Journal of Ornithology

, 151:1 | Cite as

Wide-range dispersal in juvenile Eagle Owls (Bubo bubo) across the European Alps calls for transnational conservation programmes

  • Adrian Aebischer
  • Peter Nyffeler
  • Raphaël Arlettaz
Original Article


Although juvenile dispersal is an important life history component, it remains one of the less understood ecological processes regulating the dynamics of animal populations. Lack of information about patterns of dispersal hampers the estimation of the actual status and demographic trajectory of populations, and can preclude the development of sound conservation strategies. The Eagle Owl Bubo bubo is an endangered bird species in the European Alps. Many breeding sites have been abandoned in the twentieth century, although some recovery has been reported lately. Moreover, the occupancy of traditional breeding sites across years in well-monitored Alpine populations varies a lot, this despite a relatively high breeding success at the population level. This raises concern about the long-term persistence of Alpine populations. Using conventional and satellite radiotracking, we investigated the spatio-temporal dispersal of 41 juvenile Eagle Owls originating from a population in the southwestern Swiss Alps. Our main goal was to determine dispersal distances, places and times of post-dispersal settlement. Juveniles left their parents between mid-August and mid-November. They covered, on average, 12.7 km per night (linear distance between two consecutive day roosts), often crossing high mountain ranges (up to 3,000 m altitude). The mean total distance covered by an individual during dispersal was 102 km (sum of night movements), with a maximum of 230 km. Settlement places were, on average, 46 km distant from the birth place. Our study establishes long-distance dispersal in juvenile Eagle Owls, even in a complex topography, suggesting the existence of a wide-scale metapopulation system across the northwestern Alps. This metapopulation dimension should be accounted for in conservation plans.


Alps Bubo bubo Floater Juvenile dispersal Satellite telemetry 



The present study was funded by grants from the MAVA Foundation for the Protection of Nature, by the Loterie Romande, by the Zürcher Tierschutz and by the Swiss Ornithological Institute. We also acknowledge the financial support of the Rita Roux foundation, the Museum of Natural History in Fribourg and the Cercle Ornithologique de Fribourg. Many thanks to S. Mettaz, P. Grand, N. Jordan, J.-L. Abbet, F. Desmet, S. Koch, R. Lardelli, R. Bionda, G. Rochat, C. Grand and V. Dupuis for assistance in field work and for reporting their observations. We are grateful to B. Muffat-Joly and M. Arvin-Berod from the Office National de la Chasse et de la Faune Sauvage for the many field controls they made in Haute-Savoie. Thanks also to the gamekeepers from the cantons of Valais, Vaud and Bern for various forms of collaboration and to the Swiss Ornithological Institute that made available the ring recovery data from their archive. Finally, we thank V. Penteriani and L. Dalbeck for their valuable comments on the manuscript. Licences statement: this study has been carried out in full compliance with the Swiss legislation under licence from the Swiss Federal Office for the Environment and the cantonal Game and Fishery Services of Valais and Vaud, and following the guidelines for the use of free-ranging, wild animals in research.


  1. Aebischer A, Nyffeler P, Koch S, Arlettaz R (2005) Jugenddispersion und Mortalität Schweizer Uhus Bubo bubo – Ein aktueller Zwischenbericht. Ornithol Anz 44:197–200Google Scholar
  2. Arlettaz R (1988) Statut du hibou grand-duc, Bubo bubo, en Valais Central. Bull Murith 106:3–23Google Scholar
  3. Batschelet E (1981) Circular statistics in biology. Academic, LondonGoogle Scholar
  4. Bowler DE, Benton TG (2005) Causes and consequences of animal dispersal strategies: relating individual behaviour to spatial dynamics. Biol Rev Camb Philos Soc 80:205–225. doi: 10.1017/S1464793104006645 CrossRefPubMedGoogle Scholar
  5. Brawn JD, Robinson SK (1996) Source-sink population dynamics may complicate the interpretation of long-term census data. Ecology 77:3–12. doi: 10.2307/2265649 CrossRefGoogle Scholar
  6. Breuer W (2007) Stromopfer und Vogelschutz an Energiefreileitungen. Bundesnaturschutzgesetz in der Praxis. Natursch Landsch 39:69–95Google Scholar
  7. Breuer W, Brücher W, Dalbeck L (2009) Straßentod von Vögeln - Zur Frage der Erheblichkeit am Beispiel des Uhus. Natursch Landsch 41:41–46Google Scholar
  8. Burnham KP (1993) A theory for combined analysis of ring recovery and recapture data. In: Lebreton JD, North PM (eds) Marked individuals in the study of bird population. Birkhäuser, Basel, pp 199–213Google Scholar
  9. Clobert J, Danchin E, Dhondt A, Nichols JD (2001) Dispersal. Oxford University Press, OxfordGoogle Scholar
  10. Cochet G (2006) Le grand-duc d’Europe. Delachaux et Niestlé, ParisGoogle Scholar
  11. Defontaines P (2002) Suivi sur 20 ans d’une population de Grands-ducs d’Europe Bubo bubo en Languedoc. Alauda 70:15–22Google Scholar
  12. Delgado MM, Penteriani V (2005) Eagle owl Bubo bubo dispersal patterns and the importance of floaters for the stability of breeding populations. Ornithol Anz 44:153–158Google Scholar
  13. Delgado MM, Penteriani V (2008) Behavioral states help translate dispersal movements into spatial distribution patterns of floaters. Am Nat 172:475–485. doi: 10.1086/590964 CrossRefGoogle Scholar
  14. Fiedler W (2005) Ist Uhuberingung noch zeitgemäß? Anforderungen an Uhu-Beringungsprogramme aus Sicht der Vogelwarte. Ornithol Anz 44:171–176Google Scholar
  15. Glutz von Blotzheim UN, Bauer K (1980) Handbuch der Vögel Mitteleuropas, vol. 9. Akademische, WiesbadenGoogle Scholar
  16. Görner M (1985) Aktuelle Probleme des Uhuschutzes (Bubo bubo) in Thüringen. Veröf Mus Gera. Naturwiss R 11:70–73Google Scholar
  17. Haftorn S (1971) Norges Fugler. Universitetsforlaget, OsloGoogle Scholar
  18. Hays GC, Akesson S, Godley BJ, Luschi P, Santidrian P (2001) The implications of location accuracy for the interpretation of satellite-tracking data. Anim Behav 61:1035–1040. doi: 10.1006/anbe.2001.1685 CrossRefGoogle Scholar
  19. Johst K, Brandl R, Eber S (2002) Metapopulation persistence in dynamic landscapes: the role of dispersal distance. Oikos 98:263–270. doi: 10.1034/j.1600-0706.2002.980208.x CrossRefGoogle Scholar
  20. Marchesi L, Sergio F, Pedrini P (2002) Costs and benefits of breeding in human-altered landscapes for the eagle owl Bubo bubo. Ibis 144:164–177. doi: 10.1046/j.1474-919X.2002.t01-2-00094_2.x CrossRefGoogle Scholar
  21. Mebs T, Scherzinger W (2000) Die Eulen Europas. Franckh-Kosmos, StuttgartGoogle Scholar
  22. Mosimann-Kampe P, Haller H, Arlettaz R (1998) Verbreitung und Bestand des Uhus Bubo bubo in der Schweiz. Ornithol Beob 95:143–151Google Scholar
  23. Nathan R (2001) The challenges of studying dispersal. Trends Ecol Evol 16:481–483. doi: 10.1016/S0169-5347(01)02272-8 CrossRefGoogle Scholar
  24. Olsson V (1979) Studies on a population of eagle owls Bubo bubo (L.) in southeast Sweden. Viltrevy (Stockh) 11:1–93Google Scholar
  25. Olsson V (1997) Breeding success, dispersal, and long-term changes in a population of eagle owls Bubo bubo in southeastern Sweden 1952–1996. Ornis Svec 7:49–60Google Scholar
  26. Penteriani V, Delgado MM, Maggio C, Aradis A, Sergio F (2005) Development of chicks and predispersal behaviour of young eagle owls Bubo bubo. Ibis 147:155–168. doi: 10.1111/j.1474-919x.2004.00381.x CrossRefGoogle Scholar
  27. Penteriani V, Otalora F, Ferrer M (2006) Floater dynamics can explain positive patterns of density-dependent fecundity in animal populations. Am Nat 168:697–703. doi: 10.1086/507995 CrossRefPubMedGoogle Scholar
  28. Radler K (1991) Populationsbiologische Untersuchungen zum Artenschutz beim Uhu (Bubo bubo). Gott Forstgen Ber 11:1–112Google Scholar
  29. Rockenbauch D (1978) Untergang und Wiederkehr des Uhus Bubo bubo in Baden-Württemberg. Anz Orn Ges Bayern 17:293–328Google Scholar
  30. Rohner C (1997) Non-territorial floaters in great horned owls (Bubo virginianus). In: Duncan JR, Johnson DH, Nicholls TH (eds) Biology and conservation of owls of the northern hemisphere. US Department of Agriculture, Forest Service, St. Paul MI, pp 347–362Google Scholar
  31. Rubolini D, Bassi E, Bogliani G, Galeotti P, Garavaglia R (2001) Eagle owl Bubo bubo and power lines interactions in the Italian Alps. Bird Conserv Int 11:319–324. doi: 10.1017/S0959270901000363 CrossRefGoogle Scholar
  32. Saurola P (2002) Natal dispersal distances of Finnish owls: results from ringing. In: Newton I, Kavanagh R, Olsen J, Taylor I (eds) Ecology and conservation of owls. CSIRO, Collingwood, pp 42–55Google Scholar
  33. Saurola P Francis CM (2004) Estimating population dynamics and dispersal distances of owls from nationally coordinated ringing data in Finland. Anim Biodivers Conserv 27:403–415Google Scholar
  34. Scherzinger W (1974) Die Jugendentwicklung des Uhus (Bubo bubo) mit Vergleichen zu der von Schneeule (Nyctea scandiaca) und Sumpfohreule (Asio flammeus). Bonn Zool Beitr 25:123–147Google Scholar
  35. Scherzinger W (1987) Der Uhu Bubo bubo im Inneren Bayerischen Wald. Anz Orn Ges Bayern 26:1–51Google Scholar
  36. Schmid H, Luder R, Naef-Daenzer B, Graf R, Zbinden N (1998) Schweizer Brutvogelatlas. Schweizerische Vogelwarte Sempach, SempachGoogle Scholar
  37. Sergio F, Marchesi L, Pedrini P, Ferrer M, Penteriani V (2004) Electrocution alters the distribution and density of a top predator. J Appl Ecol 41:836–845. doi: 10.1111/j.0021-8901.2004.00946.x CrossRefGoogle Scholar
  38. Valkama J, Saurola P (2005) Mortality factors and population trends of eagle owls Bubo bubo in Finland. Ornithol Anz 44:81–90Google Scholar
  39. Vincent C, McConnell BJ, Ridoux V, Fedak MA (2002) Assessment of Argos location accuracy from satellite tags deployed on captive gray seals. Mar Mamm Sci 18:156–166. doi: 10.1111/j.1748-7692.2002.tb01025.x CrossRefGoogle Scholar

Copyright information

© Dt. Ornithologen-Gesellschaft e.V. 2009

Authors and Affiliations

  • Adrian Aebischer
    • 1
  • Peter Nyffeler
    • 1
  • Raphaël Arlettaz
    • 1
    • 2
    • 3
  1. 1.Division of Conservation Biology, Institute of Ecology and EvolutionUniversity of BernBernSwitzerland
  2. 2.Swiss Ornithological Institute, Valais Field StationNature CentreSalgeschSwitzerland
  3. 3.The Ecology CentreUniversity of QueenslandSt LuciaAustralia

Personalised recommendations