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Identifying key habitat and seasonal patterns of a critically endangered population of killer whales

  • Ruth Esteban (a1), Philippe Verborgh (a1), Pauline Gauffier (a1), Joan Giménez (a2), Isabel Afán (a3), Ana Cañadas (a4), Pedro García (a5), Jose Luis Murcia (a5), Sara Magalhães (a6), Ezequiel Andreu (a7) and Renaud de Stephanis (a2)...


Killer whales have been described in the Gulf of Cadiz, southern Spain, in spring and in the Strait of Gibraltar in summer. A total of 11,276 cetaceans sightings coming from different sources (dedicated research surveys, whale watching companies and opportunistic observations) were used to create two presence–‘pseudo-absence’ predictive generalized additive models (GAM), where presence data were defined as sightings of killer whales and ‘pseudo-absence’ data as sightings of other cetacean species. One model was created using spring data when killer whales’ main prey, Atlantic bluefin tuna, enter the Mediterranean Sea, and the other model used summer data when Atlantic bluefin tuna return to the Atlantic Ocean. Both model predictions show that killer whales are highly associated with a probable distribution of bluefin tuna during their migration throughout the study area, constraining their distribution to the Gulf of Cadiz in spring and the Strait of Gibraltar in spring and summer. Knowledge of the distribution of killer whales in the study area is essential to establish conservation measures for this population.


Corresponding author

Correspondence should be addressed to: R. Esteban, CIRCE, Conservation Information and Research on Cetaceans, C/Cabeza de Manzaneda 3, Algeciras-Pelayo, 11390 Cadiz, Spain email:


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Aloncle, H. (1964a) Premières observations sur les petits cétacés des côtes marocaines. Bulletin d l'Institut des Pêches Maritimes du Maroc 12, 2142.
Aloncle, H. (1964b) Note sur le thon rouge de la Baie Ibéro-Marocaine. Bulletin de l'Institut des Pêches Maritimes du Maroc 12, 4359.
Amante, C. and Eakins, B. (2009) ETOPO1 1 Arc-minute global relief model: procedures, data sources and analysis. NOAA Technical Memorandum NESDIS NGDC-24, 19 pp. March 2009.
Baird, R.W. and Dill, L.M. (1995) Occurrence and behaviour of transient killer whales: seasonal and pod-specific variability, foraging behaviour, and prey handling. Canadian Journal of Zoology, Fisheries and Aquatic Sciences 73, 13001311.
Baraza, J., Ercilla, G. and Nelson, C.H. (1999) Potential geologic hazards on the eastern Gulf of Cadiz slope (SW Spain). Marine Geology 155, 191215.
Baumgartner, M. and Mullin, K. (2001) Cetacean habitats in the northern Gulf of Mexico. Fisheries Bulletin 99, 219239.
Bayed, A. and Beaubrun, P. (1987) Les mammifères marins du Maroc: inventaire préliminaire. Mammalia 51, 437446.
Bowers, C.A. and Henderson, R.S. (1972) Project Deep Ops: deep object recovery with pilot and killer whales. San Diego, CA: Naval Undersea Center.
Braham, H.W. and Dahlheim, M.E. (1982) Killer whales in Alaska documented in the Platforms of Opportunity Program. Report of the International Whaling Commission. Cambridge: IWC.
Carder, K., Chen, F., Lee, Z., Hawes, S. and Cannizzaro, J. (2003) MODIS Ocean Science Team Algorithm Theoretical Basis Document, ATBD-MOD-19, Ver. 7. Available at: (accessed 17 July 2013).
Cañadas, A. and de Stephanis, R. (2006) Killer whale, or Orca Orcinus orca (Strait of Gibraltar subpopulation). In Reeves, R.R. and Notarbartolo di Sciara, G. (eds) The status and distribution of cetaceans in the Black Sea and Mediterranean Sea. Malaga: IUCN, Centre for Mediterranean Cooperation, pp. 3438.
Cañadas, A. and Hammond, P. (2006) Model-based abundance estimates for bottlenose dolphins off southern Spain: implications for conservation and management. Journal of Cetacean Research and Management 8, 1327.
Cañadas, A., Sagarminaga, R., de Stephanis, R., Urquiola, E. and Hammond, P.S. (2005) Habitat preference modelling as a conservation tool: proposals for marine protected areas for cetaceans in southern Spanish waters. Aquatic Conservation: Marine and Freshwater Ecosystems 15, 495521.
Casinos, A. and Vericad, J.R. (1976) The cetaceans of the Spanish coasts: a survey. Mammalia 40, 267290.
Cetti, F. (1777) Storia naturale di Sardegna. III. Anfibi e Pesci. Cagliari, Italy: Tip. Giuseppe Piattoli, 208 pp.
Collette, B., Amotin, A.F., Boustanu, A., Carpenter, K.E., De Oliveira Leite, N. Jr, Di Natale, A., Die, D., Fox, W., Fredou, F.L., Graves, J., Viera Hazin, F.H., Hinton, M., Juan Jorda, M., Schratwieser, J., Texeira Lessa, R.P., Pires Ferreira Travassos, P.E. and Uozumi, Y. (2012) Thunnus thynnus. In IUCN Red List of Threatened Species. Version 2012.2. Gland: IUCN.
Cort, J. (1990) Biología y pesca del atún rojo, ‘Thunnus thynnus’(L.), del mar Cantábrico. Publicaciones Especiales. Instituto Español de Ocenografia 4, 272.
D'Amico, A., Bergamasco, A., Zanasca, P., Carniel, S., Nacini, E., Portunato, N., Teloni, V., Mori, C. and Barbanti, R. (2003) Qualitative correlation of marine mammals with physical and biological parameters in the Ligurian Sea. IEEE Journal of Oceanic Engineering 28, 2943.
de la Serna, J.D., Alot, E., Majuelos, E. and Rioja, P. (2004) La migración trófica post reproductiva del atún rojo (Thunnus thynnus) a través del estrecho de Gibraltar. Collective Volume of Scientific Papers ICCAT 56, 11961209.
de Stephanis, R., Cornulier, T., Verborgh, P., Salazar Sierra, J., Pérez Gimeno, N. and Guinet, C. (2008a) Summer spatial distribution of cetaceans in the Strait of Gibraltar in relation to the oceanographic context. Marine Ecology Progress Series 353, 275288.
de Stephanis, R., García-Tiscar, S., Verborgh, P., Esteban Pavo, R., Pérez, S., Minvielle-Sebastia, L. and Guinet, C. (2008b) Diet of the social groups of long-finned pilot whales (Globicephala melas) in the Strait of Gibraltar. Marine Biology 154, 603612.
Dicenta, A. and Piccinetti, C. (1978) Desove del atun (Thunnus thynnus) en el Mediterráneo occidental y evaluacion directa del stock de reproductores, basado en la abundancia de sus larvas. Collective Volume of Scientific Papers ICCAT 7, 389395.
Dwyer, S. and Visser, I. (2011) Cookie cutter shark (Isistius sp.) bites on cetaceans, with particular reference to killer whales (orca) (Orcinus orca). Aquatic Mammals 37(2), 11138.
Elith, J. and Leathwick, J. (2007) Predicting species distributions from museum and herbarium records using multiresponse models fitted with multivariate adaptive regression splines. Diversity and Distributions 13, 265275.
Ercilla, G., Alonso, B. and Baraza, J. (1992) Sedimentary evolution of the northwestern Alboran Sea during the Quaternary. Geo-Marine Letters 12, 144149.
Esteban, R. (2008) Abundancia, Estructura social y Parámetros demográficos de la orca (Orcinus orca) en el Estrecho de Gibraltar. Master's thesis. Universidad de Cádiz, Spain.
Foote, A., Vilstrup, J., de Stephanis, R., Verborgh, P., Nielsen, S.C.A., Deaville, R., Kleivane, L., Martín, V., Miller, P.J.O., Øien, N., Pérez-Gil, M., Rasmussen, M., Reid, R.J., Robertson, K.M., Rogan, E., Similä, T., Tejedor, M.L., Vester, H., Víkingsson, G.A., Willerslev, E., Gilbert, M.T.P. and Piertney, S.B. (2011) Genetic differentiation among North Atlantic killer whale populations. Molecular Ecology 20, 629641.
Forney, K.A. and Wade, P. (2007) Worldwide distribution and abundance of killer whales. In Estes, J. (ed.) Whales, whaling and ocean ecosystems. Berkeley, CA: University of California Press, pp. 145162.
Fromentin, J.M. and Powers, J.E. (2005) Atlantic bluefin tuna: population dynamics, ecology, fisheries and management. Fish and Fisheries 6, 281306.
García-Tiscar, S. (2009) Interacciones entre delfines mulares y orcas con pesqeuerías en el Mar de Alborán y Estrecho de Gibraltar. PhD thesis. Universidad Autónoma de Madrid, Spain.
Guinet, C., Domenici, P., de Stephanis, R., Barrett-Lennard, L., Ford, J.K.B. and Verborgh, P. (2007) Killer whale predation on bluefin tuna: exploring the hypothesis of the endurance–exhaustion. Marine Ecology Progress Series 347, 111119.
Hamazaki, T. (2002) Spatiotemporal prediction models of cetacean habitats in the mid-western North Atlantic ocean (from Cape Hatteras, North Carolina, USA to Nova Scotia, Canada). Marine Mammal Science 18, 920939.
Hastie, T. and Tibshirani, R. (1990) Generalized additive models. Monographs on statistics and applied probability, 43. Boca Raton, FL: Chapman & Hall/CRC Press.
Hernández-Molina, F.J. (1993) Dinámica sedimentaria y evolución durante el Pleistoceno Terminal–Holoceno del margen noroccidental del Mar de Alboran. Modelo de estratigrafia secuencial de muy alta resolución en plataformas continentales. Master's thesis. Universidad de Granada, Spain.
Hernández-Molina, F., Somoza, L., Rey, J. and Pomar, L. (1994) Late Pleistocene–Holocene sediments on the Spanish continental shelves: Model for very high resolution sequence stratigraphy. Marine Geology 120, 129174.
Heyning, J.E. and Dahlheim, M.E. (1988) Orcinus orca. Mammalian Species 304, 19.
Hirzel, A.H., Helfer, V. and Metral, F. (2001) Assessing habitat-suitability models with a virtual species. Ecological Modelling 145, 111121.
Hooker, S.K., Whitehead, H. and Gowans, S. (1999) Marine Protected Area design and the spatial and temporal distribution of cetaceans in a submarine canyon. Conservation Biology 13, 592602.
Horozco, A. (1598) Historia de la ciudad de Cádiz. 2nd edition. Cadiz, Spain: El Excmo. Ayuntamiento de esta M.N.. M. L. y M. H. Ciudad.
Iñiguez, M.A. (2001) Seasonal distribution of killer whales (Orcinus orca) in Northern Patagonia, Argentina. Aquatic Mammals 27, 154161.
Leatherwood, J.S. and Dalheim, M.E. (1978) Worldwide distribution of pilot whales and killer whales. Naval Ocean Systems Center Technical Report 443, pp. 139.
Lozano, F. (1958) Los escómbridos de las aguas españolas y marroquíes y su pesca. Trabajos Instituto Español de Oceanografia 25, 254.
Lütolf, M., Kienast, F. and Guisan, A. (2006) The ghost of past species occurrence: improving species distribution models for presence-only data. Journal of Applied Ecology 43, 802815.
Mackenzie, K. (1999) Parasites as biological tags in population studies of marine organisms. Parasitology 124, S153S163.
Malod, J.A. (1982) Comparaison de l’évolution des marges continentales au Nord et au Sud de la Péninsule Ibérique. PhD thesis. Université Curie, Paris, France.
Mather, F., Mason, J. and Jones, A. (1995) Historical document: life history and fisheries of Atlantic bluefin tuna. NOAA Technical Memorandum NMFS-SEFSC-370, 163 pp.
Notarbartolo di Sciara, G. (1987) Killer whale, Orcinus orca, in the Mediterranean Sea. Marine Mammal Science 3, 356360.
Notarbartolo di Sciara, G. and Birkun, A.J. (2010) Conserving whales, dolphins and porpoises in the Mediterranean and Black Seas. ACCOBAMS status report. Monaco: ACCOBAMS, 212 pp.
Phillips, S.J. and Dudík, M. (2008) Modeling of species distributions with Maxent: new extensions and a comprehensive evaluation. Ecography 31, 161175.
Quílez-Badia, G., Cermeño, P. and Tudela, S. (2012) Movements of bluefin tuna revealed by electronic tagging in the Mediterranean sea and in Atlantic waters of Morocco in 2011. ICCAT SCRS/2012/123.
Raga, J.A., Raduán, A. and Blanco, C. (1985) Contribución al estudio de la distribución de cetàceos en el Mediterráneo y Atlantico Ibérico. Miscelánia Zoológica 9, 361366.
Ravier, C. and Fromentin, J.-M. (2001) Long-term fluctuations in the eastern Atlantic and Mediterranean bluefin tuna population. ICES Journal of Marine Science 58, 12991317.
Reid, J., Evans, P.G.H. and Northridge, S.P. (2003) Atlas of cetacean distribution in north-west European waters. Peterborough: Joint Nature Conservation Committee (JNCC), 82 pp.
Roberts, D.G. (1970) The Rif–Betic orogen in the Gulf of Cadiz. Marine Geology 9(5), M31M37.
Rodríguez-Roda, J. (1964) Talla, peso y edad de los atunes, Thunnus thynnus (L.), capturados por la almadraba de Barbate (costa sudatlántica de España) en 1963 y comparación. Investigación Pesquera 26, 348.
Schneider, D.C. (2008) Habitat selection by marine birds in relation to water depth. Ibis 139, 175178.
Sella, M. (1929) Migrazioni e habitat del tonno (Thunnus thynnus L) studiati col metodo degli ami, con osservazioni su l'accrescimento, sul regime delle tonnare ecc. Venice: Univ.-Bibliothek Frankfurt an Main.
Selzer, L.A. and Payne, P.M. (1988) The dsitribution of white-sided (Lagenorhynchus acutus) and common dolphins (Delphinus delphis) VS. environmental features of the continental shelf of the Northeastern United States. Marine Mammal Science 4, 141153.
Sigurjónsson, J. and Leatherwood, S. (1988) The Icelandic live-capture fishery for killer whales, 1976–1988. Rit Fiskideildar 11, 307316.
Srour, A. (1994) Développment de la nouvelle pêcherie artisanale au thon rouge dans la région de Ksar sghir. Note d'Information ISPM 26, 1011.
Stockwell, D. (1999) The GARP modelling system: problems and solutions to automated spatial prediction. International Journal of Geographical Information Science 13, 143158.
Torres, L.G., Rosel, P.E., D'Agrosa, C. and Read, A.J. (2003) Improving management of overlapping bottlenose dolphin ecotypes through spatial analysis and genetics. Marine Mammal Science 19, 502514.
VanDerWal, J., Shoo, L. and Januchowski, S. (2010) SDM Tools. Species Distribution Modelling Tools: tools for processing data associated with species distribution modelling exercises. R package version 1. Available at: (accessed 17 July 2013).
Verborgh, P., de Stephanis, R., Pérez, S., Yaget, Y., Barbraud, C. and Guinet, C. (2009) Survival rate, abundance, and residency of long-finned pilot whales in the Strait of Gibraltar. Marine Mammal Science 25, 523536.
Ward, E.J., Holmes, E.E. and Balcomb, K.C. (2009) Quantifying the effects of prey abundance on killer whale reproduction. Journal of Applied Ecology 46, 632640.
Wilson, S. and Block, B. (2009) Habitat use in Atlantic bluefin tuna Thunnus thynnus inferred from diving behavior. Endangered Species Research 10, 355367.
Wood, S. (2000) Modelling and smoothing parameter estimation with multiple quadratic penalties. Statistical Society: Series B 62, 413428.
Wood, S. (2001) mgcv: GAMs and generalized ridge regression for R. R News 1(2), 2025.
Wood, S. (2006) On confidence intervals for generalized additive models based on penalized regression splines. Australian and New Zealand Journal of Statistics 48, 445464.
Zaniewski, A.E., Lehmann, A. and Overton, J.M. (2002) Predicting species spatial distributions using presence-only data: a case study of native New Zealand ferns. Ecological Modelling 157, 261280.


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Identifying key habitat and seasonal patterns of a critically endangered population of killer whales

  • Ruth Esteban (a1), Philippe Verborgh (a1), Pauline Gauffier (a1), Joan Giménez (a2), Isabel Afán (a3), Ana Cañadas (a4), Pedro García (a5), Jose Luis Murcia (a5), Sara Magalhães (a6), Ezequiel Andreu (a7) and Renaud de Stephanis (a2)...


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