Bats are monitored through a variety of methods. In the winter, hibernating bats are counted in their hibernation sites, and in the summer, information on the distribution of bats can be collected through acoustic surveying. Ultrasonic detectors, also known as bat detectors, are used in monitoring during the summer. Detectors have to be used because the ultrasonic sound emitted by bats exceeds the human hearing range. Surveys can be active, conducted by observers in the field, or passive, conducted with the help of technical devices left in the field. The collected acoustic material provides observation data about the activity of bats and any changes in it, but does not indicate the number of individuals monitored. Long-term observation helps in detecting changes in the distribution of species. You can volunteer for summertime bat monitoring.
In this form of monitoring, hibernating bats are counted in their hibernation sites to obtain data on changes in species distribution and population. Suitable sites include caves, cellars, and underground structures of different kinds where conditions remain cool and humid throughout the winter. Many bats spend their winter in places that are hard or impossible to detect. As bats must not be disturbed, the census must be done quickly. For a long time, monitoring has been conducted in the same locations in South-East Finland with some hundred sites inspected every year. Because the bat census requires species recognition skills, experienced volunteers usually participate in the project.
Data on the distribution and activity of bat species are collected throughout the summer by using continuous acoustic monitoring methods in collaboration with the research stations of Finnish universities. Ten research stations or other surveying locations across Finland are participating in the monitoring. The research stations are responsible for maintaining the sound recorders placed in the field to collect data.
The distribution of bat species and changes in their populations are investigated through monitoring conducted by volunteers with the help of small sound recorders left in the field for certain periods during the summer. The volunteers obtain the recorders from the Finnish Museum of Natural History, which also processes the data collected. The aim is to collect data comprehensively from all parts of Finland.
Capturing and ringing bats requires a permit and is usually related to research or surveying projects. Individually marked animals provide information on their age, movements and site fidelity. The number of ringed bats is considerably lower than that of ringed birds. Annually, fewer than 250 individuals are ringed, and the total number of bats ringed since 2004 is just over 5,200.
You can become a bat ringer by completing a test, practising to handle bats under the supervision of an experienced ringer and drafting a research plan about the ringing project to be attached to the permit application submitted to the ELY Centre. All bat ringers must also have a valid rabies vaccination.
Ringing tests are arranged every year according to need.
If you are planning to be become a bat ringer, contact the planning officer in charge of the coordination of bat monitoring and ringing.