An unexpected paradise for bats. In a large herbivore reserve, scientists counted two-thirds of bat species found in the region
This year, scientists recorded a remarkably rich presence of bats in a large herbivore reserve and its closest surroundings at the former military training area of Milovice outside Prague. Since 2015, herds of wild horses, European bison and aurochs produced through a back-breeding programme have been living in the reserve.
As part of a large herbivore return scheme, systematic monitoring was conducted for the first time ever, targeting bats in a territory that so far had been somewhat ignored by scientists investigating these flying mammals. “Monitoring was chiefly carried out using automatic devices recording the echolocation of bats passing by. These are special instruments for recording ultrasound signals used by the mammals as radar to navigate and hunt food,” says Radek K. Lucan from the Department of Zoology of Charles University in Prague, who manages the bat monitoring project.
A total of 15 species were found that the detectors can reliably identify, and three “twin species” that have signals similar enough that the detectors cannot distinguish the two species from each other. “This means that at least 18 species have been shown to be present, which is remarkable since this represents two-thirds of all bat species found in the Czech Republic,” said Miloslav Jirku from the Biological Centre of the Academy of Sciences of the Czech Republic.
In addition to common species, a large number of rather rare but abundant bats have been identified there. The locations provide everything needed, even for forest species with the highest requirements, such as the Leisler’s bat and the Bechstein’s bat. While these find shelter in hollows during the day, they often hunt food on the adjacent steppe at night. Similar to monitoring other groups of local organisms, the research of bats has highlighted an important matter, which is the extraordinary importance of the former military area as a whole. “It is not only the local, well-preserved deciduous woods or just the varied mosaic of different types of meadows and steppes which should be valued. This piece of landscape is extremely helpful for how the local near-natural dry forests combine with forestless zones to form one coherent unit that has no parallel in our country,” notes Miloslav Jirku.
All bat species also benefit from the presence of a number of small pools built locally for rare crustaceans and amphibians. They also play the role of watering sites for all animals irrespective of size, from butterflies to mighty European bison that visit the places. “There are few who associate bats with water, but these creatures need to drink, too. It is the presence of pools in the local very dry setting that is an important element in the landscape and one that is beneficial for the creatures,” says Lucan, pointing to the unusual connection.
In addition, statistical evaluation of data from the recording devices has shown that more bats fly above land grazed by large herbivores compared with areas that are not grazed. Bats can travel many kilometres at night and, thanks to their mobility, can explore large areas of the landscape using their powerful sonar as they search for hunting grounds. This allows them to choose the best areas with ample prey, such as nocturnal lepidopterans and beetles.
“Scientists have already seen incredibly positive results in the past two years, whether it was the monitoring of endangered plants such as cross gentians, which locally have one of the largest populations in the country, or the butterfly census. This means that the surprisingly high presence of rare bats is another confirmation that grazing large herbivores is restoring the former diversity to the landscape,” says Dalibor Dostal, director of the conservation organization European Wildlife.
The rich bat fauna in the former military zone is in sharp contrast to the landscape surrounding the area, where populations of such animals are significantly smaller, since the large herbivore reserve is an “island” with an exceptionally diverse landscape in a uniform “sea” of large-scale farming.
Photo: Radek K. Lucan
