Bird and Bat Monitoring and Wind Farm Interaction with Natura 2000 Ecological Network Assessment for Opor Wind Farm

Project name: Environmental Studies for the Pre-Construction Phase of Opor Wind Farm (Bird and Bat Monitoring and Wind Farm Interaction with Natura 2000 Ecological Network Assessment)

Client: Opor Wind Farm / Acciona Energija Ltd.

Project partners: Supernatural Ltd.
Period: 08/2022 – 07/2024
Location: Croatia


Field activities for bat and ornithofauna monitoring for Opor Wind Farm were conducted from August 2022 to August 2023.

The following activities were performed as part of bat monitoring:

  • periodic bat call recording along a transect route
  • continuous bat call recording at a stationary point
  • roost site surveys
  • mission report preparation
  • data processing and analysis
  • impact assessment on bats
  • communication and consultation with the client
  • final report on bat fauna
  • final report on target bat species of Natura 2000.

The following activities were performed as part of ornithofauna monitoring:

  • monitoring from observation points (Vantage point methodology)
  • transmission line surveys
  • raptor nest searches
  • transect surveys for nesting birds (songbird fauna monitoring)
  • nocturnal bird call surveys (owl monitoring)
  • mission report preparation
  • data processing and analysis
  • impact assessment on birds
  • communication and consultation with the client
  • final report on ornithofauna
  • final report on target bird species of Natura 2000.

Bat fauna was monitored by recording bat calls at a stationary point and along a transect route to assess activity levels and by surveying nearby important roosting sites. Bat call recordings were analyzed using BatExplorer software and relevant literature. Bat activity was analyzed temporally and spatially within a GIS environment to create a map of presumed space use degree (SUD). Based on these analyses, potential impacts of the project on bat fauna were assessed, and mitigation measures were proposed. The monitoring methodology, results, analyses, and recommendations were presented in the final report. Potential impacts on target bat species of Natura 2000 were analyzed in greater detail and presented in a separate report.

Ornithofauna was monitored through observations from vantage points, casualty searches under an existing transmission line, raptor nest searches, transect surveys for nesting birds, and call surveys for nocturnal birds. Overflights of species susceptible to wind turbine collisions were analyzed within a GIS environment, and collision risk was calculated using the Collision Risk Model (CRM). Nesting pair density and the number of pairs of nocturnal species were calculated. Based on these analyses, potential impacts of the project on ornithofauna were assessed, and mitigation measures were proposed. The monitoring methodology, results, analyses, and recommendations were presented in the final report. Potential impacts on target bird species of Natura 2000 were analyzed in greater detail and presented in a separate report.

The interaction of Opor Wind Farm with Natura 2000 was assessed, including potential impacts on target bird, bat, insect, reptile, and plant species, as well as target habitat types. Mitigation measures and monitoring programs were proposed in a report.

Implementation of this Project contributes to the following Sustainable Development Goals:

Oikon d.o.o.
Oikon d.o.o.