Читать книгу Practical Field Ecology - C. Philip Wheater - Страница 25

Of the 18 species of bat recorded in the UK, 14 are known to roost in trees (Bat Tree Habitat Key Project 2018). Little is known about inter or intraspecific differences in the use of tree features for roosting, or the extent to which different species use trees in different habitats or during different seasons. To fill this gap in our knowledge, the BTHK project collects and analyses records of tree roosting behaviour submitted by bat researchers, ecological consultants, arboriculturalists, and bat conservation workers. One problem identified by the BTHK project is the inadequacy of current methods to sample bats roosting in trees. Endoscopes are frequently used but provide limited data, because it is very difficult to identify bats to species level using this method (let alone record sex ratios!). Furthermore, bats frequently cluster in narrow crevices, making observation of more than one or two bats almost impossible. An alternative method involves sampling bats with a handheld net as they exit the roost, but no safe, reliable, purpose‐built net existed.