Biodiversity and Conservation

, Volume 28, Issue 3, pp 603–619 | Cite as

Constraints on raptor distribution at the southwestern boundary of the Palaearctic: implications for conservation

  • José Luis TelleríaEmail author
  • Guillermo Fandos
  • Elena Tena
  • Roberto Carbonell
  • Alejandro Onrubia
  • Abdeljebbar Qninba
  • Álvaro Ramírez
Original Paper


Populations at the far edges of their ranges tend to be scarce, and they are frequently of conservation concern. This paper examines the distribution of three raptors (Circaetus gallicus, Hieraaetus pennatus and Milvus migrans) at the southwestern boundary of their breeding range. We modelled species distribution to obtain habitat suitability indexes that were validated with extensive fieldwork in Morocco and Spain. Our results support a strong effect of habitat suitability and a bottleneck effect of the Strait of Gibraltar on raptor distribution. However, after controlling for these effects, the three species were scarcer in Morocco than in Spain. We did not find differences between the two countries in the number of power lines that are dangerous to raptors or in general impacts of agricultural intensification on bird populations (we assessed more farmland birds in Morocco). However, many more people (i.e., shepherds) were detected in Morocco, whose negative effect on raptors could explain the depletion of their populations. These transboundary differences are used to discuss the fate of these peripheral populations in a context of climate change and rural abandonment. They also highlight the need for strengthening raptor conservation around the Strait of Gibraltar, where a permanent flow of raptors converges throughout the year.


Bottleneck effect Habitat suitability Human interference Peripheral population Species range Transboundary difference 



We thank M. J. de Lope, R. Pérez-Gomariz, A. Perry, S. Young and T. Santos for support with several aspects of this study. Three anonymous reviewers considerably improved an early version of this manuscript. This paper is a contribution to the projects CGL2011-22953/BOS and CGL2017-85637-P of the Spanish Ministry of Economy and Competitiveness and the UCM-Santander project PR26/16-20244.


  1. Anadón JD, Sánchez-Zapata JA, Carrete M, Donázar JA, Hiraldo F (2010) Large-scale human effects on an arid African raptor community. Anim Conserv 13:495–504. CrossRefGoogle Scholar
  2. Arrondo E, Moleón M, Cortés-Avizanda A, Jiménez J, Beja P, Sánchez-Zapata JA, Donázar JA (2018) Invisible barriers: differential sanitary regulations constrain vulture movements across country borders. Biol Conserv 219:46–52. CrossRefGoogle Scholar
  3. Barbet-Massin M, Jiguet F, Albert CH, Thuiller W (2012) Selecting pseudo-absences for species distribution models: how, where and how many? Methods Ecol Evol 3:327–338. CrossRefGoogle Scholar
  4. Bartoń K (2015) MuMIn: multi-model inference. R package version 1.13.4.
  5. Battisti C (2014) Peninsular patterns in biological diversity: historical arrangement, methodological approaches and causal processes. J Nat Hist 48:2701–2732. CrossRefGoogle Scholar
  6. Bicheron P, Defourny P, Brockmann C, Schouten L, Vancutsem C, Huc M, Bontemps S, Leroy M, Achard F, Herold M, Ranera F, Arino O (2008) GlobCover: products description and validation report. Medias France, ToulouseGoogle Scholar
  7. Bildstein KL, Zalles JI, Ottinger J, McCarty K (2000) Conservation biology of the world’s migratory raptors: status and strategies. In: Chancellor RD, Meyburg BU (eds) Raptors at risk: proceedings of the fifth World Conference on Birds of Prey and Owls. Springer, Berlin, pp 573–590Google Scholar
  8. BirdLife International (2017) European birds of conservation concern: populations, trends and national responsibilities. BirdLife International, CambridgeGoogle Scholar
  9. Boakes EH, Isaac NJ, Fuller RA, Mace GM, McGowan PJ (2017) Examining the relationship between local extinction risk and position in range. Conserv Biol 32:229–239. CrossRefGoogle Scholar
  10. Burnham KP, Anderson DR (2002) Model selection and multimodel inference: a practical information-theoretic approach, 2nd edn. Springer-Verlag, New YorkGoogle Scholar
  11. Carlon J (1996) Response of Booted Eagles to human disturbance. Br Birds 89:267–274Google Scholar
  12. Cherkaoui I, Bouajaja A, Hanane S (2013) Evidence of increasing Lesser Kestrel Falco naumanni populations in Morocco (North Africa): a confirmation of “Least Concern” conservation status. Bird Study 60:423–427. CrossRefGoogle Scholar
  13. Cox CB (2001) The biogeographic regions reconsidered. J Biogeogr 28:511–523. CrossRefGoogle Scholar
  14. Dallimer M, Strange N (2015) Why socio-political borders and boundaries matter in conservation. Trends Ecol Evol 30:132–139. CrossRefGoogle Scholar
  15. Di Cola V, Broennimann O, Petitpierre B, Breiner FT, D’Amen M, Randin C, Engler R, Pottier J, Pio D, Dubuis A, Pellissier L, Mateo RG, Hordijk W, Salamin N, Guisan A (2017) ecospat: an R package to support spatial analyses and modeling of species niches and distributions. Ecography 40:774–787. CrossRefGoogle Scholar
  16. Díaz J, Cebollada F (2011) Seguimiento y conservación de la aguililla calzada (Aquila pennata) en la sierra de Guadarrama (España Central). In: Zuberogoitia I, Martínez JE (eds) Ecología y Conservación de las Rapaces Forestales Europeas. Diputación Foral de Bizkaia, Bilbao, pp 93–98Google Scholar
  17. Donald PF, Sanderson FJ, Burfield IJ, Van Bommel FP (2006) Further evidence of continent-wide impacts of agricultural intensification on European farmland birds, 1990–2000. Agric Ecosyst Environ 116:189–196. CrossRefGoogle Scholar
  18. Donázar JA, Cortés-Avizanda A, Fargallo JA, Margalida A, Moleón M, Morales-Reyes Z, Moreno-Opo R, Pérez-García JM, Sánchez-Zapata JA, Zuberogoitia I, Serrano D (2016) Roles of raptors in a changing world: from flagships to providers of key ecosystem services. Ardeola 63:181–234. CrossRefGoogle Scholar
  19. Elith J, Leathwick JR (2009) Species distribution models: ecological explanation and prediction across space and time. Annu Rev Ecol Evol S 40:677–697. CrossRefGoogle Scholar
  20. Emmerson M, Morales MB, Oñate JJ, Batáry P, Berendse F, Liira J, Aavik T, Guerrero I, Bommarco R, Eggers S, Pärt T, Tscharntke T, Weisser W, Clement L, Bengtsson J (2016) How agricultural intensification affects biodiversity and ecosystem services. Adv Ecol Res 55:43–97. CrossRefGoogle Scholar
  21. Fandos G, Tellería JL (2017) Range compression of migratory passerines in wintering grounds of the Western Mediterranean: conservation prospects. Bird Conserv Int 5:20. Google Scholar
  22. Fick SE, Hijmans RJ (2017) WorldClim 2: new 1-km spatial resolution climate surfaces for global land areas. Int J Climatol 37:4302–4315. CrossRefGoogle Scholar
  23. Fuller M, Mosher J (1981) Methods of detecting and counting raptors a review. Stud Avian Biol Ser 6:235–246Google Scholar
  24. Garcia EFJ, Bensusan KJ (2006) Northbound migrant raptors in June and July at the Strait of Gibraltar. Br Birds 99:569–575Google Scholar
  25. García-Dios IS (2014) Aguililla calzada—Hieraaetus pennatus. In: Salvador A, Morales MB (eds) Enciclopedia Virtual de los Vertebrados. Españoles. Museo Nacional de Ciencias Naturales, Madrid. Accessed 1 April 2018
  26. García-Mudarra JL, Ibañez C, Juste J (2009) The Straits of Gibraltar: barrier or bridge to Ibero-Moroccan bat diversity? Biol J Linn Soci 96:434–450. CrossRefGoogle Scholar
  27. Garrido JR, Camiña A, Guinda M, Egea M, Mouati N, Godino A, Paz de la Rocha JL (2005) Absence of the Eurasian Griffon (Gyps fulvus) in northern Morocco. J Raptor Res 39:70–74Google Scholar
  28. Garrido JR, Guinda M, Godino A, Cherkaoui SI, Bouajaja A, Khamlichi EL (2014) Caracterización del uso del veneno en la Península de Yebala y Marruecos y su afección a la fauna amenazada andaluza. Consejería de Medio Ambiente y Ordenación del Territorio, Junta de Andalucía, SevillaGoogle Scholar
  29. Giorgi F (2006) Climate change hot-spots. Geophys Res Lett 33:L08707. CrossRefGoogle Scholar
  30. Giorgi F, Lionello P (2008) Climate change projections for the Mediterranean region. Glob Planet Change 63:90–104. CrossRefGoogle Scholar
  31. Godino A, Garrido JR, El Khamlichi R, Burón D, Machado C, Amezian M, Irizi A, Numa C, Barrios V (2016) Identification de la mortalité des rapaces par électrocution dans le sud-ouest du Maroc. UICN, MálagaGoogle Scholar
  32. Hampe A, Petit RJ (2005) Conserving biodiversity under climate change: the rear edge matters. Ecol Lett 8:461–467. CrossRefGoogle Scholar
  33. Hijmans RJ (2015) raster: geographic data analysis and modeling. R package version 2.5.2.
  34. Hijmans RJ, Phillips S, Leathwick J, Elith J (2015). dismo: Species distribution modeling. R package version 1.0-12. The R Foundation for Statistical Computing, Vienna.
  35. Lavergne S, Hampe A, Arroyo J (2013) In and out of Africa: how did the Strait of Gibraltar affect plant species migration and local diversification? J Biog 40:24–36. CrossRefGoogle Scholar
  36. Lehman RN, Kennedy PL, Savidge JA (2007) The state of the art in raptor electrocution research: a global review. Biol Conserv 135:459–474. CrossRefGoogle Scholar
  37. López-Iborra GM, Limiñana R, Pavón D, Martínez-Pérez JE (2011) Modelling the distribution of short-toed eagle (Circaetus gallicus) in semi-arid Mediterranean landscapes: identifying important explanatory variables and their implications for its conservation. Eur J Wildl Res 57:83–93. CrossRefGoogle Scholar
  38. López-López P, de La Puente J, Mellone U, Bermejo A, Urios V (2016) Spatial ecology and habitat use of adult Booted Eagles (Aquila pennata) during the breeding season: implications for conservation. J Ornithol 157:981–993. CrossRefGoogle Scholar
  39. Martí R, del Moral JC (2003) Atlas de las Aves reproductoras de España. SEO/BirdLife y Dirección General de Conservación de la Naturaleza, MadridGoogle Scholar
  40. Martínez JE, Pagán I, Palazón JA, Calvo JF (2006) Habitat use of booted eagles (Hieraaetus pennatus) in a special protection area: implications for conservation. Biodivers Conserv 16:3481–3488. CrossRefGoogle Scholar
  41. Martínez JE, Zuberogoitia I, Jiménez-Franco MV, Mañosa S, Calvo JF (2016) Spatio-temporal variations in mortality causes of two migratory forest raptors in Spain. Eur J Wildlife Res 62:109–118. CrossRefGoogle Scholar
  42. Martínez-Abraín A, Crespo J, Jiménez J, Gómez JA, Oro D (2009) Is the historical war against wildlife over in southern Europe? Anim Conserv 12:204–208. CrossRefGoogle Scholar
  43. Mellone U, Yáñez B, Limiñana R, Muñoz AR, Pavón D, González JM, Urios V, Ferrer M (2011) Summer staging areas of non-breeding Short-toed Snake Eagles Circaetus gallicus. Bird Study 58:516–521. CrossRefGoogle Scholar
  44. Meyburg BU, Meyburg C, Pacteau C (1996) Migration autumnale d’un circaete Jean-le Blanc Circaetus gallicus suivi par satellite. Alauda 64:339–344Google Scholar
  45. Miller RA, Onrubia A, Martín B, Kaltenecker GS, Carlisle JD, Bechard MJ, Ferrer M (2016) Local and regional weather patterns influencing post-breeding migration counts of soaring birds at the Strait of Gibraltar, Spain. Ibis 158:106–115. CrossRefGoogle Scholar
  46. Newton I (1979) Population Ecology of Raptors. T&AD Poyser, BerkhamstedGoogle Scholar
  47. Ontiveros D (2016) Culebrera Europea—Circaetus gallicus. In: Salvador A, Morales MB (eds) Enciclopedia Virtual de los Vertebrados Españoles. Museo Nacional de Ciencias Naturales, Madrid. Accessed 1 April 2018
  48. Oro D, Genovart M, Tavecchia G, Fowler MS, Martínez-Abraín A (2013) Ecological and evolutionary implications of food subsidies from humans. Ecol Lett 16:1501–1514. CrossRefGoogle Scholar
  49. Palomino D (2016) Milano negro—Milvus migrans. In: Salvador A, Morales MB (eds) Enciclopedia Virtual de los Vertebrados Españoles. Museo Nacional de Ciencias Naturales, Madrid. Accessed 1 April 2018
  50. Pautasso M (2007) Scale dependence of the correlation between human population presence and vertebrate and plant species richness. Ecol Lett 10:16–24. CrossRefGoogle Scholar
  51. Penteriani V, Otalora F, Sergio F, Ferrer M (2005) Environmental stochasticity in dispersal areas can explain the ‘mysterious’ disappearance of breeding populations. Philos Trans R Soc B 272:1265–1269. Google Scholar
  52. Peterson AT, Soberón J, Pearson RG, Anderson RP, Martínez-Meyer E, Nakamura M, Araújo MB (2011) Ecological niches and geographic distributions. Princeton University Press, PrincetonCrossRefGoogle Scholar
  53. Phillips SJ, Dudik M, Elith J, Graham C, Lehmann A, Leathwick J, Ferier S (2009) Sample selection bias and presence-only models of species distributions. Ecol Appl 19:181–197. CrossRefGoogle Scholar
  54. Phillips SJ, Anderson RP, DudÍk M, Schapire RE, Blair ME (2017) Opening the black box: an open-source release of Maxent. Ecography 40:887–893. CrossRefGoogle Scholar
  55. Porter RF, Beaman MAS (1985) A resume of raptor migration in Europe and the Middle East. In: Newton I, Chancellor RD (eds) Conservation studies on raptors. ICBP Technical Publication, Norwich, pp 237–242Google Scholar
  56. R Core Team (2017) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.
  57. Sanderson EW, Jaiteh M, Levy MA, Redford KH, Wannebo AV, Woolmer G (2002) The human footprints and the last of the wild. Bioscience 52:891–904.;2 CrossRefGoogle Scholar
  58. Sergio F, Tanferna A, De Stephanis R, López Jiménez L, Blas J, Hiraldo F (2017) Migration by breeders and floaters of a long-lived raptor: implications for recruitment and territory quality. Anim Behav 131:59–72. CrossRefGoogle Scholar
  59. Sexton JP, McIntyre PJ, Angert AM, Rice JK (2009) Evolution and Ecology of SpeciesRange Limits. Annu Rev Ecol Evol S. 40:415–436. CrossRefGoogle Scholar
  60. Soberón J, Peterson AT (2005) Interpretation of models of fundamental ecological niches and species’ distributional areas. Biodiv Inform 2:1–10. CrossRefGoogle Scholar
  61. Sullivan BL, Aycrigg JL, Barry JH, Bonney RE, Bruns N, Cooper CB, Fink D (2014) The eBird enterprise: an integrated approach to development and application of citizen science. Biol Conserv 169:31–40. CrossRefGoogle Scholar
  62. Tanferna A, López-Jiménez L, Blas J, Hiraldo F, Sergio F (2013) Habitat selection by Black kite breeders and floaters: implications for conservation management of raptor floaters. Biol Conserv 160:1–9. CrossRefGoogle Scholar
  63. Tellería JL, Fandos G, López JF, Onrubia A, Refoyo P (2014) Winter Distribution of passerine richness in the maghreb (North Africa): a conservation assessment. Ardeola 61:335–350. CrossRefGoogle Scholar
  64. Thévenot M, Bergier P, Beaubrun P (1985) Present distribution and status of raptors in Morocco. In: Newton I, Chancellor RD (eds) Conservation studies on raptors, vol 5. ICBP Technical Publications. International Council for Bird Preservation, Cambridge, pp 83–101Google Scholar
  65. Thévenot M, Vernon R, Bergier P (2003) The birds of Morocco. BOU Checklist no. 20. BOU, TringGoogle Scholar
  66. Tintó A, Real J, Mañosa S (2010) Predicting and correcting electrocution of birds in Mediterranean Areas. J Wildl Manage 74:1852–1862. CrossRefGoogle Scholar
  67. Weber MM, Stevens RD, Diniz-Filho JAF, Grelle CEV (2016) Is there a correlation between abundance and environmental suitability derived from ecological niche modelling? A meta-analysis. Ecography 40:817–828. CrossRefGoogle Scholar
  68. Williams VL, Cunningham AB, Kemp AC, Bruyns RK (2014) Risks to birds traded for African traditional medicine: a quantitative assessment. PLoS ONE 9:e105397. CrossRefGoogle Scholar
  69. World Bank (2008) World Bank Open Data. Accessed 1 March 2018
  70. Zuur AF, Ieno EN, Elphick CS (2010) A protocol for data exploration to avoid common statistical problems. Methods Ecol Evol 1:3–14. CrossRefGoogle Scholar

Copyright information

© Springer Nature B.V. 2018

Authors and Affiliations

  1. 1.Department of Biodiversity, Ecology and EvolutionUniversidad ComplutenseMadridSpain
  2. 2.Fundación MigresCádizSpain
  3. 3.Laboratoire de Géo-Biodiversité et Patrimoine Naturel (GEOBIO), Institut ScientifiqueMohammed V UniversityAgdalMorocco

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