Skip to main content Accessibility help

Power line routing and configuration as major drivers of collision risk in two bustard species

  • Ana Teresa Marques (a1), Ricardo C. Martins (a2), João Paulo Silva (a2), Jorge M. Palmeirim (a1) and Francisco Moreira (a2)...


Collision with power lines is a major cause of mortality for many bird species. Understanding the biotic and abiotic factors that increase collision risk is therefore important for implementing mitigation measures to minimize mortality, such as power line rerouting or wire marking. Here, we used collision events registered during 2003–2015 along 280 km of transmission power lines in southern Portugal to analyse spatio-temporal patterns and collision risk factors in two sympatric, threatened, and collision-prone species: the great bustard Otis tarda and the little bustard Tetrax tetrax. The occurrence of collisions was not uniform across space and time, and variations could be explained by the species' ecological requirements, distribution patterns and behaviour. Although both species fly considerable distances between areas of suitable habitat, collisions were far more likely in power line sections with > 20% (for the little bustard) or > 50% (for the great bustard) of open farmland habitat in the surroundings. Power line configuration was also important: taller pylons and those with a higher number of wire levels posed a higher risk for both species. Wire marking had a small but significant effect for the little bustard, reducing collisions risk. There was, however, no similar effect for the great bustard, possibly a result of limited data. Mitigation measures should be implemented to prevent bustard collisions, including adequate route planning, ideally avoiding areas with > 20% of open habitat. Line configuration and wire marking are particularly important where such localities cannot be avoided and power lines cross areas with a high proportion of bustard habitat, including outside protected areas.


Corresponding author

Corresponding author, E-mail


Hide All

Also at: Centro de Investigação em Biodiversidade e Recursos Genéticos, Laboratório Associado, Universidade do Porto, Vairão, Portugal

Supplementary material for this article is available at



Hide All
Alonso, H., Correia, R.A., Marques, A.T., Palmeirim, J.M., Moreira, F. & Silva, J.P. (2019) Male post-breeding movements and stopover habitat selection of an endangered short-distance migrant, the little bustard Tetrax tetrax. Ibis, published online 12 January 2019.
Barrientos, R., Ponce, C., Palacín, C., Martín, C.A., Martín, B. & Alonso, J.C. (2012) Wire marking results in a small but significant reduction in avian mortality at power lines: a BACI designed study. PLOS ONE, 7, e32569.
Bernardino, J., Bevanger, K., Barrientos, R., Dwyer, J.F., Marques, A.T., Martins, R.C. et al. (2018) Bird collisions with power lines: state of the art and priority areas for research. Biological Conservation, 222, 113.
Bevanger, K. (1998) Biological and conservation aspects of bird mortality caused by electricity power lines: a review. Biological Conservation, 86, 6776.
BirdLife International (2017) IUCN Red List for Birds. [accessed 15 December 2017].
Bjørnstad, O.N. (2016) ncf: Spatial Nonparametric Covariance Functions. R package version 1.1–7. The Comprehensive R Archive Network. [accessed 19 July 2019].
Bjørnstad, O.N. & Falck, W. (2001) Nonparametric spatial covariance functions: estimation and testing. Environmental and Ecological Statistics, 8, 5370.
Burnside, R.J., Collar, N.J., Koshkin, M.A. & Dolman, P.M. (2015) Avian powerline mortalities, including Asian houbara Chlamydotis macqueenii, on the Central Asian flyway in Uzbekistan. Sandgrouse, 37, 161168.
Buston, P.M. & Elith, J. (2011) Determinants of reproductive success in dominant pairs of clownfish: a boosted regression tree analysis. Journal of Animal Ecology, 80, 528538.
De'Ath, G. (2007) Boosted trees for ecological modeling and prediction. Ecology, 88, 243251.
De'Ath, G. & Fabricius, K.E. (2000) Classification and regression trees: a powerful yet simple technique for ecological data analysis. Ecology, 81, 31783192.
DGT (Direção-Geral do Território) (2007) COS 2007—Carta de Ocupação do Solo 2007 para Portugal Continental. Direção-Geral do Território, Lisbon, Portugal.
DGT (Direção-Geral do Território) (2014) Uso e Ocupação do Solo em Portugal Continental. Avaliação e Cenário Futuros, Lisbon, Portugal.
Drewitt, A.L. & Langston, R.H.W. (2008) Collision effects of wind-power generators and other obstacles on birds. Annals of the New York Academy of Sciences, 1134, 233266.
Elith, J., Leathwick, J.R. & Hastie, T. (2008) A working guide to boosted regression trees. Journal of Animal Ecology, 77, 802813.
Equipa Atlas (2008) Atlas das Aves Nidificantes em Portugal (1999–2005). Instituto da Conservaçăo da Natureza e da Biodiversidade, Sociedade Portuguesa para o Estudo das Aves, Parque Natural da Madeira e Secretaria Regional do Ambiente e do Mar, Lisbon, Portugal.
Fernandes, P.M., Monteiro-Henriques, T., Guiomar, N., Loureiro, C. & Barros, A.M.G. (2016) Bottom-up variables govern large-fire size in Portugal. Ecosystems, 19, 13621375.
García de la Morena, E.L., Morales, M.B., Bota, G., Silva, J.P., Ponjoan, A., Suárez, F. et al. (2015) Migration patterns of Iberian little bustards Tetrax tetrax. Ardeola, 62, 95112.
García de la Morena, E., Bota, G., Mañosa, S. & Morales, M. (2017) II Censo Nacional de sisón común: el dramático declive del bastión europeo de la especie. Boletín de Seguimiento de Aves de SEO/BirdLife, 2016, 30–33.
Hijmans, R.J., Phillips, S., Leathwick, J. & Elith, J. (2016) dismo: Species Distribution Modeling. R package version 1. The Comprehensive R Archive Network.
INE (2011) Recenseamento Agrícola 2009—Análise dos Principais Resultados. Instituto Nacional de Estatística, Lisbon, Portugal.
Iñigo, A. & Barov, B. (2010) Action Plan for the Little Bustard Tetrax tetrax in the European Union. SEO/BirdLife and BirdLife International for the European Commission, Cambridge, UK.
Janss, G.F. & Ferrer, M. (1998) Rate of bird collision with power lines: effects of conductor-marking and static wire-marking. Journal of Field Ornithology, 69, 817.
Janss, G.F. & Ferrer, M. (2000) Common crane and great bustard collision with power lines: collision rate and risk exposure. Wildlife Society Bulletin, 28, 675680.
Janss, G.F.E. (2000) Avian mortality from power lines: a morphologic approach of a species-specific mortality. Biological Conservation, 95, 353359.
Jenkins, A.R., Smallie, J.J. & Diamond, M. (2010) Avian collisions with power lines: a global review of causes and mitigation with a South African perspective. Bird Conservation International, 20, 263278.
Jorda, H., Bechtold, M., Jarvis, N. & Koestel, J. (2015) Using boosted regression trees to explore key factors controlling saturated and near-saturated hydraulic conductivity. European Journal of Soil Science, 66, 744756.
Leathwick, J., Elith, J., Francis, M., Hastie, T. & Taylor, P. (2006) Variation in demersal fish species richness in the oceans surrounding New Zealand: an analysis using boosted regression trees. Marine Ecology Progress Series, 321, 267281.
Loss, S.R., Will, T. & Marra, P.P. (2014) Refining estimates of bird collision and electrocution mortality at power lines in the United States. PLOS ONE, 9, e101565.
Loss, S.R., Will, T. & Marra, P.P. (2015) Direct mortality of birds from anthropogenic causes. Annual Review of Ecology, Evolution, and Systematics, 46, 99120.
Luzenski, J., Rocca, C.E., Harness, R.E., Cummings, J.L., Austin, D.D., Landon, M.A. & Dwyer, J.F. (2016) Collision avoidance by migrating raptors encountering a new electric power transmission line. The Condor, 118, 402410.
Mahood, S.P., Silva, J.P., Dolman, P.M. & Burnside, R.J. (2016) Proposed power transmission lines in Cambodia constitute a significant new threat to the largest population of the Critically Endangered Bengal florican Houbaropsis bengalensis. Oryx, 52, 147155.
Marcelino, J., Moreira, F., Mañosa, S., Cuscó, F., Morales, M.B., García de la Morena, E.L. et al. (2018) Tracking data of the Little Bustard Tetrax tetrax in Iberia shows high anthropogenic mortality. Bird Conservation International, 28, 509520.
Marques, A.T., Rocha, P. & Silva, J.P. (2007) Monitorização dos Efeitos da Linha de Muito Alta Tensão Ferreira do Alentejo/Ourique sobre Espécies Prioritárias, Mortalidade e Taxas de Voo. Instituto para a Conservação da Natureza, Lisbon, Portugal.
Martin, G.R. & Shaw, J.M. (2010) Bird collisions with power lines: failing to see the way ahead? Biological Conservation, 143, 26952702.
Moreira, F., Silva, J.P., Estanque, B., Palmeirim, J.M., Lecoq, M., Pinto, M. et al. (2012) Mosaic-level inference of the impact of land cover changes in agricultural landscapes on biodiversity: a case-study with a threatened grassland bird. PLOS ONE, 7, e38876.
Murphy, R.K., Dwyer, J.F., Mojica, E.K., McPherron, M.M. & Harness, R.E. (2016) Reactions of sandhill cranes approaching a marked transmission power line. Journal of Fish and Wildlife Management, 7, 480489.
Neves, J., Infante, S., Ministro, J. & Brandão, R. (2005) Estudo sobre o Impacto das Linhas Eléctricas de Muito Alta Tensão na Avifauna em Portugal. [in Portuguese] Quercus Associação Nacional de Conservação da Natureza e SPEA Sociedade Portuguesa para o Estudo das Aves, Castelo Branco, Portugal.
Palacín, C., Alonso, J.C., Martín, C.A. & Alonso, J.A. (2017) Changes in bird-migration patterns associated with human-induced mortality. Conservation Biology, 31, 106115.
Pinto, M., Rocha, P. & Moreira, F. (2005) Long-term trends in great bustard (Otis tarda) populations in Portugal suggest concentration in single high quality area. Biological Conservation, 124, 415423.
Ponce, C., Alonso, J.C., Argandoña, G., García Fernández, A. & Carrasco, M. (2010) Carcass removal by scavengers and search accuracy affect bird mortality estimates at power lines. Animal Conservation, 13, 603612.
R Core Team (2016) R: a Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. [accessed 19 July 2019].
Raab, R., Spakovszky, P., Julius, E., Schütz, C. & Schulze, C.H. (2011) Effects of power lines on flight behaviour of the West-Pannonian great bustard Otis tarda population. Bird Conservation International, 21, 142155.
Raab, R., Schütz, C., Spakovszky, P., Julius, E. & Schulze, C.H. (2012) Underground cabling and marking of power lines: conservation measures rapidly reduced mortality of West-Pannonian great bustards Otis tarda. Bird Conservation International, 22, 299306.
Rayner, J.M.V. (1988) Form and function in avian flight. In Current Ornithology (ed. Johnston, R.F.), pp. 166. Springer, Boston, USA.
Rhodes, J.R., McAlpine, C.A., Zuur, A.F., Smith, G.M. & Ieno, E.N. (2009) GLMM applied on the spatial distribution of koalas in a fragmented landscape. In Mixed Effects Models and Extensions in Ecology with R, pp. 469492. Springer, New York, USA.
Rivas-Martínex, S., Díaz, T.E., Fernández-González, F., Izco, J., Loidi, J., Lousã, M. & Penas, A. (2002) Vascular plant communities of Spain and Portugal. Itinera Geobotanica, 15, 5432.
Rocha, P. (2006) Dinâmica Populacional e Distribuiçao da Abetarda no Baixo Alentejo–Relaçao com o Uso da Terra. Universidade Técnica de Lisboa, Instituto Superior de Agronomia, Lisbon, Portugal.
Shaw, J.M., Jenkins, A.R., Smallie, J.J. & Ryan, P.G. (2010) Modelling power-line collision risk for the Blue Crane Anthropoides paradiseus in South Africa. Ibis, 152, 590599.
Shaw, J.M., Reid, T.A., Schutgens, M., Jenkins, A.R. & Ryan, P.G. (2017) High power line collision mortality of threatened bustards at a regional scale in the Karoo, South Africa. Ibis, 160, 431446.
Silva, J.P. & Pinto, M. (2006) Relatório Final da Acção 2 do Projecto Life Natureza (LIFE02NAT/P/8476), Tetrax: Conservação do Sisão no Alentejo – Inventário dos Núcleos de Sisão no Alentejo. Instituto da Conservação da Natureza, Lisbon, Portugal.
Silva, J., Faria, N. & Catry, T. (2007) Summer habitat selection and abundance of the threatened little bustard in Iberian agricultural landscapes. Biological Conservation, 139, 186194.
Silva, J.P., Palmeirim, J.M., Alcazar, R., Correia, R., Delgado, A. & Moreira, F. (2014) A spatially explicit approach to assess the collision risk between birds and overhead power lines: a case study with the little bustard. Biological Conservation, 170, 256263.
Silva, J.P., Correia, R., Alonso, H., Martins, R.C., D'Amico, M., Delgado, A. et al. (2018) EU protected area network did not prevent a country wide population decline in a threatened grassland bird. PeerJ, 6, e4284.
Smith, A.N., Duffy, C.A.J. & Leathwick, J.R. (2013) Predicting the Distribution and Relative Abundance of Fishes on Shallow Subtidal Reefs Around New Zealand. Science for Conservation, 323, Publishing Team, New Zealand Department of Conservation, Wellington, New Zealand.
Suárez-Seoane, S., Osborne, P.E. & Alonso, J.C. (2002) Large-scale habitat selection by agricultural steppe birds in Spain: identifying species-habitat responses using generalized additive models. Journal of Applied Ecology, 39, 755771.
Zuur, A.F., Ieno, E.N., Walker, N., Saveliev, A.A. & Smith, G.M. (2009) Mixed Effects Models and Extensions in Ecology with R. Springer New York, New York, USA.


Type Description Title
Supplementary materials

Marques et al. supplementary material
Table S1 and Figures S1-S6

 PDF (432 KB)
432 KB

Power line routing and configuration as major drivers of collision risk in two bustard species

  • Ana Teresa Marques (a1), Ricardo C. Martins (a2), João Paulo Silva (a2), Jorge M. Palmeirim (a1) and Francisco Moreira (a2)...


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed