Bats in Montpellier

Montpellier is one of the cities in mainland France with the highest diversity of bat species. There are 17 species present out of the 35 species recorded throughout mainland France.

17 bat species recorded

These data are the result of a study carried out in 2011 as part of the Muséum national d'histoire naturelle's "Vigie Nature" program. The operation mobilized a wide range of players: the Ecologistes de l'Euzière, the Groupe Chiroptère Languedoc-Roussillon, Montpellier's municipal services (green spaces and Lunaret zoo), as well as volunteer citizens.

21 green spaces spread throughout the commune were monitored using recording devices (bat boxes) installed in the parks.

72 additional listening points were set up in neighborhood green spaces and a further 13 from the balconies of participating volunteers.

Two key waterways

The abundance of data collected has confirmed that Montpellier is among France's most bat-friendly cities. The green spaces most frequented by these flying mammals are characterized by their large surface area and proximity to the Mosson and Lez rivers. Indeed, these 2 watercourses constitute vital corridors for numerous animal species, including bats, and offer them privileged hunting areas.

Other factors also contribute to the remarkable presence of bats in Montpellier: the low human presence in certain sites, the proximity of large buildings and the presence of trees with cavities likely to serve as a refuge for them.

• In autumn, mating takes place. Males and females gather in the same roost. It's also a time of intense hunting, in preparation for the harsh winter months ahead. At the end of autumn, they start looking for a place to hibernate.
• In winter, in the south of France, bats hibernate. Males and females generally hibernate in separate roosts. Females store sperm in a pouch near the ovum, waiting for favorable conditions to initiate embryo development. If their lethargy is disturbed (heat, cold, disturbance), they may move to another site. However, their chances of survival are then threatened by the depletion of their reserves of "brown fat" made in the autumn, and the possibility of finding no other shelter to spend the winter.
• In spring, females look for a well-exposed roost to be warmed by the sun. They give birth together to one or two hairless young, and organize themselves collectively for guarding during hunting times.
• In summer, the young are self-sufficient and can in turn participate in this cycle, although the survival rate of juveniles in the first year is only 50%.

These valuable insectivores are threatened by the destruction of their habitats and the excessive use of pesticides. Fortunately, simple management measures can be put in place to protect them:

• Maintain open and wooded environments, which are favorable to bats. They need these spaces to feed and hunt. It is therefore important to preserve meadows, forests and wetlands.
• Preserve their roosts (old trees, cavities, caves, old buildings, attics...)
• Limit outdoor night lightingas artificial lighting can disrupt bats' orientation and hunting. The Metropole has committed to a policy of sustainable design and management of public lighting with a Light Plan.
• Installing roosts, nesting boxes for bats in gardens, parks, forests and on buildings. This makes up for the lack of natural roosts and provides shelter for bats.

1. Little Rhinolophus Rhinolophus hipposideros - Family Rhinolophidae

This family comprises a single genus (Rhinolophus) characterized by a nasal leaflet through which ultrasound is emitted. Their posture is also typical, as they are systematically suspended by the legs, and at rest, their wings more or less envelop their bodies. Of the 4 French species, 2 are present in Montpellier.

The Petit Rhinolophe has been recorded on the banks of the Mosson, the Grand Rhinolophe in the Réserve du Lez, and both species are present in the Parc Méric. Declining availability of roosting sites is having a major impact on these highly vulnerable animals, as is night-time urban lighting.

2. Murins Myotis sp.- Family Vespertilionidae

The genus Murin Myotis comprises 13 species identified throughout France, including 5 recorded in Montpellier. It is characterized by the absence of complex folds on the snout, and by the contrast in color between the back and belly.

The Large Murin group includes 2 species that are very similar both morphologically and ecologically: the Great Murin and the Little Murin. These are Europe's largest murins, with a wingspan of 35 to 40 cm, weighing around 20 grams. They are among the only bats that hunt almost exclusively in open environments (meadows, dry grasslands, scrubland, etc.) less than 1m above the ground. Their prey are mainly terrestrial insects (beetles, grasshoppers, locusts, etc.). Their winter roosts are exclusively cavernous (caves, mines etc...) for both species.

3. Schreibers' Miniopterus schreibersii - Family Miniopterridae

This family also has only one species in our country, the Schreibers' Miniopter (Miniopterus schreibersii), whose distribution is essentially southern. This medium-sized species has a typical silhouette with long, slender wings, enabling it to fly rapidly at speeds of up to 60km/h. It prefers overcast landscapes, as it is strictly cavernicolous.

During the inventory phases, one individual was recorded hunting on the Place de la Comédie. As only a few dozen cavities are occupied by large colonies of miniopterans in France, our region has a vital role to play in the conservation of this species.