„Velké druhy" racků je označení zahrnující racky z druhového komplexu racka bělohlavého (Larus cachinnans), racka středomořského (L. michahelis) a racka stříbřitého (L. argentatus). Jejich populace v Evropě a Severní Americe za posledních ca 50 let značně narostly. Šíření tak oportunistických druhů vyvolalo obavy z jejich možného negativního vlivu na biodiverzitu, početnost a hnízdní úspěšnost jiných druhů vodního ptactva. Naskýtá se otázka, zda je vhodné začít velké druhy racků na našem území potlačovat, a pokud ano, jaká opatření by bylo vhodné zavést.
Použitá a citovaná literatura:
Benko Š. & Chudý A., 2011: Chránené vtáčie územie Dubnické štrkovisko. Slovenská ornitologická spoločnosť/BirdLife Slovensko, Bratislava: 77 pp.
BirdLife International, 2015: IUCN Red List for birds. http://www.birdlife.org
Blokpoel H. & Spaans A.L., 1991: Superabundance in gulls, causes, problems and solutions. Acta XX congressus internationalis ornithologici. New Zealand Ornithological Congress Trust Board.
Blokpoel H., Tessier G.D. & Andress R.A., 1997: Successful Restoration of the Ice Island Common Tern Colony Requires On-going Control of Ring-billed Gulls. Colonial Waterbirds 20(1): 98-101.
Booth V. & Morrison P., 2010: Effectiveness of disturbance methods and egg removal to deter large gulls Larus spp. from competing with nesting terns Sterna spp. on Coquet Island RSPB reserve, Northumberland, England. Conservation Evidence 7: 39-43.
Bosch M., 1996: The Effects of Culling on Attacks by Yellow-legged Gulls (Larus cachinnans) Upon Three Species of Herons. Colonial Waterbirds 19(2): 248-252.
Bosch M., Oro D., Cantos F.J. & Zabala M., 2000: Short-term effects of culling on the ecology and population dynamics of the yellow-legged gull. Journal of Applied Ecology 37(2): 369-385.
Chudý A., 2009: Hniezdenie rybára riečneho (Sterna hirundo) na Slovensku, faktory ovplyvňujúce početnosť, hniezdnu úspešnosť a návrhy manažmentu. Diplomová práca, PRIF UK, Bratislava: 41 pp.
Chytil J. & Macháček P., 2000: Vývoj hnízdní populace rackovitých (Laridae) a rybákovitých (Sternidae) na nejjižnější Moravě. Sylvia 36/2: 113-126.
Coulson J.C., Duncan N. & Thomas C., 1982: Changes in the breeding biology of the Herring gull (Larus argentatus) induced by reduction in the size and density of the colony. Journal of Animal Ecology 51: 739-756.
Danko Š., Darolová A. & Krištín A. (eds.), 2002: Rozšírenie vtákov na Slovensku. Veda. Bratislava: 688 pp.
Duncan N., 1978: The effects of culling Herring gulls (Larus argentatus) on recruitment and population dynamics. Journal of Applied Ecology 15: 697-713.
EIONET, 2014: Larus cachinnans. Birds Directive: Report on Implementation Measures. Article 12 reporting for the period 2008 - 2012 (second delivery).
http://cdr.eionet.europa.eu/Converters/run_conversion?file=sk/eu/art12/envuyluvw/SK_birds_reports-14314-132352.xml&conv=343&source=remote#A459_B
Finney S.K., Harris M.P., Keller L.F., Elston D.A., Monaghan P. & Wanless S., 2003: Reducing the density of breeding gulls influences the pattern of recruitment of immature Atlantic puffins Fratercula arctica to a breeding colony. Journal of Applied Ecology 40: 545-552.
Gwiazda R., Bukaciński D., Neubauer G., Faber M., Betleja J., Zagalska-Neubauer M., Bukacińska M. & Chylarecki P., 2011: Diet composition of the Caspian
Gull (Larus cachinnans) in inland Poland: effects of breeding area, breeding stage and sympatric breeding with the Herring Gull (Larus argentatus). Ornis Fennica 88: 80-89.
Hario M., 1994: Reproductive performance of the nominate Lesser Black-backed Gull under the pressure of Herring Gull predation. Ornis Fennica 71: 1-10.
Harris M.P. & Wanless S., 1997: The effect of removing large number of gulls Larus spp. on an island population of Oystercatchers Haematopus ostralegus: implications for management. Biological Conservation 82: 167-171.
Herrmann C., 2009: Das „Möwenproblem“ im 20. Jahrhundert: Eine Darstellung der historischen Entwicklung in Deutschland sowie der Bestandslenkung an der Ostseeküste der DDR. Vogelwelt 130: 25-47.
Hudec K. & Štastný K. (eds.), 2005: Fauna ČR. Svazek 29/2. Ptáci–Aves. Díl II/2. Academia. Praha: 1203 pp.
Keller V. & Zbinden N., 1998: Die Weisskopfmöwe Larus cachinnans in der Schweiz: ein Problem für andere Vögel? Der Ornithologische Beobachter 95: 311-324.
Kress S.W., 1983: The Use of Decoys, Sound Recordings, and Gull Control for Re-establishing a Tern Colony in Maine. Colonial Waterbirds 6: 185-196.
Kress S., 2000: Colony site management techniques. Waterbird Conservation for the Americas. http://www.waterbirdconservation.org/plan/rpt-sitemanagement.pdf
Macháček P., 2010: Racek bělohlavý (Larus cachinnans). RegioM. Sborník regionálního muzea v Mikulově: 24-27.
Macháček P., Chytil J. & Šebela M., 2012: Ptáci Vodního díla Nové Mlýny. MŽP ČR, Praha: 116 pp.
Martínez-Abraín A., 2000: What is the effectiveness of culling to reduce population growth rates of gull colonies? Systematic review no. 26. Consultation draft review protocol. Centre for Evidence-based Conservation: 11 pp.
http://www.cebc.bangor.ac.uk/Documents/DRAFT%20Protocol26%20Gull%20culling.pdf (Pozn.: práca nebola dokončená, je k dispozícii iba vo forme draftu)
Morrison P. & Allcorn R.I., 2006: The effectiveness of different methods to deter large gulls Larus spp. from competing with nesting terns Sterna spp. on Coquet Island RSPB reserve, Northumberland, England. Conservation Evidence 3: 84-87.
Oro D. & Martínez-Abraín A., 2007: Deconstructing myths on large gulls and their impact on threatened sympatric waterbirds. Animal Conservation 10: 117-126.
Oro D., de León A., Minguez E. & Furness W., 2005: Estimating predation on breeding European storm-petrels (Hydrobates pelagicus) by yellow-legged gulls (Larus michahellis). Journal of Zoology 265: 421-429.
Sadoul N., Johnson A.R., Walmsley J.G. & Levêque R., 1996: Changes in the numbers and the distribution of colonial charadriformes breeding in the Camargue, southern France. Colonial Waterbirds 19: 46–58.
Sanz-Aguilar A., Martínez-Abraín A., Tavecchia G., Mínguez E. & Oro D., 2009: Evidence-based culling of a facultative predator: Efficacy and efficiency components. Biological Conservation 142: 424-431.
Scotland´s National Nature Reserves, s.a.: The story of the Isle of May National Nature Reserve, pp. 33. http://www.snh.org.uk/pdfs/publications/nnr/ The_Story_of_the_Isle_ of_May_National_ Nature_Reserve.pdf
Slovenská ornitologická spoločnosť/BirdLife Slovensko: Čajka bielohlavá, Larus cachinnans,http://atlas.vtaky.sk/atlasvtakov.php?id=druh&num=05_6, 17.02.2015
Skórka P., Wójcik J.D. & Martyka R., 2005: Colonization and population growth of Yellow-legged Gull Larus cachinnans in southeastern Poland: causes and influence on native species. Ibis 147: 471-482.
Skórka P., Wójcik J.D., Martyka R. & Lenda M., 2012: Numerical and behavioural response of Black-headed Gull Chroicocephalus ridibundus on population growth of the expansive Caspian Gull Larus cachinnans. Journal of Ornithology 153: 947-961.
Smith G.C. & Carlile N., 1993: Methods for population control within a silver gull colony. Wildlife Research 20(2): 219-225.
Thomas G.J., 1972: A review of gull damage and management methods at nature reserves. Biological Conservation 4(2): 117-127.
Vidal E., Médail F. & Tatoni T., 1998: Is the yellow-legged gull a superabundant bird species in the Mediterranean? Impact on fauna and flora, conservation measures and research priorities. Biodiversity and Conservation 7: 1013-1026.
Wanless S., Harris M.P., Calladine J. & Rothery P., 1996: Modelling responses of Herring Gull and Lesser Black-backed Gull populations to reduction of reproductive output: implications for control measures. Journal of Applied Ecology 33: 1420-1432.
The populations of „large gulls“ from the species complex Larus cachinnans, L. michahelis and L. argentatus have undergone a widespread demographic increase in the last 50 years, particularly in Europe and North America. The spread of such opportunistic species can negatively influence biodiversity and the breeding success of other bird species breeding at the same site. The question of population control and different methods used is nowadays also a frequently discussed topic in the Czech and Slovak Republics.