INTERREG V-A project: protectBats

Identifying local-extinction agents of the lesser horseshoe bat in the Bavarian-Tyrolean Alpine space

The bat species lesser horseshoe bat (Rhinolophus hipposideros) hanging from the woodwork in a nursery roosts, they are classified as "critically endangered" on the Red List in Bavaria and as "endangered" in Austria; Foto: Anton Vorauer

At the size of a thumb, the lesser horseshoe bat (Rhinolophus hipposideros) is among the smallest European bats. It is included in Appendices II and IV of the EUs Flora Fauna Habitat Directive and thus strictly protected. In the second half of the 20th century, the lesser horseshoe bat experienced catastrophic extinctions. In the Bavarian-Tyrolean Alpine space, for example, about half of the 100 known occurrences vanished.

The aim of the protectBats project was to clarify the extent to which environmental chemicals are the cause of the population declines. For this purpose, the current nursery roosts of the lesser horseshoe bat in the Bavarian-Tyrolean Alps were documented and the occurrence of heavy metals and organochlorine pesticides was investigated.

It was shown that the lead concentrations in the bats' feces were significantly increased by a factor of more than 10 at the sites where the bats had disappeared. Cadmium was also found in concentrations three times higher in the extinct colonies than in the surviving colonies.

Lead disrupts the nervous system of mammals, which in bats is reflected in flight and coordination disorders. The substances found were introduced into the environment through the use of lead (more precisely tetraethyl lead) as an anti-knock agent in petrol until the late 1980s, but also through contamination in artificial fertilizers or via residues in old paints. Lead in particular accumulates in living organisms via the food chain and can thus reach harmful concentrations in living organisms.

Besides the heavy metals detected, organochlorine pesticides were also found in the indoor air at the sites investigated. These were mainly lindane, a now banned wood preservative, which also accumulates via the food chain, is very poorly biodegradable and can be harmful to living organisms.

In addition to the findings on the influence of environmental chemicals on the bat population, the project identified habitat loss as a further cause of the decline in bat colonies.

The results of the study were published in Global Ecology and Conservation.

• Clarification of local causes for lesser horseshoe bat extinction in the Bavarian-Tyrolean Alpine region

Project partner

Lead partner was the Leopold-Franzens University of Innsbruck with the Research Group of Molecular Ecology. Project partners from Austria were the Coordination Office for Bat Protection and Research in Austria.

Project partners from Bavaria were the Coordination Office for Bat Protection in Southern Bavaria, the Lower Nature Conservation Authority of the district of Garmisch-Partenkirchen and the Bavarian Environment Agency.

The results of the project are incorporated into further research work at the University of Innsbruck, Chair of Molecular Ecology, and will serve the project partners for long-term bat conservation as a whole.

Funding

The project (TIR 19) was financially supported by the EU programme INTERREG V-A Austria/Bavaria 2014-2020. The project was co-financed by the Leopold-Franzens-University of Innsbruck.

Project management

Leopold-Franzens-University Innsbruck, Chair of Molecular Ecology

Contact

• Schlick-Steiner, Birgit Christiane
• Steiner, Florian Michael
• Röß, Cornelia