Avoidance Behaviour of Migrating Raptors Approaching an Offshore Wind Farm

  • Erik Mandrup JacobsenEmail author
  • Flemming Pagh Jensen
  • Jan Blew


During three seasons, we studied avoidance behaviour of migrating raptors when approaching an offshore wind farm in northern Baltic Sea 20 km from the coast.

From a substation 1.8 km west of the wind farm, we recorded macro, meso and micro avoidance behaviour of individual raptors approaching the wind farm, using a pre-defined protocol. We defined macro avoidance as when the raptor completely avoids entering the wind farm, meso avoidance as a significant change in altitude or direction before arrival and micro avoidance as a sudden change of flight when passing a turbine at close range.

In total, 466 migrating raptors representing 13 species were observed of which 73% representing 9 species showed macro, meso and/or micro avoidance behaviour.

Macro avoidance was recorded among ten of the species including 59% of red kites, 46% of common kestrels, 42% of sparrowhawks and 30% of honey buzzards. Three quarters of these raptors subsequently left the AOWF in a westerly direction, indicating that they returned to the mainland. The remaining birds flew either north or south parallel to the first row of turbines, suggesting they tried to navigate around the wind farm.

Our study demonstrated a barrier effect from the offshore wind farm influencing the migration of raptors by forcing some birds to use alternative and potentially more risky sea crossings. This may potentially affect survival and fitness of individuals and populations. Accordingly, we recommend that the location of important raptor migration routes is taken into consideration in siting of future offshore wind farms.


Bird migration Macro, meso and micro avoidance Behavioural response Barrier effect 



The post-construction monitoring study at the AOWF was financed by Ørsted, Denmark (Previously DONG Energy). The photo was kindly provided by Lars Maltha Rasmussen.


  1. 1.
    Colmenar-Santos, A., Perera-Perez, J., Borge-Diez, D., de Palacio-Rodríguez, C.: Offshore wind energy: a review of the current status, challenges and future development in Spain. Renew. Sustain. Energy Rev. 64, 1–18. Elsevier (2016)CrossRefGoogle Scholar
  2. 2.
    Drewitt, A.L., Langston, R.H.W.: Assessing the impacts of wind farms on birds. Ibis. 148, 29–42 (2006)CrossRefGoogle Scholar
  3. 3.
    Humphreys, E.M., Cook, A.S.C.P., Burton, N.H.K.: Collision, Displacement and Barrier Effect Concept Note BTO Research Report No. 669. The British Trust for Ornithology, The Nunnery, Thetford (2015)Google Scholar
  4. 4.
    Kuvlesky, W.P., Brennan, L.A., Morrison, M.L., Boydston, K.K., Ballard, B.M., Bryant, F.C.: Wind energy development and wildlife conservation: challenges and opportunities. J. Wildl. Manag. 71, 2487–2498 (2007)CrossRefGoogle Scholar
  5. 5.
    Stewart, G.B., Pullin, A.S., Coles, C.F.: Poor evidence-base for assessment of windfarm impacts on birds. Environ. Conserv. 34, 1–11 (2007)CrossRefGoogle Scholar
  6. 6.
    Rydell, J., Engström, H., Hedenström, A., Kyed Larsen, J., Pettersson, J., Green, M.: The Effect of Wind Power on Birds and Bats – A Synthesis, 152 pp. Swedish Environmental Protection Agency, Stockholm (2012)Google Scholar
  7. 7.
    Orloff, S., Flannery, A.: Wind turbine effects on avian activity, habitat use and mortality in Altamont Pass and Solano County wind resource areas, 1989–1991. Unpublished final report prepared by BioSystems Analysis Inc., Tiburon, California, for the California Energy Commission, Sacramento, grant 990-89-003. 199 p (1992)Google Scholar
  8. 8.
    Smallwood, K.S., Thelander, C.: Bird mortality in the Altamont Pass Wind Resource Area, California. J. Wildl. Manag. 72, 215–223 (2008)CrossRefGoogle Scholar
  9. 9.
    Carrete, M., Sanches-Zapata, J.A., Benitez, J.R., Lobon, M., Donazar, J.A.: Large scale risk-assessment of wind-farms on population viability of a globally endangered raptor. Biol. Conserv. 142, 2954–2961 (2009)CrossRefGoogle Scholar
  10. 10.
    Alerstam, T.: Analysis and theory of visible bird migration. Oikos. 30, 273–349 (1978). CrossRefGoogle Scholar
  11. 11.
    Newton, I.: Bird Migration. Collins, London (2010)Google Scholar
  12. 12.
    Alerstam, T.: Bird Migration. Cambridge University Press, Cambridge (1990)Google Scholar
  13. 13.
    Masden, E.A., Hayden, D.T., Fox, A.D., Furness, R.W., Bullman, R., Desholm, M.: Barriers to movement: impacts of wind farms on migrating birds. J. Mar. Sci. 66, 746–753 (2009)Google Scholar
  14. 14.
    BirdLife International, Denmark. Homepage, Last accessed 28 Mar 2018
  15. 15.
    Krijgsveld, K.L.: Avoidance behaviour of birds around offshore wind farms. Overview of knowledge including effects of configuration. Bureau Waardenburg bv. 35 pp (2014)Google Scholar
  16. 16.
    Garvin, J.C., Jennelle, C.S., Drake, D., Grodsky, S.M.: Response of raptors to a windfarm. J. Appl. Ecol. 48, 199–209 (2011)CrossRefGoogle Scholar
  17. 17.
    Villegas-Patraca, R., Cabrera-Cruz, S.A., Herrera-Alsina: Soaring migratory birds avoid wind farm in the Isthmus of Tehuantepec, Southern Mexico. PLoS ONE. 9(3), e92462 (2014). CrossRefGoogle Scholar
  18. 18.
    Cabrera-Cruz, S.A., Villegas-Patraca, R.: Response of migrating raptors to an increasing number of wind farms. J. Appl. Ecol. 53, 1667–1675 (2016)CrossRefGoogle Scholar
  19. 19.
    Skov, H., Desholm, M., Heinänen, S., Kahlert, J.A., Laubek, B., Jensen, N.E., Zydelis, R., Jensen, B.P.: Patterns of migrating soaring migrants indicate attraction to marine wind farms. Biol. Lett. 12, 20160804 (2017). CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Erik Mandrup Jacobsen
    • 1
    Email author
  • Flemming Pagh Jensen
    • 1
  • Jan Blew
    • 2
  1. 1.Orbicon A/STaastrupDenmark
  2. 2.BioConsult SH GmbH & Co. KGHusumGermany

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