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acta ethologica

, Volume 13, Issue 2, pp 93–100 | Cite as

Killing of Cape fur seal (Arctocephalus pusillus pusillus) pups by brown hyenas (Parahyaena brunnea) at mainland breeding colonies along the coastal Namib Desert

  • Ingrid WieselEmail author
Original Paper

Abstract

Brown hyenas (Parahyaena brunnea) scavenge and kill seal pups at mainland Cape fur seal (Arctocephalus pusillus pusillus) colonies. The prey encounter interval and interval between kills depended on seal density, and increased density resulted in an increase of the capture rate and increase in hunting efficiency from 14% in November to 47% in January. The time brown hyenas spent at the seal colony decreased with increasing seal density and increasing air temperatures. Nevertheless, they were regularly active during the day when less adult seals were present at the colony, which indicates that the attendance of adult seals might play a role in the choice of foraging time. Brown hyenas killed seal pups throughout the study period. The predation rate was independent of the availability of non-violent mortalities, but the absolute number of kills was positively density-dependent. Mass kill events were recorded throughout the study period and are therefore not unusual occurrences. The overabundance of easy and vulnerable prey may lead to an over stimulus situation that triggers killing independent of the consumption of the prey or the hunger state.

Keywords

Optimal foraging Predation Surplus kill Cape fur seal Brown hyena 

Notes

Acknowledgments

Financial support for the study was given by the graduate scholarship of the University of Hamburg, the German Academic Exchange Service (DAAD), and the Namdeb Diamond Corporation (Ltd.) Pty in Namibia. I also thank Dr. Jean-Paul Roux for his inspiration. The study was conducted under a research permit, issued by the Namibian Ministry of Environment and Tourism. Two anonymous reviewers provided helpful comments to improve the quality of the manuscript.

References

  1. Altmann J (1974) Observational study of behaviour: sampling methods. Behaviour 49:227–267CrossRefPubMedGoogle Scholar
  2. Caughley G (1977) Analysis of vertebrate populations. Wiley, TorontoGoogle Scholar
  3. Charnov EL (1976) Optimal foraging, the marginal value theorem. Theor Popul Biol 9:129–136CrossRefPubMedGoogle Scholar
  4. Cook RM, Cockrell BJ (1978) Predator ingestion rate and its bearing on feeding time and the theory of optimal diets. J Anim Ecol 47:529–547CrossRefGoogle Scholar
  5. Curio E (1976) The ethology of predation. Springer, BerlinGoogle Scholar
  6. Darimont CT, Reimchen TE, Paquet PC (2003) Foraging behaviour by gray wolves on salmon streams in coastal British Columbia. Can J Zool 81:349–353CrossRefGoogle Scholar
  7. David JHM, Rand RW (1986) Attendance behavior of South African fur seals. In: Gentry RL, Kooymann GL (eds) Fur seals: maternal strategies on land and at sea. Princeton University Press, Princeton, pp 126–141Google Scholar
  8. De Villiers DJ, Roux J-P (1992) Mortality of newborn pups of the South African fur seal Arctocephalus pusillus pusillus in Namibia. S Afr J Marine Sci 12:881–889Google Scholar
  9. Ebensperger LA, Hurtado MJ (2005) Seasonal changes in the time budget of degus, Octodon degus. Behaviour 142:91–112CrossRefGoogle Scholar
  10. Emlen JM (1966) The role of time and energy in food preference. Am Nat 100:611–617CrossRefGoogle Scholar
  11. Estes D (1967) Predators and scavengers. Nat Hist 76:20–29Google Scholar
  12. Gende SM, Quinn TP (2004) The relative importance of prey density and social dominance in determining energy intake by bears feeding on Pacific salmon. Can J Zool 82:75–85CrossRefGoogle Scholar
  13. Geraci JR, Lounsbury VJ (1993) Specimen and data collection. In: Geraci JR, Lounsbury VJ (eds) Marine mammals ashore: a field guide for strandings. Texas A&M Sea Grant Publication, Galveston, pp 175–228Google Scholar
  14. Goethe F (1956) Fuchs, Vulpes vulpes (Linné, 1758) reibt Schlafgesellschaft von etwa sechzig jugendlichen Silbermöwen (Larus argentatus Pontopp.) auf. Säugetierk Mitt 4:58–60Google Scholar
  15. Goss R (1986) The influence of food source on the behavioural ecology of brown hyaenas Hyaena brunnea in the Namib Desert. Unpublished MSc thesis, University of Pretoria, PretoriaGoogle Scholar
  16. Hills TT, Adler FR (2002) Time’s crooked arrow: optimal foraging and rate-biased time perception. Anim Behav 64:589–597CrossRefGoogle Scholar
  17. Jędrzejewska B, Jędrzejewski W (1989) Seasonal surplus killing as hunting strategy of weasels Mustela nivalis—test of a hypothesis. Acta Theriol 34:347–359Google Scholar
  18. Kossak S (1989) Multiple hunting by lynx and red fox and utilization of prey by some carnivores. Acta Theriol 34:505–512Google Scholar
  19. Kruuk H (1964) Predators and anti-predator behaviour of the black-headed gull (Larus ridibundus L.). Behaviour (Suppl) 11:1–148Google Scholar
  20. Kruuk H (1972a) The spotted hyena: a study of predation and social behavior. University of Chicago Press, ChicagoGoogle Scholar
  21. Kruuk H (1972b) Surplus killing by carnivores. J Zool 166:233–244CrossRefGoogle Scholar
  22. Kruuk H (1976) Feeding and social behaviour of the striped hyaena (Hyaena vulgaris Desmarest). E Afr Wildl J 14:91–111Google Scholar
  23. MacArthur RH, Pianka ER (1966) On optimal use of a patchy environment. Am Nat 100:603–609CrossRefGoogle Scholar
  24. Macdonald DW (1976) Food caching by red foxes and some other carnivores. Z Tierpsychol 42:170–185CrossRefPubMedGoogle Scholar
  25. Mills MGL (1978) Foraging behaviour of the brown hyaena (Hyaena brunnea Thunberg, 1820) in the Southern Kalahari. Z Tierspychol 48:113–141CrossRefGoogle Scholar
  26. Mills MGL (1984) The comparative behavioural ecology of the brown hyaena Hyaena brunnea and the spotted hyaena Crocuta crocuta in the Southern Kalahari. Koedoe (Suppl) 27:237–247Google Scholar
  27. Mills MGL (1990) Kalahari hyenas: the comparative behavioral ecology of two species. Chapman & Hall, LondonGoogle Scholar
  28. Mills MGL, Mills MEJ (1978) The diet of the brown hyaena Hyaena brunnea in the Southern Kalahari. Koedoe 21:125–149Google Scholar
  29. Oksanen T (1983) Prey caching in the hunting strategy of small mustelids. Acta Zool Fennica 174:197–199Google Scholar
  30. Oksanen T, Oksanen L, Fretwell SD (1985) Surplus killing in the hunting strategy of small predators. Am Nat 126:328–346CrossRefGoogle Scholar
  31. Ono KA, Boness DJ (1991) The influence of El Niño on mother–pup behavior, pup ontogeny, and sex ratios in the California sea lion. In: Trillmich F, Ono KA (eds) Pinnipeds and El Niño: responses to environmental stress. Springer, Berlin, pp 185–192Google Scholar
  32. Owens M, Owens D (1978) Feeding ecology and its influence on social organisation in brown hyenas (Hyaena brunnea, Thunberg) of the central Kalahari Desert. E Afr Wildl J 16:113–135Google Scholar
  33. Pyke GH, Pulliam HR, Charnov EL (1977) Optimal foraging: a selective review of theory and tests. Q Rev Biol 52:137–154CrossRefGoogle Scholar
  34. Rand RW (1956) The Cape fur seal Arctocephalus pusillus (Schreber). Its general characteristics and moult. Investl Rep Sea Fish Res Inst S Afr 21:1–52Google Scholar
  35. Rand RW (1967) The Cape fur seal (Arctocephalus pusillus). 3. General behaviour on land and at sea. Investl Rep Sea Fish Res Inst S Afr 60:1–39Google Scholar
  36. Shaughnessy PD (1987) Population size of the Cape fur seal Arctocephalus pusillus. 1. From aerial photography. Investl Rep Sea Fish Res Inst S Afr 130:1–56Google Scholar
  37. Short J, Kinnear JE, Robley A (2002) Surplus killing by introduced predators in Australia—evidence for ineffective anti-predator adaptations in native prey species? Biol Conserv 103:283–301CrossRefGoogle Scholar
  38. Sih A (1980) Optimal foraging: partial consumption of prey. Am Nat 116:281–290CrossRefGoogle Scholar
  39. Skinner JD, van Aarde RJ, Goss RA (1995) Space and resource use by brown hyenas (Hyaena brunnea) in the Namib Desert. J Zool 237:123–131CrossRefGoogle Scholar
  40. Temple SA (1987) Do predators always capture substandard individuals disproportionately from prey populations? Ecology 68:669–674CrossRefGoogle Scholar
  41. Trillmich F, Kooyman GL, Majluf P, Sanchez-Grinan M (1986) Attendance and diving behavior of South American fur seals during El Nino in 1983. In: Gentry RL, Kooyman GL (eds) Fur seals: maternal strategies on land and at sea. Princeton University Press, Princeton, pp 153–167Google Scholar
  42. Wiesel I (1998) Beobachtungen Brauner Hyanen an einer Kap-Pelzrobben-Kolonie in der sudlichen Namibwuste, Namibia: Zur Nahrungsokologie und zum Jagdverhalten. Unpublished MSc thesis, University of Hamburg, HamburgGoogle Scholar

Copyright information

© Springer-Verlag and ISPA 2010

Authors and Affiliations

  1. 1.Brown Hyena Research ProjectLüderitzNamibia

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