Bats targeted by the project are among the most endangered in Poland and in the whole of Europe. Their survival depends on the durability of winter hiding places, where hibernating they wait out the most difficult period of the year and summer roosts, in which females give birth to their young. It is also important that the habitats around these shelters meet very specific conditions in line with the needs of bats. Adverse changes in the vicinity of the colony can affect the success and survival of the entire local bat population. Monitoring the situation allows for a quick response and, if necessary, for a smooth improvement of the habitat.

Monitoring covered almost all Polish sites of the lesser horseshoe bat, Geoffroy’s bat and selected roosts of the greater mouse-eared bat. In June and July 2022, the project team checked 122 breeding colonies. All of them were in buildings. All encountered bats were counted, a total of nearly 20,000 individuals from 9 species.

In many sites, the monitoring team found various threats to the bats living there. All information has been carefully recorded and the most urgent and important cases will be mended by intervention. In several cases, the team reacted immediately, e.g. by removing nets blocking bats from entering the building. Of course, all activities were carried out in consultation with the hosts of the facilities. It was an opportunity to explain to them how bats use the building and what the problem was.

The recommended works and protective measures included renovating the roof or building, optimizing the use of space within the attic, improving habitat condition by modifying natural and artificial lighting, adjusting and diversifying the temperature in different parts of the facility, providing grip support, entrance and exit opportunities, while preventing access to the attic for birds. Improving the safety of bats and humans will also require the removal of accumulated guano from 24 attics, sometimes protecting floors with foil. In 9 facilities, you will need to care for trees around the building or plant new ones. In 23 facilities, works are planned, on which it will be necessary to consult them on an ongoing basis. In several facilities, it is reasonable to improve access and safety during monitoring.