Monitoring program for wind farm Jasenice

Project name: Monitoring program for wind farm Jasenice

Client: Vjetropark Jasenice Ltd.
Period: 10/2019 – 04/2022
Location: Croatia


Monitoring of ornithofauna and bat fauna at wind farm Jasenice was carried out over two years (2020 and 2021) during the operation of the wind farm.

The Ornithofauna monitoring program was carried out in accordance with the Environmental Impact Assessment (EIA) Decision of the Ministry of Environmental Protection and Physical Planning on the Acceptability of the project to the environment for wind farm Jasenice (Class: UP/I-351-02/00-06/0067, Reg. No.: 531-05/1-VM-01-9, dated 6th July 2001).

The following activities were performed as part of ornithofauna monitoring:

  • Monitoring of raptor bird activity using Vantage Point survey
  • Monitoring of local breeding bird communities using a linear transect
  • Monitoring of nocturnal birds
  • Non-standardized methodology
  • Search for dead/injured birds
  • Searcher efficiency and carcass persistence trials
  • Preparation of Mission reports
  • Processing and analysis of results: spatial (GIS) analysis of flight movements of raptors,
    assessment of the number of breeding pairs, statistical analysis of bird mortality
  • impact assessment on birds for wind farm Jasenice
  • communication and consultations with the Client
  • Preparation of an Annual report and a Final report.

The impact of the wind farm on birds was monitored by observing birds from a Vantage Point next to each wind turbine, recording breeding birds along a linear transect, recoding nocturnal birds using methods of listening and playback of bird calls, and searching for dead/injured birds around wind turbines to determine casualties. The non-standardized methodology was carried out to get a wider picture of bird community structure which could not be obtained with other methods.

The direction and height of flight movements of raptors in relation to the wind turbines were analysed. The number of breeding pairs was estimated using data from the line transect and monitoring of nocturnal species of birds. The bird carcasses were examined and identified, and their position in relation to the wind turbines was analysed in GIS. Carcass persistence and searcher efficiency were assessed using the GenEst tool. The impact on mortality was not assessed as significant, but potential avoidance of the wind farm area by some species was noted. The monitoring methodology, results and analyses were presented in the reports.

The following activities were performed as part of bat monitoring:

  • Periodic bat call recording on a transect route
  • Periodic bat call recording on a stationary location
  • Searching for bat fatalities
  • Searcher efficiency and carcass persistence trials
  • Visual observing of bats
  • Preparation of Mission reports
  • Processing and analysis of results: sonogram analysis, analysis of microclimatic conditions, spatial (GIS) analysis of bat activity, spatial (GIS) analysis of bat carcasses, statistical analysis of bat mortality
  • Impact assessment on bats for wind farm Jasenice
  • Communication and consultations with the Client
  • Proposal of mitigation measures for bats
  • Preparation of an Annual report and a Final report.

The impact of the wind farm on bats was monitored by determining bat activity around each wind turbine using walked bat detector surveys along a transect route, by recording bat calls on a stationary location to determine their activity throughout the night, by searching for bat carcasses around wind turbines to determine casualties, and occasionally by visual observing bats in the wider area of the wind farm using a thermal imaging camera.

Sonograms from the bat calls recording were analysed in the BatExplorer software with the help of literature. Bat activity was analysed temporally, spatially, and in relation to microclimatic conditions. The bat carcasses were examined and identified, and their position in relation to the wind turbines was analysed in GIS. The number of bat carcasses
was corrected with carcass persistence, searcher efficiency, and the proportion of searched area and carcass distance from wind turbines using the GenEst tool and GIS.

Based on the analysis of the results significance of casualties was assessed and mitigation measures were proposed. The monitoring methodology, results, analyses and recommendations were presented in the reports.

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