The efficacy of culling seals seen preying on seabirds as a means of reducing seabird mortality

African Journal of Ecology

Volumn 47, Issue 3, 2009, Pages 335-340

  Makhado, Azwianewi B ^a,b   Meÿer, Mike A ^a   Crawford, Robert J M ^a   Underhill, Les G ^b   Wilke, Chris ^a  

^a MARINE AND COASTAL MANAGEMENT   (South Africa)

^b UNIVERSITY OF CAPE TOWN   (South Africa)

Author keywords

Arctocephalus pusillus; Cape fur seal; Cape gannet; Culling; Fledgling mortality; Morus capensis; Predation

Indexed keywords

BREEDING SEASON; FLEDGING; MORTALITY; PINNIPED; PREDATION; PREDATOR CONTROL; SEABIRD;

AFRICA; MALGAS ISLAND; SOUTH AFRICA; SOUTHERN AFRICA; SUB-SAHARAN AFRICA; WESTERN CAPE;

ANIMALIA; ARCTOCEPHALUS PUSILLUS; ARCTOCEPHALUS PUSILLUS PUSILLUS; MORUS (PLANT); MORUS CAPENSIS;

EID: 69049104466     PISSN: 01416707     EISSN: 13652028     Source Type: Journal    
DOI: 10.1111/j.1365-2028.2008.00966.x     Document Type: Article

References (39)

1. American Society of Mammalogists (1967) Standard measurements of seals. J. Mammal. 48, 459 462.
2. Apps, P. (2000) Smither's Mammals of Southern Africa: Field Guide. Struik, Cape Town.
3. Batchelor, A.L. Ross, G.J.B. (1984) The diet and implications of dietary change of Cape gannets on Bird Island, Algoa Bay. Ostrich 55, 45 63.
4. Butterworth, D.S., Punt, A.E., Oosthuizen, W.H. Wickens, P.A. (1995) The effects of future consumption by the Cape fur seal on catches and catch rates of the Cape hakes. 3. Modeling the dynamics of the Cape fur seal Arctocephalus pusillus pusillus. S. Afr. J. Mar. Sci. 16, 161 183.
5. Castellini, M.A. Calkins, D.G. (1993) Mass estimates using body morphology in Steller sea lions. Mar. Mamm. Sci. 9, 48 54.
6. Castellini, M.A. Kooyman, G.L. (1990) Length, girth and mass relationships in Weddel seals (Leptonychotes weddellii). Mar. Mamm. Sci. 6, 75 77.
7. Caughley, G. (1981) Overpopulation. In : Problems in Management of Locally Abundant Wild Mammals (Eds P. A. Jewell, S. Holt D. Hart). Academic Press, New York.
8. Crawford, R.J.M., David, J.H.M., Williams, A.J. Dyer, B.M. (1989) Competition for space: recolonising seals displace endangered, endemic seabirds off Namibia. Biol. Conserv. 48, 59 72.
9. David, J.H.M., Cury, P., Crawford, R.J.M., Randall, R.M., Underhill, L.G. Meÿer, M.A. (2003) Assessing conservation priorities in the Benguela ecosystem, South Africa: analysing predation by seals on threatened seabirds. Biol. Conserv. 114, 289 292.
10. Du Toit, M., Bartlett, P.A., Bester, M.N. Roux, J.-P. (2004) Seal-seabird predation at Ichaboe Island, Namibia: prey selection by individual seals. S. Afr. J. Wildl. Res. 34, 45 54.
11. Fraker, M.A. Mate, B.R. (1999) Seals, sea lions, and salmon in the Pacific Northwest. In : Conservation and Management of Marine Mammals (Eds J. R. Twiss Jr. R. R. Reeves). Smithsonian Institution Press, Washington, DC.
12. Garrott, R.A., White, P.J. White, C.A.V. (1993) Overabundance: an issue for conservation biologists? Conserv. Biol. 7, 946 949.
13. Goodrich, J.M. Buskirk, S.W. (1995) Control of abundant native vertebrates for conservation of endangered species. Conserv. Biol. 9, 1357 1364.
14. Harris, S. Saunders, G. (1993) The control of canid populations. Symp. Zool. Soc. Lond. 65, 441 464.
15. Hockey, P.A.R., Dean, W.R.J. Ryan, P.G. (2005) Roberts Birds of Southern Africa, 7th edn. John Voelcker Bird Book Fund, Cape Town.
16. Jarvis, M.J.F. (1974) The ecological significance of clutch size in the South African gannet (Sula capensis (Lichtenstein)). J. Anim. Ecol. 43, 1 17.
17. Jenks, S.M. Wayne, R.K. (1992) Problems and policy for species threatened by hybridization: the red wolf as a case study. In : Wildlife 2001: Populations (Eds D. R. McCullough R. H. Barrett). Elsevier Applied Science, New York.
18. Jewell, P.A., Holt, S. Hart, D., Eds 1981) Problems in Management of Locally Abundant Wild Mammals. Academic Press, New York.
19. Kirkman, S.P., Oosthuizen, W.H., Meÿer, M.A., Kotze, P.G.H., Roux, J.-P. Underhill, L.G. (2007) Making sense of censuses - dealing with missing data: trends in pup counts of Cape fur seal Arctocephalus pusillus pusillus for the period 1972- 2004. Afr. J. Mar. Sci. 29, 161 176.
20. Lavigne, D.M. (2003) Marine mammals and fisheries: the role of science in the culling debate. In : Marine Mammals: Fisheries, Tourism and Management Issues (Eds N. Gales, M. Hindell R. Kirkwood). CSIRO Publishing, Collingwood, Australia.
21. Makhado, A.B., Crawford, R.J.M. Underhill, L.G. (2006) Impact of predation by Cape fur seals Arctocephalus pusillus on Cape gannets Morus capensis at Malgas Island, Western Cape, South Africa. Afr. J. Mar. Sci. 28, 681 687.
22. Marine Mammal Commission (2000) Annual Report to Congress 1999. Marine Mammal Commission, Maryland.
23. Marks, M.A., Brooke, R.K. Gildenhuys, A.M. (1997) Cape fur seal Arctocephalus pusillus predation on Cape cormorants Phalacrocorax capensis and other birds at Dyer Island, South Africa. Mar. Ornithol. 25, 9 12.
24. McCullough, D.R. Barrett, R.H. (1992) Wildlife 2001: Populations. Elsevier Applied Science, New York.
25. Mecenero, S., Kirkman, S.P. Roux, J.-P. (2005) Seabirds in the diet of Cape fur seals Arctocephalus pusillus pusillus at three mainland breeding colonies in Namibia. Afr. J. Mar. Sci. 27, 509 512.
26. Miller, C.M., Oosthuizen, W.H. Wickens, P.A. (1996) Cape fur seals trapped in trawling gear: age structure, sex ratio, seasonality and distribution. S. Afr. J. Mar. Sci. 17, 105 111.
27. National Marine Fisheries Service (1996) Environmental assessment on conditions for lethal removal of California sea lions at the Ballard Locks to protect winter steelhead. NMFS Environ. Assess. Rep. 1 81.
28. National Oceanic and Atmospheric Administration (1996) National Marine Fisheries Service OK's Permanent Home for Seattle's Sea Lions at Sea World in Florida. NOAA, Available at: http://www.publicaffairs.noaa.gov/pr96/apr96/ noaa96-r130.html.
29. National Oceanic and Atmospheric Administration (1999) Steelhead-eating Sea Lions All But Gone from Seattle's Ballard Locks. NOAA, Available at: http://www.publicaffairs.noaa.gov/releases99/may99/noaa99r128.html.
30. Navarro, R.A. (1991) Food addition and twinning experiments in the Cape gannet: effects on breeding success and chick growth and behavior. Colon. Waterbirds 14, 92 102.
31. Navarro, R.A. (2000) Cape fur seal predation on Cape gannet fledglings. Bird Numbers 9, 15 16.
32. Rebelo, A.G. (1984) Cape fur seal Arctocephalus pusillus kills jackass penguin Spheniscus demersus on land. Cormorant 12, 111.
33. Reid, W.V. Miller, K.R. (1989) Keeping Options Alive: The Scientific Basis for Conserving Biodiversity. World Research Institute, Washington, DC.
34. Shaughnessy, P.D. (1978) Cape fur seals preying on seabirds. Comorant 5, 31.
35. Shaughnessy, P., Semmelink, A., Cooper, J. Frost, P. (1981) Attempts to develop acoustic methods of keeping Cape fur seals, Arctocephalus pusillus, from fishing nets. Biol. Conserv. 21, 141 158.
36. Wagner, F.H. Seal, U.S. (1992) Values, problems, and methodologies in managing overabundant wildlife populations: an overview. In : Wildlife 2001: Populations (Eds D. R. McCullough R. H. Barrett). Elsevier Scientific Publications, London.
37. Wickens, P.A., Japp, D.W., Shelton, P.A., Kriel, F., Goosen, P.C., Rose, B., Augustyn, C.J., Bross, C.A.R., Penney, A.J. Krohn, R.G. (1992) Seals and fisheries in South Africa - competition and conflict. In : Benguela Trophic Functioning (Eds A. I. L. Payne, K. H. Brink, K. H. Mann R. Hilborn). S. Afr. J. Mar. Sci. 12, 773 789.
38. World Conservation Monitoring Centre (1992) Global Biodiversity: Status of the Earth's Living Resources. Chapman and Hall, London.
39. Yodzis, P. (2001) Must top predators be culled for the sake of fisheries? Trends Ecol. Evol. 16, 78 84.