Behavioural ecology of urban Greylag Geese Anser anser – natural selection in the contemporary European city environment
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Abstract
The behavioural ecology of urban Greylag Geese Anser anser was reviewed in relation to selective forces or bottlenecks – such as habitat, food availability, predators, disturbance, hunting, diseases and parasites, nest sites and brood rearing areas, and competition with other species – which may act on geese in the contemporary European city environment. Special consideration was given to behavioural changes during winter and moult. Studies to date indicate that urban geese have developed survival and reproduction strategies which sometimes differ from those of geese in other habitats. For instance, they must adapt to a more built-up environment, as additional mortality may arise from collisions caused by flying within confined urban spaces. They are also exposed to urbanised native, introduced and “domestic” predators, such as dogs, to which they show size-related escape responses. Most urban geese adapt to human disturbances, adjusting the intensity of their behavioural response to the perceived danger. Like their rural counterparts, urban geese are also highly selective in their choice of food plants and feeding habitat, although supplementary feeding by people may induce a change in behaviour. There was no evidence that disease or parasite loads are higher for geese in urban than in rural areas. Urban Greylag Geese use a broader range of physical structures for nesting in urban than in rural areas, with some also adopting colonial nesting. Some families moved to new brood-rearing areas immediately post-hatching, elevating reproductive success. Competition with other species was evident at some sites, with Greylag Goose breeding success being inversely related to the local abundance of Egyptian Goose Alopochen aegyptiaca breeding pairs. Although wintry conditions with snow and ice cover may limit food availability and frozen lakes may hinder the ability of largely sedentary urban geese to escape from predators, they appear able to cope with prolonged periods of cold. Urban geese have also demonstrated resilience during their flightless wing moult period. It is unlikely that urban goose populations will grow indefinitely, as density-dependent processes will lead to a stabilisation of the numbers which occur within the boundaries of a given city, although the geese may disperse into surrounding rural areas.
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References
Adam, M., Podhrázský, M. & Musil, P. 2016. Effect of start of hunting season on behaviour of Greylag Geese Anser anser. Ardea 104: 63–68.
Adams, L.W., Van Druff, L.W. & Luniak, M. 2005. Managing urban habitats and wildlife. In C. Braun (ed.), Techniques for Wildlife Investigations and Management, pp. 714–739. Wildlife Society, Bethesda, USA.
Alcock, J. 2009. Animal Behavior: an Evolutionary Approach. Sinauer Associates, Sunderland, USA.
Allan, J.R., Kirby, J.S. & Feare, C.J. 1995. The biology of Canada geese Branta canadensis in relation to the management of feral populations. Wildlife Biology 1: 129–143.
Amat, J.A. 1986. Some aspects of the foraging ecology of a wintering Greylag Goose Anser anser population. Bird Study 33: 74–80.
Ankney, C.D. & MacInnes, C.D. 1978. Nutrient reserves and reproductive performance of female Lesser Snow Geese. The Auk 95: 459–471.
Baker, H. & Coleman, D. 2004. Status of the Canada Goose, the Greylag Goose and other naturalised geese in Greater London. London Bird Report 65: 199–205.
Balkcom, G.D. 2010. Demographic parameters of rural and urban adult resident Canada geese in Georgia. The Journal of Wildlife Management 74: 120–123.
Barber, I. & Dingemanse, N.J. 2010. Parasitism and the evolutionary ecology of animal personality. Philosophical Transactions of the Royal Society B: Biological Sciences 365: 4077–4088.
Bauer, H.G. & Woog, F. 2008. Nichtheimische vogelarten (Neozoen) in Deutschland, Teil I: Auftreten, bestände und status. Vogelwarte 46: 157–194. [In German with English summary.]
Baxter, A. & Hart, J. 2010. A review of management options for resolving conflicts with urban geese. Bird Management Unit Report. Food and Environment Research Agency, Sand Hutton, York, UK. Available at https://democracy.york.gov.uk/documents/ s42796/Yorkgoosefinal.pdf (last accessed 12 June 2025).
Beans, C. 2019. News feature: cities serve as testbeds for evolutionary change. Proceedings of the National Academy of Sciences 116: 2787–2790.
Béchet, A., Giroux, J.F. & Gauthier, G. 2004. The effects of disturbance on behaviour, habitat use and energy of spring staging snow geese. Journal of Applied Ecology 41: 689–700.
Bengtsson, K. 2007. Vitkindad gås – det rysk/ baltiska beståndets expansion. Anser 3/07: 9–34. [In Danish.]
Bergmann, H.H. 1999. Winterökologie arktischer Gänse in Deutschland. NNA-Berichte 3: 105–112. [In German.]
Black, J.M., Deerenberg, C. & Owen, M. 1991. Foraging behavior and site selection of Barnacle Geese Branta leucopsis in a traditional and newly colonised spring staging habitat. Ardea 79: 349–358.
Black, M., Prop, J. & Larsson, K. 2007. Wild Goose Dilemmas. Branta Press, Groningen, the Netherlands.
Blumstein, D.T. 2014. Attention, habituation, and antipredator behaviour: implications for urban birds. In D. Gil & H. Brumm (eds.), Avian Urban Ecology: Behavioural and Physiological Adaptations, pp. 41–53. Oxford University Press, Oxford, UK.
Borbach-Jaene, J. & Kruckenberg, H. 2002. Heute hier, morgen dort – gibt es wiederkehrende Raumnutzungsmuster bei überwinternden Blessgänsen Anser albifrons im Grünland? Die Vogelwelt 123: 1–8. [In German.]
Bos, D., Drent, R.H., Rubinigg, M. & Stahl, J. 2005. The relative importance of food biomass and quality for patch and habitat choice in Brent Geese Branta bernicla. Ardea 93: 5–16.
Bradley, C.A. & Altizer, S. 2007. Urbanization and the ecology of wildlife diseases. Trends in Ecology and Evolution 22: 95–102.
Buchanan, K.L. & Partecke, J. 2012. The endocrine system: can homeostasis be maintained in a changing world? In U. Candolin & B.B.M. Wong (eds), Behavioural Responses to a Changing World, pp. 32–45. Oxford University Press, Oxford, UK.
Caley, H.J. 2020. Seasonal and diurnal patterns of behaviour and movements of the Canada goose (Branta canadensis) in Christchurch City and Central Canterbury, New Zealand. M.Sc. thesis, University of Canterbury, Canterbury, New Zealand.
Candolin, U. & Wong, B.B.M. (eds.). 2012. Behavioural Responses to a Changing World. Oxford University Press, Oxford, UK.
Carlen, E.J., Li, R. & Winchell, K.M. 2021. Urbanization predicts flight initiation distance in feral pigeons (Columba livia) across New York City. Animal Behaviour 178: 229–245.
Carrete, M. & Tella, J.L. 2013. High individual consistency in fear of humans throughout the adult lifespan of rural and urban burrowing owls. Scientific Reports 3: 3524.
Carrete, M. & Tella, J.L. 2017. Behavioral correlations associated with fear of humans differ between rural and urban burrowing owls. Frontiers in Ecology and Evolution 5: 54.
Carrete, M., Martínez-Padilla, J., Rodríguez-Martínez, S., Rebolo-Ifrán, N., Palma, A. & Tella, J.L. 2016. Heritability of fear of humans in urban and rural populations of a bird species. Scientific Reports 6: 31060.
Chamberlain, D.E., Cannon, A.R., Toms, M.P., Leech, D.I., Hatchwell, B.J. and Gaston, K.J. 2009. Avian productivity in urban landscapes: a review and meta-analysis. Ibis 151: 1–18.
Charles-Smith, L.E., Rutledge, M.E., Meek, C.J., Baine, K., Massey, E., Ellsaesser, L.N., DePerno, C.S., Moorman, C.E. & Degernes, L.A. 2014. Hematologic parameters and hemoparasites of nonmigratory Canada geese (Branta canadensis) from Greensboro, North Carolina, USA. Journal of Avian Medicine and Surgery 28: 16–23.
Clausen, K.K., Heldbjerg, H. & Fox, A.D. 2023. Status, origin and harvest of increasing numbers of Greylag Geese Anser anser occurring in Denmark throughout the annual cycle. Wildfowl 73: 3–25.
Colsaet, A., Laurans, Y. & Levrel, H. 2018. What drives land take and urban land expansion? A systematic review. Land Use Policy 79: 339–349.
Conover, M.R. & Kania, G.S. 1991. Characteristics of feeding sites used by urban-suburban flocks of Canada geese in Connecticut. Wildlife Society Bulletin 19: 36–38.
Cooch, E.G., Jefferies, R.L., Rockwell, R.F. & Cooke, F. 1993. Environmental change and the cost of philopatry: an example in the lesser snow goose. Oecologia 93: 128–138.
Croci, S., Butet, A. & Clergeau, P. 2008. Does urbanization filter birds on the basis of their biological traits? The Condor 110: 223–240.
Davis, J.B., Guillemain, M., Kaminski, R.M., Arzel, C., Eadie, J.M. & Rees, E.C. 2014. Habitat and resource use by waterfowl in the northern hemisphere in autumn and winter. Wildfowl (Special Issue No. 4): 17–69.
Deboelpaep, E., Keleman, P.J., Vanschoenwinkel, B. & Koedam, N. 2018. Gallant geese, fearful flocks? Flock size and heterospecifics alter the escape behaviour of an invasive goose. Belgian Journal of Zoology 148: 135–147.
Delgado-V, C.A. & French, K. 2012. Parasite–bird interactions in urban areas: Current evidence and emerging questions. Landscape and Urban Planning 105: 5–14.
Donaldson, M.R., Henein, K.M. & Runtz, M.W. 2007. Assessing the effect of developed habitat on waterbird behaviour in an urban riparian system in Ottawa, Canada. Urban Ecosystems 10: 139–151.
Dorak, B.E., Ward, M.P., Eichholz, M.W., Washburn, B.E., Lyons, T.P. & Hagy, H.M. 2017. Survival and habitat selection of Canada Geese during autumn and winter in metropolitan Chicago, USA. The Condor: Ornithological Applications 119: 787–799.
Drent, R. & Prins, H.H.T. 1987. The herbivore as prisoner of its food supply. In J. van Andel, J.P. Bakker & R.W. Snaydon (eds.), Disturbance in Grasslands – Species and Population Responses, pp. 133–149. Dr. W. Junk Publishers, Dordrecht, the Netherlands.
Ebbinge, B., Canters, K. & Drent, R. 1975. Foraging routines and estimated daily food intake in Barnacle Geese wintering in the northern Netherlands. Wildfowl 26: 5–19.
Ehret, S.A., Berthoud, J.-L., Woog, F. 2020. Spring fattening in non-migratory female Greylag Geese Anser anser regardless of social status. Wildfowl 70: 257–266.
Eichholz, M.W. & Elmberg, J. 2014. Nest site selection by Holarctic waterfowl: a multi-level review. Wildfowl (Special Issue No. 4): 86–130.
Elmberg, J., Berg, C., Lerner, H., Waldenström, J. & Hessel, R. 2017. Potential disease transmission from wild geese and swans to livestock, poultry and humans: a review of the scientific literature from a One Health perspective. Infection Ecology & Epidemiology 7: 1300450.
Evans, K.L., Chamberlain, D.E., Hatchwell, B.J., Gregory, R.D. & Gaston, K.J. 2011. What makes an urban bird? Global Change Biology 17: 32–44.
Fallacara, D.M., Monahan, C.M., Morishita, T.Y. & Wack, R.F. 2001. Faecal shedding and antimicrobial susceptibility of selected bacterial pathogens and a survey of intestinal parasites in free-living waterfowl. Avian Diseases 45: 128–135.
Feare, C.J., Sanders, M.F., Blasco, R. & Bishop, J.D. 1999. Canada goose (Branta canadensis) droppings as a potential source of pathogenic bacteria. The Journal of the Royal Society for the Promotion of Health 119: 146–155.
Fernandez-Juricic, E. & Jokimäki, J. 2001. A habitat island approach to conserving birds in urban landscapes: case studies from southern and northern Europe. Biodiversity & Conservation 10: 2023–2043.
Fidler, A.E., van Oers, K., Drent, P.J., Kuhn, S., Mueller, J.C. & Kempenaers, B. 2007. Drd4 gene polymorphisms are associated with personality variation in a passerine bird. Proceedings of the Royal Society B: Biological Sciences 274: 1685–1691.
Fischer, E.F., Recht, S., Vélez, J., Rogge, L., Taubert, A. & Hermosilla, C.R. 2023. Occurrence of gastrointestinal parasites in synanthropic Neozoan Egyptian Geese (Alopochen aegyptiaca, Linnaeus 1766) in Germany. Diversity 15: 388.
Fontaine, A., Reed, E.T., Rodrigue, J. & Giroux, J.F. 2018. Hatch date influences pre-fledging survival of temperate-nesting Canada geese. Wildlife Biology 1: 1–11.
Fox, A.D. 2019. Urban Geese – looking to North America for experiences to guide management in Europe. Wildfowl 69: 3–27.
Fox, A.D. & Abraham, K.F. 2017. Why geese benefit from the transition from natural vegetation to agriculture. Ambio 46: 188– 197.
Fox, A.D. & Kahlert, J. 2000. Do moulting Greylag Geese Anser anser forage in proximity to water in response to food availability and/or quality? Bird Study 47: 266–274.
Fox, A.D., Ebbinge, B.S., Mitchell, C., Heinicke, T., Aarvak, T., Colhoun, K., Clausen, P., Dereliev, S., Farago, S., Koffijberg, K., Kruckenberg, H., Loonen, M.J.J.E., Madsen, J., Mooij, J., Musil, P., Nilsson, L., Pihl, S. & van der Jeugd, H. 2010. Current estimates of goose population sizes in Western Europe, a gap analysis and an assessment of trends. Ornis Svecica 20: 115–127.
Fox, A.D., Flint, P.L., Hohman, W.L. & Savard, J.P.L. 2014. Waterfowl habitat use and selection during the remigial moult period in the northern hemisphere. Wildfowl (Special Issue No. 4): 131–168.
Friesen, L.E., Eagles, P.F.J. & Mackay, R.J. 1995. Effects of residential development on forest dwelling neotropical migrant songbirds. Conservation Biology 9: 1408–1414.
Frigerio, D., Ludwig, S.C., Hemetsberger, J., Kotrschal, K. & Wascher, C.A. 2017. Social and environmental factors modulate leucocyte profiles in free-living Greylag geese (Anser anser). PeerJ 5: e2792.
Frigerio, D., Sumasgutner, P., Kotrschal, K., Kleindorfer, S. & Hemetsberger, J. 2021. From individual to population level: Temperature and snow cover modulate fledging success through breeding phenology in greylag geese (Anser anser). Scientific Reports 11: 16100.
Ganter, B. & Cooke, F. 1996. Pre-incubation feeding activities and energy budgets of Snow Geese: Can food on the breeding grounds influence fecundity? Oecologia 106: 153–165.
Gaston, K.J. (ed.). 2010. Urban Ecology. Oxford University Press, Oxford, UK.
Gil, D. & Brumm, H. (eds.). 2014. Avian Urban Ecology: Behavioural and Physiological Adaptations. Oxford University Press, Oxford, UK.
Gilbert, O. 1989. The Ecology of Urban Habitats. Chapman & Hall, London, UK.
Giles, N. 1992. Wildlife after Gravel: Twenty Years of Practical Research by the Game Conservancy and AR. Game Conservancy, Fordingbridge, UK.
Giles, N. & Street, M. 1990. Management of the feral Greylag and Canada Goose flocks at Great Linford. Game Conservancy Annual Review 21: 116–117.
Gosser, A.L. & Conover, M.R. 1999. Will the availability of insular nesting sites limit reproduction in urban Canada Goose populations? Journal of Wildlife Management 63: 369–373.
Guerena, K.B., Castelli, P.M., Nichols, T.C. & Williams, C.K. 2016. Factors influencing nest survival in resident Canada geese. The Journal of Wildlife Management 80: 1022–1030.
Harrison, A.L., Petkov, N., Mitev, D., Popgeorgiev, G., Gove, B. & Hilton, G.M. 2018. Scale-dependent habitat selection by wintering geese: implications for landscape management. Biodiversity and Conservation 27: 167–188.
Hässler, C. & Halbauer, J. 2004. Die Graugans (Anser anser) als neuer Brutvogel im Gebiet der Stadt Zwickau. Mitteilungen des Vereins Sächsischer Ornithologen 9: 422–424. [In German.]
Hinrichs, S., Berthoud, J.-L. & Woog, F. 2025. Urban Greylag Geese Anser anser nesting on roofs in the city of Hamburg, northern Germany. Wildfowl 75: 108–120.
Hohmann, R. & Woog, F. 2021a. Comparing behavioural responses of Greylag Geese Anser anser and Egyptian Geese Alopochen agyptiaca to disturbance in an urban setting. Wildfowl 71: 244–261.
Hohmann, R. & Woog F. 2021b. How aggressive are Egyptian Geese? Interactions with Greylag Geese and other birds in an urban environment. Wildfowl 71: 234–243.
Hölzinger, J., Maher, U., Bauer, H.G., Bommer, K., Fiedler, W., Konrad, A. & Woog, F. 2018. Anser anser, Grausgans. In J. Hölzinger & H.G. Bauer (eds.), Die Vögel Baden-Württembergs, Nicht-Singvögel 1.2, pp. 179–193. Ulmer Eugen Verlag, Stuttgart, Germany. [In German.]
Johnson I.P. & Sibly R.M. 1993. Pre-breeding behaviour affects condition, assessed by abdominal profile, and hence breeding success of Canada geese Branta canadensis. Wildfowl 44: 60–68.
Kahlert, J. 2006. Factors affecting escape behaviour in moulting Greylag Geese Anser anser. Journal of Ornithology 147: 569–577.
Kampe-Persson, H. 2010. Naturalised geese in Europe. Ornis Svecica 20: 155–173.
Kampp, K. & Preuss, N.O. 2005. The Greylag Geese of Utterslev Mose: a Long-term Population Study of Wild Geese in an Urban Setting. Dansk Ornitologisk Forening, Copenhagen, Denmark.
Käßmann, S. & Woog, F. 2007. How to cope with snow and ice: winter ecology of feral Greylag Geese Anser anser. Wildfowl 57: 29–39.
Käßmann, S. & Woog, F. 2008. Influence of supplementary food on the behaviour of Greylag Geese Anser anser in an urban environment. Wildfowl 58: 46–54.
Keane, E.M. & O’Halloran, J. 1992. The behaviour of a wintering flock of Mute Swans Cygnus olor in southern Ireland. Wildfowl 43: 12–19.
Kestenholz, M. 1994. Body mass dynamics of wintering Tufted Duck Aythya fuligula and Pochard A. ferina in Switzerland. Wildfowl 45: 147–158.
Kleinhenz, A. & Koenig, A. 2018. Home ranges and movements of resident graylag geese (Anser anser) in breeding and winter habitats in Bavaria, South Germany. PLoS One 13(9): e0202443.
Kluen, E., Kuhn, S., Kempenaers, B. & Brommer, J.E. 2012. A simple cage test captures intrinsic differences in aspects of personality across individuals in a passerine bird. Animal Behaviour 84: 279–287.
Koons, D.N., Gunnarsson, G., Schmutz, J.A. & Rotella, J.J. 2014. Drivers of waterfowl population dynamics: from teal to swans. Wildfowl (Special Issue No. 4): 169–191.
Kotrschal, K., Dittami, J., Hirschenhauser, K., Möstl, E. & Peczely, P. 2000. Effects of physiological and social challenges in different seasons on faecal testosterone and corticosterone in male domestic geese (Anser domesticus). Acta Ethologica 2: 115–122.
Krams, I., Suraka, V., Rattiste, K., Abolin¸š-Abols, M., Krama, T., Rantala, M.J., Mierauskas, P., Cirule, D. & Saks, L. 2012. Comparative analysis reveals a possible immunity-related absence of blood parasites in Common Gulls (Larus canus) and Black-headed Gulls (Chroicocephalus ridibundus). Journal of Ornithology 153: 1245–1252.
Kreutzkamp, I. 2003. Die Entwicklung der Brutpopulationen von Graugans (Anser anser), Kanadagans (Branta canadensis) und Nilgans (Alopochen aegyptiacus) im Hamburger Berichtsgebiet von 1990 bis 2002. Hamburger Avifaunistische Beiträge 32: 153–186. [In German.]
Kreuziger, J., Korn, M., Schindler, W. & Stübing, S. 2004. Aktuelle Situation brütender Wasservogelarten in Hessen. Vogel und Umwelt 17: 3–51. [In German].
Kruckenberg, H. 2019. Large-scale egg-dumping by island nesting Greylag Geese Anser anser: an indication of density-dependent regulation in a breeding population in northwest Lower Saxony, Germany? Wildfowl 69: 221–229.
Kurvers, R.H., Eijkelenkamp, B., van Oers, K., van Lith, B., van Wieren, S.E., Ydenberg, R.C. & Prins, H.H. 2009. Personality differences explain leadership in barnacle geese. Animal Behaviour 78: 447–453.
Laursen, K., Kahlert, J. & Frikke, J. 2005. Factors affecting escape distances of staging waterbirds. Wildlife Biology 11: 13–19.
Lebret, T. & Timmerman, A. 1968. A concentration of Greylag Geese (Anser anser) in wing moult in the Netherlands. Limosa 41: 2–17.
Lefebre, E.A. & Raveling, D.G. 1967. Distribution of Canada geese in winter as related to heat loss at varying environmental temperatures. Journal of Wildlife Management 31: 538–546.
Lever, C. 2010. Naturalised Birds of the World. A. & C. Black, London, UK.
Madsen, J. 1986. Danske rastepladser for gæs. Gaasetaellinger 1980–1983. [Status of the staging goose populations and their haunts in Denmark, 1980–1983.] Skov-og Naturstyrelsen, Miljøministeriet, Copenhagen, Denmark. [In Danish with English summary.]
Madsen, J. 1991. Status and trends of goose populations in the Western Palearctic in the 1980s. Ardea 79: 113–122.
Madsen, J. & Fox, A.D. 1995. Impacts of hunting disturbance on waterbirds: a review. Wildlife Biology 1: 193–207.
Madsen, J. & Mortensen, C.E. 1987. Habitat exploitation and interspecific competition of moulting geese in East Greenland. Ibis 129: 25–44.
Madsen, J., Cracknell, G. & Fox, A.D. 1999. Goose Populations of the Western Palearctic: A Review of Status and Distribution. Wetlands International Publications No. 48. Wetlands International, Wageningen, the Netherlands and National Environmental Research Institute, Rönde, Denmark.
Mai, S., Berthoud, J.-L., Haag, H. & Woog, F. 2022. Factors limiting reproductive success in urban Greylag Geese (Anser anser). PeerJ 10: e13685.
Mai, S., Wittor, C., Merker, S. & Woog, F. 2023. DRD4 allele frequencies in greylag geese vary between urban and rural sites. Ecology and Evolution 13(2): e9811.
Marzluff, J.M. 2017. A decadal review of urban ornithology and a prospectus for the future. Ibis 159: 1–13.
Marzluff, J.M., Bowman, R. & Donnelly, R. (eds.). 2001. Avian Ecology and Conservation in an Urbanizing World. Kluwer Academic, Boston, USA.
Marzluff, J.M., Shulenberger, E., Endlicher, W., Alberti, M., Bradley, G., Ryan, C., Zumbrunnen, C. & Simon, U. (eds.). 2008. Urban Ecology: An International Perspective on the Interaction between Humans and Nature. Springer, New York, USA.
Mendel, L.C. 2018. Brutphänologie von Graugänsen (Anser anser L.) im urbanen Lebensraum am Beispiel von Hamburg. Unpublished M.Sc. thesis, University of Hamburg, Germany. [In German with English summary.]
Merling de Chapa, M., Courtiol, A., Engler, M., Giese, L., Rutz, C., Lakermann, M., Müskens, G., van der Horst, Y., Zollinger, R., Wirth, H., Kenntner, N., Krüger, O., Chakarov, N., Müller, A.-K., Looft, V., Grünkorn, T., Hallau, A., Altenkamp, R. & Krone, O. 2020. Phantom of the forest or successful citizen? Analysing how Northern Goshawks (Accipiter gentilis) cope with the urban environment. Royal Society Open Science 7: 201356.
Miranda, A.C., Schielzeth, H., Sonntag, T. & Partecke, J. 2013. Urbanization and its effects on personality traits: a result of microevolution or phenotypic plasticity? Global Change Biology 19: 2634–2644.
Mitchell, C., Hearn, R. & Stroud, D. 2012. The merging of populations of Greylag Geese breeding in Britain. British Birds 105: 498–505.
Møller, A.P. 2009. Successful city dwellers: A comparative study of the ecological characteristics of urban birds in the Western Palearctic. Oecologia 159: 849–858.
Møller, A.P. 2014. Behavioural and ecological predictors of urbanization. In D. Gil & H. Brumm (eds.), Avian Urban Ecology: Behavioural and Physiological Adaptations, pp. 54–68. Oxford University Press, Oxford, UK.
Møller, A.P. & Ibáñez-Álamo, J.D. 2012. Escape behaviour of birds provides evidence of predation being involved in urbanization. Animal Behaviour 84: 341–348.
Owen, M. 1972. Some factors affecting food intake and selection in white-fronted geese. Journal of Animal Ecology 41: 71–92.
Owen, M. & Black, J.M. 1990. Waterfowl Ecology. Chapman & Hall, London, UK.
Owen, M. & Salmon, D.G. 1988. Feral Greylag Geese Anser anser in Britain and Ireland, 1960–86. Bird Study 35: 37–45.
Owen, M., Wells, R.L. & Black, J.M. 1992. Energy budgets of wintering barnacle geese: the effects of declining food resources. Ornis Scandinavica 23: 451–458.
Parris, K. M. 2016. Ecology of Urban Environments. John Wiley & Sons, Oxford, UK.
Pfeffer, K., Fritz, J. & Kotrschal, K. 2002. Hormonal correlates of being an innovative greylag goose, Anser anser. Animal Behaviour 63: 687–695.
Platteeuw, M. & Henkens, R.J. 1997. Possible impacts of disturbance to waterbirds: individuals, carrying capacity and populations. Wildfowl 48: 225–236.
Prop, J. 1991. Food exploitation patterns by Brent Geese during spring staging. Ardea 79: 331–341.
Pulliainen, E. 1963. On the history, ecology and ethology of the Mallards (Anas platyrhynchos L.) overwintering in Finland. Ornis Fennica 40: 46–66.
Ramo, C., Amat, J. A., Nilsson, L., Schricke, V., Rodríguez-Alonso, M., Gómez-Crespo, E., Jubete, F., Navedo J.G., Masero, J.A., Palacios, J., Boos, M. & Green, A.J. 2015. Latitudinal-related variation in wintering population trends of greylag geese (Anser anser) along the Atlantic flyway: A response to climate change? PLoS One 10, e0140181.
Randler, C. 2003. Reactions to human disturbances in an urban population of the Swan Goose Anser cygnoides in Heidelberg (SW Germany). Acta Ornithologica 38: 47–52.
Riegert, J., Fainová, D. & Bystˇrická, D. 2010. Genetic variability, body characteristics and reproductive parameters of neighbouring rural and urban common kestrel (Falco tinnuculus) populations. Population Ecology 52: 73–79.
Rutledge, M.E., Siletzky, R.M., Gu, W., Degernes, L.A., Moorman, C.E., DePerno, C.S. & Kathariou, S. 2013. Characterization of Campylobacter from resident Canada geese in an urban environment. Journal of Wildlife Diseases 49: 1–9.
Ryder, T.B., Reitsma, R., Evans, B. & Marra, P.P. 2010. Quantifying avian nest survival along an urbanization gradient using citizen-and scientist-generated data. Ecological Applications 20: 419–426.
Ryley, K. & Bowler, J.M. 1994. A change of moulting site for Mute Swans Cygnus olor in Gloucestershire. Wildfowl 45: 15–21.
Samia, D.S., Blumstein, D.T., Díaz, M., Grim, T., Ibáñez-Álamo, J.D., Jokimäki, J., Tätte, K., Markó, G., Tryjanowski, P. & Møller, A.P. 2017. Rural-urban differences in escape behavior of European birds across a latitudinal gradient. Frontiers in Ecology and Evolution 5 (Article 66): 1–13.
Schmid, S., Fachet, K., Dinkel, A., Mackenstedt, U. & Woog, F. 2018. Low prevalence of haemosporidian parasites in resident Greylag Geese (Anser anser) in southwestern Germany. Journal of Ornithology 159: 1099–1103.
Schwarz, K. 2010. Ökologie einer expandierenden Grauganspopulation im Ballungsraum. Unpublished diploma thesis, University of Hohenheim, Stuttgart, Germany. [In German.]
Schwarz, K. & Woog, F. 2012. Limits of grazing area use by feral Greylag Geese (Anser anser) during moult. Wildfowl 62: 115–125.
Sears, J. 1989. Feeding activity and body condition of Mute Swans Cygnus olor in rural and urban areas of a lowland river system. Wildfowl 40: 88–98.
Shearer, D.J., Carter, T.C. & O’Neal, B.J. 2022. Canada geese (Branta canadensis) nesting on elevated structures in urban Indiana, USA. Ecology & Evolution 12: e8735.
Shochat, E. 2004. Credit or debit? Resource input changes population dynamics of city-slicker birds. Oikos 106: 622–626.
Soares, L., Escudero, G., Penha, V.A.S. & Ricklefs, R.E. 2016. Low prevalence of haemosporidian parasites in shorebirds. Ardea 104: 129–141.
Sol, D., Blackburn, T., Cassey, P., Duncan, R. & Clavell, J. 2005. The ecology and impact of non-indigenous birds. In J. del Hoyo, A. Elliott & D.A. Christie (eds.), Handbook of the Birds of the World, Vol. 10. Cuckoo-shrikes to Thrushes, pp. 13–35. Lynx Ediciones, Barcelona, Spain.
Sonant, K. & Maestro, D. (eds.). 2006. Baiting and Supplemental Feeding of Game Wildlife Species. The Wildlife Society Technical Review No. 06-1. The Wildlife Society, Bethesda, USA. Available at https://wildlife.org/wp-content/ uploads/2014/05/Baiting06-1.pdf (last accessed 12 June 2025).
Sorace, A. 2002. High density of bird and pest species in urban habitats and the role of predator abundance. Ornis Fennica 79: 60–71.
Sorge, S. 2022. Zu Tode geliebt – Zum Rückgang der Weißwangenganspopulation in München. Vogelwarte 60: 337. [In German.]
Soriano-Redondo, A., Inger, R., Sherley, R.B., Rees, E.C., Abadi, F., McElwaine, G., Colhoun, K., Einarsson, O., Thorstensen, S., Newth, J., Brides, K., Hodgson, D. & Bearhop, S. 2023. Demographic rates reveal the benefits of protected areas in a long-lived migratory bird. PNAS 120 (12): e2212035120.
Stahl, J. 2001. Limits to the co-occurrence of avian herbivores – how geese share scarce resources. Van Denderen bv, Groningen, the Netherlands.
Steiner, W. & Parz-Gollner, R. 2003. Actual numbers and effects of recreational disturbance on the distribution and behaviour of greylag geese (Anser anser) in the Neusiedler See–Seewinkel National Park Area. Journal for Nature Conservation 11: 324–330.
Stope, M.B. 2023. The raccoon (Procyon lotor) as a neozoon in Europe. Animals 13: 273.
Strong, E.A., Redpath, S.M., Montrr´s-Janer, T., Elmberg, J. & Månsson, J. 2021. Seeking greener pastures: crop selection by Greylag Geese (Anser anser) during the moulting season. Ornis Fennica 98: 16–32.
Sutherland, W.J. & Parker G.A. 1985. Distribution of unequal competitors. In R.M. Sibly & R.H. Smith (eds.), Behavioural Ecology – Ecological Consequences of Adaptive Behaviour, pp. 255–273. Blackwell Scientific Publications, Oxford, UK.
Thornton, M., Todd, I. & Roos, S. 2017. Breeding success and productivity of urban and rural Eurasian sparrowhawks Accipiter nisus in Scotland. Ecoscience 24: 115–126.
Timm, K., Mägi, M., Telve, K. & Tilgar, V. 2019. The behavioural response of great tits to novel environment and handling is affected by the DRD4 gene. Ibis 161: 91–100.
United Nations Population Division. 2019. World urbanization prospects: The 2018 revision (ST/ESA/SER.A/420). United Nations, New York, USA.
Väänänen, V.M., Nummi, P., Lehtiniemi, T., Luostarinen, V.M. & Mikkola-Roos, M. 2011. Habitat complementation in urban barnacle geese: from safe nesting islands to productive lawns. Boreal Environment Research 16: 26–34.
Van Dongen, W.F., Robinson, R.W., Weston, M.A., Mulder, R.A. & Guay, P.J. 2015. Variation at the DRD4 locus is associated with wariness and local site selection in urban black swans. BMC Evolutionary Biology 15: 1–11.
Van Oers, K. & Sinn, D.L. 2013. Quantitative and molecular genetics of animal personality. In C. Carere & D. Maestripieri (eds.), Animal Personalities: Behaviour, Physiology, and Evolution, pp. 149–200. University of Chicago Press, Chicago, USA.
Vincze, E., Papp, S., Preiszner, B., Seress, G., Bókony, V. & Liker, A. 2016. Habituation to human disturbance is faster in urban than rural house sparrows. Behavioural Ecology 27: 1304–1313.
Wandeler, P., Funk, S.M., Largiader, C.R., Gloor, S. & Breitenmoser, U. 2003. The city-fox phenomenon: genetic consequences of a recent colonization of urban habitat. Molecular Ecology 12: 647–656.
Wang, S., Zhou, L., Cai, J., Jiang, B. & Xu, W. 2022. Behavioral response of bean goose (Anser fabalis) to simulated ship noises at lake. Animals 12: 465.
Wascher, C.A., Arnold, W. & Kotrschal, K. 2022. Effects of severe anthropogenic disturbance on the heart rate and body temperature in free-living greylag geese (Anser anser). Conservation Physiology 10: coac050.
Wernham, C.V., Toms, M.P., Marchant, J.H., Clark, J.A., Siriwardena, G.M. & Baillie, S.R. (eds.). 2002. The Migration Atlas: Movements of the Birds of Britain and Ireland. T. & A.D. Poyser, London, UK.
Wobeser, G.A. 2007. Disease in Wild Animals. Springer, Berlin, Germany.
Wood, K.A., Ponting, J., D’Costa, N., Newth, J.L., Rose, P.E., Glazov, P. & Rees, E.C. 2017. Understanding intrinsic and extrinsic drivers of aggressive behaviour in waterbird assemblages: a meta-analysis. Animal Behaviour 126: 209–216.
Woog, F. & Schwarz, K. 2024. Urban geese discriminate between predators of different sizes. Wildfowl 74: 193–198.
Woog, F., Schmolz, M. & Lachenmaier, K. 2008. Die Bestandsentwicklung der Graugans (Anser anser) im Stadtkreis Stuttgart. Ornithologische Jahreshefte Baden-Württemberg 24: 141–146. [In German.]
Woog, F., Schwarz, K. & Hulme, M. 2012. All you can eat: do peck rates of Greylag Geese (Anser anser) vary with age and social status? Journal of Ornithology 153: 1025–1029.
Woog, F., Maierhofer, J. & Haag, H. 2013. Endoparasites in the annual cycle of feral Greylag Geese Anser anser. Wildfowl 61: 166–181.
Wüst, W. 1973. Die Vogelwelt des Nymphenburger Parks München. Detlev Kurth, Barmstedt, Germany. [In German.]
Yohannes, E., Križanauskien˙e, A., Valcu, M., Bensch, S. & Kempenaers, B. 2009. Prevalence of malaria and related haemosporidian parasites in two shorebird species with different winter habitat distribution. Journal of Ornithology 150: 287–291.
York, D.L., Cummings, J.L. & Wedemeyer, K.L. 2000. Movements and distribution of radio-collared Canada geese in Anchorage, Alaska. Northwestern Naturalist 81: 11–17.
Zhang, S., Lei, F., Liu, S., Li, D., Chen, C. & Wang, P. 2011. Variation in baseline corticosterone levels of Tree Sparrow (Passer montanus) populations along an urban gradient in Beijing, China. Journal of Ornithology 152: 801–806.
Zillich, U. & Black, J.M. 2014. Body mass and abdominal profile index in captive Hawaiian Geese. Wildfowl 53: 67–77.