Bats and the importance of old forest patches in the fragmented Central European landscape
In the fragmented Central European landscape, old forest is a scarce habitat. The patches of old forests that exist in the production landscape outside of protected areas are at risk of being logged for timber. At the same time, these habitats can serve as important refuges to support biodiversity, especially for species dependent on old trees and tree characteristics developed with age. In my research as a Ph.D. student at the Forest Ecology department at the Czech University of Life Sciences in Prague, I will specifically work with the importance of these habitats for the conservation of bats. A network of research plots has been established over the whole Czech Republic and on these plots, I will record bats using sound recorders capable of recording ultrasounds. The recorders will be put up in the summer when bats are active and emit sounds to navigate when they are hunting.
Bats are active at night and navigate using ultrasonic signals with too high frequencies for the human ear to hear. During the light hours of the day, bats hide in roosting places. Hence, although many bat species live close to us (maybe even in your house) much is still unknown about these cryptic animals. Bat roosts can be found in trees with suitable structures or in urban areas such as in churches or attics. Different bat species prefer different roosting sites, but we know that trees are crucial for some of the species as places to rest and for breeding. In the summer the female bats with their yearly cubs gather in colonies, located for example inside a tree hollow. Feeding the cubs demands a lot of energy from the female bats and several times during the night they must return to the colony to nurse the young. Hence, female bats are dependent on the landscape in the vicinity of their roost, which should provide good commuting routes and foraging places with a lot of insects. For some bat species, the forest is important for hunting insects, while other species use more open spaces, rely on edges, or hunt by ponds or streams.
Hence, forests constitute an important habitat for many species either as a place to rest, bring up cubs, or find food. Suitable tree characteristics for roosting, such as hollows, cracks, and loose bark are often lacking in the young production forest. Therefore, it is important that we increase our knowledge of how bats use old forests and the role of these habitats in supporting bat diversity in a fragmented landscape.
