Wetlands

, 27:390 | Cite as

Consequences of coastal meadow degradation: The case of the natterjack toad (Bufo Calamita) in Estonia

Article

Abstract

Baltic coastal meadows are among the most threatened habitats in Europe, with most residual habitat being in Estonia and Sweden. We quantitatively related the changes in this habitat type in Estonia to the history of a key inhabitant — the natterjack toad (Bufo calamita Laur.). Between the 1930s and 2000s, 67% of 52 local populations of the toad disappeared; in coastal meadows, the decline was 91%. Since the 1980s, coastal grasslands have lost their value as the main habitat for the species, and occupation of secondary habitats has not balanced the disappearance of primary habitat. According to aerial photographs from 1950–51, 1970–71, and 1996–2000, 60%–83% of the coastal meadow habitats in Estonia were lost by 2000, and the toad became extinct in more than 80% of its historical habitat. The survival of local populations was related to the sizes of managed meadows and sandy areas — larger initial areas were related to better survival, probably due to larger population size. Extinction rates exceeded habitat loss rates during advanced stages of habitat loss after 1970, probably due to the additive effects of habitat fragmentation and the disappearance of critical habitat components. Hence, habitat restoration for natterjack toads should focus on large meadow areas, and should be initiated prior to advance habitat loss. Currently, however, meadow populations of the toad in Estonia are unlikely to persist without artificial re-establishment of populations.

Key Words

amphibians habitat loss habitat management numerical response population history 

Literature Cited

  1. Andren, C. and G. Nilson. 2000. Action plan for the conservation of natterjack toad (Bufo calamita). Tuna Tryck, Eskilstuna, Sweden.Google Scholar
  2. Arntzen, J. and J. Boomsma. 1985. Abundance, growth and feeding of natterjack toads (Bufo calamita) in 4-year old artificial habitat. Journal of Applied Ecology 22: 395–405.CrossRefGoogle Scholar
  3. Aul, J. 1936. Records about amphibians in Pärnu County. Eesti Loodus 3: 98–101.Google Scholar
  4. Banks, B. and T. J. C. Beebee. 1987. Spawn predation and larval growth inhibition as mechanisms for niche separation in anurans. Oecologia 72: 569–73.CrossRefGoogle Scholar
  5. Bardsley, L. and T. J. C. Beebee. 2000. Competition between Bufo larvae in a eutrophic pond. Oecologia 124: 33–39.CrossRefGoogle Scholar
  6. Beebee, T. J. C. 1979. A review of scientific information pertaining to the natterjack toad Bufo calamita throughout its geographical range. Biological Conservation 16: 107–34.CrossRefGoogle Scholar
  7. Beebee, T. J. C. 1983. The Natterjack Toad. Oxford, UK.Google Scholar
  8. Beebee, T. J. C. 2002. The natterjack toad (Bufo calamita) in Ireland: current status and conservation requirements. Irish Wildlife Manuals 10.Google Scholar
  9. Beebee, T. J. C. and J. S. Denton. 1996. Natterjack Toad Conservation Handbook. Cityprint, Peterborough, UK.Google Scholar
  10. Beebee, T. J. C. and R. A. Griffiths. 2005. The amphibian decline crisis: a watershed for conservation biology? Biological Conservation 125: 271–85.CrossRefGoogle Scholar
  11. Beintema, A. J. 1991. What makes a meadow bird a meadow bird? Wader Study Group Bulletin 61 (supplement): 3–5.Google Scholar
  12. Blaustein, A. R. and J. M. Kiesecker. 2002. Complexity in conservation: lessons from the global decline of amphibian populations. Ecology Letters 5: 597–608.CrossRefGoogle Scholar
  13. Briggs, L. 2004. Restoration of breeding sites for threatened toads on coastal meadows. p. 34–43. In R. Rannap, L. Briggs, K. Lotman, I. Lepik, and V. Rannap (eds.) Coastal Meadow Management. Prisma Print, Tallinn, Estonia.Google Scholar
  14. Buckley, J. and T. J. C. Beebee. 2004. Monitoring the conservation status of an endangered amphibian: the natterjack toad Bufo calamita in Britain. Animal Conservation 7: 221–28.CrossRefGoogle Scholar
  15. Carr, L. W. and L. Fahrig. 2001. Effect of road traffic on two amphibian species of different vagility. Conservation Biology 15: 1071–78.CrossRefGoogle Scholar
  16. Collins, J. P. and A. Storfer. 2003. Global amphibian declines: sorting the hypotheses. Diversity and Distributions 9: 89–98.CrossRefGoogle Scholar
  17. Cushman, S. A. 2006. Effects of habitat loss and fragmentation on amphibians: a review and prospectus. Biological Conservation 128: 321–40.CrossRefGoogle Scholar
  18. Denton, J. S. and T. J. C. Beebee. 1996. Habitat occupancy by juvenile natterjack toads (Bufo calamita) on grazed and ungrazed heathland. Herpetological Journal 6: 49–52.Google Scholar
  19. Denton, J. S., S. P. Hitchings, T. J. C. Beebee, and A. Gent. 1997. A recovery program for the natterjack toad (Bufo calamita) in Britain. Conservation Biology 11: 1329–38.CrossRefGoogle Scholar
  20. Ernits, P. 1993. Natterjack toads (Bufo calamita Laur.) on the islands and the shore of the Gulf of Riga. The Yearbook of the Estonian Naturalists’ Society 73: 153–76.Google Scholar
  21. Fahrig, L. 2003. Effects of habitat fragmentation on biodiversity. Annual Reviews in Ecology and Systematics 34: 487–515.CrossRefGoogle Scholar
  22. Fog, K. 1988. Reinvestigation of 1300 amphibian localities recorded in the 1940s. Memoranda Societatis pro Fauna et Flora Fennica 64: 94–96.Google Scholar
  23. Funk, W. C., A. E. Greene, P. S. Corn, and F. W. Allendorf. 2005. High dispersal in a frog species suggests that it is vulnerable to habitat fragmentation. Biological Letters 1: 13–16.CrossRefGoogle Scholar
  24. Günther, R. and F. Meyer. 1996. Kreuzkröte (Bufo calamita Laurenty, 1768). Die Amphibien and Reptilien Deutschlands. Gustav Fischer Verlag, Jena, Germany.Google Scholar
  25. Hellström, M. and Å. Berg. 2001. Effects of restoration and management regime on the avifaunal composition on Swedish wet meadows. Ornis Svecica 11: 235–52.Google Scholar
  26. Hosmer, D. W. and S. Lemeshow. 1989. Applied Logistic Regression. John Wiley & Sons, Inc., New York, NY, USA.Google Scholar
  27. Jutila, H. 2001. How does grazing by cattle modify the vegetation of coastal grasslands along the Baltic Sea? Annales Botanici Fennici 38: 181–200.Google Scholar
  28. Kauri, H. 1947. Die verbreitung der amphibien und reptilien in Estland. Kungliska Fysiografiska Sällskapets i Lund Förhandlingar 16: 1–20.Google Scholar
  29. Kennish, M. J. 2001. Coastal salt systems in the U.S.: a review of anthropogenic impacts. Journal of Coastal Research 17: 731–48.Google Scholar
  30. Koivula, K. and A. Rönkä. 1998. Habitat deterioration and efficiency of antipredator strategy in a meadow-breeding wader, Temminck’s stint (Calidris temminckii). Oecologia 116: 348–55.CrossRefGoogle Scholar
  31. Kuresoo, A. and E. Mägi. 2004. Changes of bird communities in relation to management of coastal meadows in Estonia. p. 52–61. In R. Rannap, L. Briggs, K. Lotman, I. Lepik, and V. Rannap (eds.) Coastal Meadow Management. Prisma Print, Tallinn, Estonia.Google Scholar
  32. Luhamaa, H., I. Ikonen, and T. Kukk. 2001. Seminatural communities of Läänemaa County, Estonia. Society of Protection of Seminatural Communities, Tartu — Turku, Estonia.Google Scholar
  33. Marsh, D. M. 2001. Fluctuations in amphibian populations: a meta-analysis. Biological Conservation 101: 327–35.CrossRefGoogle Scholar
  34. McGarigal, K. and S. A. Cushman. 2002. Comparative evaluation of experimental approaches to the study of habitat fragmentation effects. Ecological Applications 12: 335–45.CrossRefGoogle Scholar
  35. Milsom, T. P., J. D. Hart, W. K. Parkin, and S. Peel. 2002. Management of coastal grazing marshes for breeding waders: the importance of surface topography and wetness. Biological Conservation 103: 199–207.CrossRefGoogle Scholar
  36. Myklestad, Å. and M. Sætersdal. 2004. The importance of traditional meadow management techniques for conservation of vascular plant species richness in Norway. Biological Conservation 118: 133–39.CrossRefGoogle Scholar
  37. Ottvall, R. and H. G. Smith. 2006. Effects of an agri-environment scheme on wader populations of coastal meadows of southern Sweden. Agriculture, Ecosystems and Environment 113: 264–71.CrossRefGoogle Scholar
  38. Paal, J. 1998. Rare and threatened plant communities of Estonia. Biodiversity and Conservation 7: 1027–49.CrossRefGoogle Scholar
  39. Rannap, R. 2004. Boreal Baltic coastal meadow management for Bufo calamita. p. 26–33. In R. Rannap, L. Briggs, K. Lotman, I. Lepik, and V. Rannap (eds.) Coastal Meadow Management. Prisma Print, Tallinn, Estonia.Google Scholar
  40. Ratt, A. 1985. Some facts about agricultural development over the decades in Estonia. Valgus, Tallinn, Estonia.Google Scholar
  41. Sinsch, U. 1997. Postmetamorphic dispersal and recruitment of first breeders in a Bufo calamita metapopulation. Oecologia 112: 42–47.CrossRefGoogle Scholar
  42. Sinsch, U. 1998. Biologie und Ökologie der Kreuzkröte. Laurenti Verlag, Bochum, Germany.Google Scholar
  43. Sits, E. 1933. Some notes about the natterjack toad. Eesti Loodus 3: 62–64.Google Scholar
  44. Soikkeli, M. and J. Salo. 1979. The bird fauna of abandoned shore pastures. Ornis Fennica 56: 124–132.Google Scholar
  45. Stephan, T., K. Ulbrich, W.-R. Grosse, and F. Meyer. 2001. Modelling the extinction risk of isolated populations of natterjack toad Bufo calamita. Web Ecology 2: 47–56.Google Scholar
  46. Stuart, S. N., J. S. Chanson, N. A. Cox, B. E. Young, A. S. L. Rodrigues, D. L. Fischman, and R. W. Waller. 2004. Status and trends of amphibian declines and extinctions worldwide. Science 306: 1783–86.CrossRefPubMedGoogle Scholar
  47. Thorup, O. 2004. Suitable habitat management for Danish bird populations. p. 44–51. In R. Rannap, L. Briggs, K. Lotman, I. Lepik, and V. Rannap (eds.) Coastal Meadow Management. Prisma Print, Tallinn, Estonia.Google Scholar
  48. Vinther, E. and H. Tranberg. 1999. Naturkvalitet i strandenge i Fyns Amt før og efter 1980. Fyns Amt, Odense, Denmark.Google Scholar
  49. Williams, G. and M. Hall. 1987. The loss of coastal grazing marshes in South and East England, with special reference to East Essex, England. Biological Conservation 39: 243–53.CrossRefGoogle Scholar

Copyright information

© Society of Wetland Scientists 2007

Authors and Affiliations

  1. 1.Institute of Zoology and Hydrobiology Centre of Basic and Applied EcologyUniversity of TartuTartuEstonia
  2. 2.Ministry of the EnvironmentTallinnEstonia
  3. 3.Faculty of Mathematics and Natural SciencesUniversity of TallinnTallinnEstonia

Personalised recommendations