Every year in spring the nesting aids are monitored by a team from the Research Institute of Wildlife Ecology of the University of Veterinary Medicine Vienna and BirdLife Austria. From February to May the nesting aids are repeatedly controlled. Not only binoculars and spotting scope are used, but also a remote-controlled drone which directly sends pictures of the nesting aids to the researchers. This device is especially used where the researchers are unsure about the development during the breeding season. This innovative monitoring method is time efficient, safe and up to date it could not be observed that the birds felt disturbed.