iBats currently uses time expansion ultrasonic detectors to capture bat echolocation calls along car transects driven by volunteers. The calls are recorded as sound files that are simultaneously spatially referenced with a Global Positioning System (GPS) device. Repeat surveying of identical transects over time produces population trend data that can be used to monitor bat biodiversity and the impact of global change.

Click on the tabs above for details of the equipment we use and our monitoring protocols. Please use the chat boxes on each page if you have comments or suggestions for improvements. We also provide training workshops for interested groups. Please contact us for details.

Specifically, during each car transects a time-expansion bat detector records 320ms 'snapshots' of high frequency sound along the route every 3.5s (approximately). If the car is traveling at 15mph this means that the detector is recording sound every 23.6m (Fig. 1).

Fig. 1. iBats monitoring protocol.

Each route is aboout 40 km which means that each recording contains about one and a half hours of expanded 'snapshots'. In addition to recording high frequency sounds, every 15m a GPS unit records the location (latitude and longitude), altitude and distance from the start into a data file. By comparing the sound track time to the nearest GPS time, the location at which each bat call was heard can be determined.