The Anabat system can be used in many different ways, allowing a more flexible approach to bat surveys.
Data can be gathered over a number of months or even years and then analysed in detail to reveal patterns of bat activity over long periods.
Bat surveys using the Anabat system
Bats have evolved over millions of years in a way which has made it difficult for predators to find them. This is good for the survival of bats, but it makes finding bats very difficult for bat surveyors too.
Bat surveyors look for static field signs of bats such as droppings and feeding remains and also signs of wear and staining around potential roost entrances. Bat surveyors will also carry out bat activity surveys during the times of year that bats are active usually the spring and summer months.
During a bat activity survey the surveyors listen for the high frequency echolocation calls of bats using bat detectors. Bat detectors come in many different types but generally speaking they reduce the frequency of sounds so that they can be heard by the human ear. United Environmental Services have been using this type bat detectors for a number of years and they are very effective. The difficulty is that you may only have a split second to hear a sound and then make a decision as to the species of bat that was heard, and importantly what the bat was doing.
For the last year we have been using the Anabat system which scans all frequencies at once, shows a sonogram of the sound in real time, and automatically records the call for later analysis. The fact that the calls can be reviewed later on rather than only in the field means that we can build up a much clearer picture of how bats are using an area. This in turn has meant that we can provide much more detailed information to our clients, and also to the Local Planning Authorities and Licensing Agencies, which makes it easier for them to make decisions on any given project.
The Anabat system can also be left to to record data remotely for months at a time, again providing data that was not before available without great expense.