Stolen bat detector takes summer research data from Forssa

Someone stole a self-recording bat detector from a running trail in Kaikula, an area of Forssa, taking with it nearly a full 200-gigabyte memory card containing recordings collected throughout the summer, Yle reports.

The detector was used in a bat survey commissioned by the city. Environmental manager Niina Salminen-Åberg said the theft was particularly unfortunate because the location had not previously been studied and may be home to bats.

The acoustic recorder is worth no more than 150 euros, depending on the model. Similar devices are commonly used to monitor and study the sounds of bats, birds and other animals.

The stolen device was one of five detectors used in Forssa since around Midsummer. A consultant has also been conducting fieldwork in the evening, making observations and collecting audio recordings.

Survey supports land-use planning

All bat species in Finland are protected, and their presence must be assessed before new construction or renovation work. Forssa carries out bat surveys in cooperation with its land-use planning unit.

Salminen-Åberg said, for example, that a building cannot be renovated if bats have moved in. A derogation permit from the Natural Resources Institute Finland is required if a bat breeding site is destroyed, she said.

A 2018 survey in Forssa found three species: Daubenton’s bat, the northern bat and the whiskered bat. The current survey also covers old Finlayson properties in the city centre, where bats may have roosts.