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Automatic presence-absence telemetry of bats in the intrusion area

Manual telemetry – a bottleneck for the expansion of wind power

  • In order to reduce dependence on fossil fuels to a minimum, countries around the world must radically accelerate the expansion of wind energy.
  • This will result in conflicts with European and international species protection legislation. Essential hunting grounds and roosts of forest-dwelling bat species must not be disturbed.
  • Manual radio telemetry to determine the risk potential is extremely time-consuming, labor-intensive and costly and the results are inaccurate; deviations of up to 200 meters with a 5° angle error.
  • The lack of personnel capacity in the expert offices carrying out the work poses the risk of becoming a bottleneck in the expansion of wind power.

The solution – Automatic monitoring of bat movement

  • A method for the automatic recording and real-time transmission of VHF transmitter signals was developed at the Philipps University of Marburg.
  • In close cooperation with expert offices (BFL, IFU) and various project planners, the method was adapted for recording in intervention projects.
  • It has completely replaced manual telemetry in 15 wind power projects in Rhineland-Palatinate and Hesse over the last 3 years.
Figure 1: Live view of bat activity in the tRackIT online system of a Bechstein’s bat (Mbec), a fringed bat (Mnat) and a brown long-eared bat (Paur).

The method – Automated monitoring

  • Bat roosts or essential hunting areas are protected by distance requirements.
  • Transmitter signal strength and distance (up to 1,000m) are correlated using statistical methods (Fig. 2) to determine the distance of hunting areas (Fig. 3) and roosts (Fig. 4) from the planned intervention site.
  • The measurement error averages 30 m and is therefore significantly lower than with manual telemetry.
  • At least 40 transmittered individuals can be recorded simultaneously and over the entire transmitter runtime without the need for personnel.
  • The data received is transmitted to a server in real time and visualized (Fig. 1). Automatic reports are generated at the end of the recording season.
Figure 2: Ratio of signal strength (X) to distance (Y) measured with a tRackIT station.

The advantages – quality, transparency and efficiency

  • Significant reduction in workload, allowing more survey areas per season to be systematically and reproducibly examined.
  • High transparency and reduction of quality fluctuations through standardization; comprehensive and reliable data set; increased legal certainty of expert opinions.
  • Differentiated, detailed and therefore precise nature and species conservation risk assessments.
  • Massive reduction in personnel and costs: 500 person hours per bat colony compared to a few hours installing the stations.
  • Early detection of planning obstacles; prompt adaptation of the planning process; site optimization
  • Reduction in the time between data collection and reporting; competitive advantage for users.
Figure 4: Distance measurements over several days and actual distance to roosts (dots).


Please contact us directly if you are interested in the method and for further information:

Jannis Gottwald
+49 1578 3538221