The children concentrate, fascinated by this invisible music.

Around 9:30 p.m., the group leaves the cave, the sun having had time to set. The bats are getting ready to come out for their nighttime hunting season. Listening to them, young Anton and Alice are almost coming back a third time, under the amazed gaze of their father. "I'm happy to bring them here. The proposed initiative is purely family-oriented, we're all happy," he says with a smile.

"I think tonight's goal was achieved," Peio said after the visit. "To raise awareness about this little-understood, sometimes unloved species, so that knowledge can remove preconceptions."

Other meetings are planned before the end of the year, to continue discovering the endemic species of the department.