Advertisement

Polar Biology

, Volume 30, Issue 10, pp 1275–1283 | Cite as

The population trend of southern elephant seals (Mirounga leonina L.) at Macquarie Island (1952–2004)

  • John van den Hoff
  • Harry Burton
  • Ben Raymond
Original Paper

Abstract

Total numbers of adult female southern elephant seals (cows) breeding at Macquarie Island were determined for 19 of the 52 year period between 1952 and 2004. Totals for 1952–1987 (exc. 1959 and 1985) were estimated from the relationship between censuses of the isthmus study area and concurrent censuses for the whole island. Totals for 1987–2004 were obtained by direct census of the entire island in mid-October. Cow numbers decreased from a maximum of about 40,000 in the 1950s to a minimum of 18,300 in 2000, but then increased slightly to 19,200 in 2004. Nonlinear and post-hoc linear analysis of the count data identified 1999 as the year when the exponential rate of change (r) slowed from −1.4% per annum to near zero. The rate of change was not uniform for each census sub-area counted (1987–2004), suggesting that certain terrestrially based density-dependent mechanisms were influencing the annual distribution of cows.

Keywords

Long-term study Rate of increase GAM Non-linear Antarctica Sub-Antarctic 

Notes

Acknowledgments

This study was carried out with the approval of the Antarctic Animal Care and Ionising Radiation Usage Ethics Committee (Department of the Environment, Commonwealth of Australia) and the Tasmanian Parks and Wildlife Service. We especially thank David Slip for initiating the paper and Clive McMahon for inputs into various earlier versions. We also acknowledge the many members of the 1952 - 2004 ANARE to Macquarie Island who helped in the counting of seals. Angela Bender drew Fig. 1.

References

  1. Barbraud C, Weimerskirch H (2001) Emperor penguins and climate change. Nature 411:183–186PubMedCrossRefGoogle Scholar
  2. Bester MN, Lenglart P-Y (1982) An analysis of the southern elephant seal Mirounga leonina breeding population at Kerguelen. South Afr J Antarct Res 12:11–16Google Scholar
  3. Bester MN, Wilkinson IS (1994) Population ecology of southern elephant seals Mirounga leonina at Marion Island. In: Le Boeuf BJ, Laws RM (eds) Elephant seals; population ecology, behaviour and physiology. University of California Press, CaliforniaGoogle Scholar
  4. Bradshaw CJA, Mcmahon CR, Hindell MA, Bester MN, Pistorius PA (2002) Do southern elephant seals show density dependence in fecundity? Polar Biol 25:650–655Google Scholar
  5. Burton HR, van den Hoff J (2002) Humans and the southern elephant seal Mirounga leonina. Aust Mammal 24:127–139Google Scholar
  6. Carrick R, Csordas SE, Ingham SE, Keith K (1962) Studies on the southern elephant seals Mirounga leonina (L.). III. The annual cycle in relation to age and sex. CSIRO Wildl Res 7:119–160Google Scholar
  7. Campagna C, Lewis M (1992) Growth and distribution of a southern elephant seal colony. Mar Mammal Sci 8:387–396CrossRefGoogle Scholar
  8. Caughley G (1977) Analysis of vertebrate populations. Wiley, LondonGoogle Scholar
  9. Condy PR (1979) Annual cycle of the southern elephant seal Mirounga leonina (Linn.) at Marion Island. South Afr J Zool 14:95–102Google Scholar
  10. Croxall JP, Callaghan T, Cervellati R, Walton DWH (1992) Southern Ocean environmental changes: effects on seabird, seal and whale populations [and discussion]. Philosophical transactions: biological sciences, vol 338, no. 1285, Antarctica and Environmental Change (30 November 1992), pp. 319–328Google Scholar
  11. DeSante DF, Rosenberg DK (1998) What do we need to monitor in order to manage landbirds? In: Marzluff J, Sallabanks R (eds) Avian conservation: research and management. Island Press, Washington, pp. 93–106Google Scholar
  12. Dennis B, Desharnais RA, Cushing JM, Costantino RF (1995) Nonlinear demographic dynamics: mathematical models, statistical methods and biological experiments. Ecol Monogr 65:261–281CrossRefGoogle Scholar
  13. Engelhard GH, van den Hoff J, Broekman M, Baarspul ANJ, Field I, Burton HR, Reijnders PJH (2001) Mass of weaned elephant seal pups in areas of low and high human presence. Polar Biol 24:244–251CrossRefGoogle Scholar
  14. Fewster RM, Buckland ST, Siriwardena GM, Baillie SR, Wilson JD (2000) Analysis of population trends for farmland birds using generalized additive models. Ecology 8:1970–1984CrossRefGoogle Scholar
  15. Gotelli NJ (2001) A primer of ecology, 3rd edn. Sinauer Associates, Inc., SunderlandGoogle Scholar
  16. Hastie TJ, Tibshirani RJ (1990) Generalized additive models. Chapman and Hall, LondonGoogle Scholar
  17. Hindell MA, Burton HR (1987) Past and present status of the southern elephant seal (Mirounga leonina) at Macquarie Island. J Zool Lond 213:365–380CrossRefGoogle Scholar
  18. Laws RM (1956) The elephant seal (Mirounga leonina Linn.) II. General, social and reproductive behaviour. Falkland Isl Depend Surv Sci Rep 13:1–88Google Scholar
  19. Link WA, Sauer JR (1997) Estimation of population trajectories from count data. Biometrics 53:488–497CrossRefGoogle Scholar
  20. McCann. TS (1985) Size, status and demography of southern elephant seal (Mirounga leonina) populations. In: Ling JK, Bryden MM (eds) Studies of sea mammals in south latitudes. Proceedings of a symposium of the 52nd ANZAAS congress. South Australian Museum, Adelaide, pp 1–17Google Scholar
  21. McMahon CR, Hindell MA (2003a) Twinning in southern elephant seals: the implications of resource allocation by mothers. Wildl Res 30:35–39CrossRefGoogle Scholar
  22. McMahon CR, Burton HR, Bester MN (2003b) A demographic comparison of two southern elephant seal populations. J Anim Ecol 72:61–74CrossRefGoogle Scholar
  23. McMahon CR, Bester MN, Burton HR, Hindell MA, Bradshaw CJA (2005a) Population status, trends and a re-examination of the hypotheses explaining the recent declines of the southern elephant seal Mirounga leonina. Mammal Rev 35:82–100CrossRefGoogle Scholar
  24. McMahon CR, Hindell MA, Burton HR, Bester MN (2005b) Comparison of southern elephant seal populations, and observations of a population on a demographic knife-edge. Mar Ecol Progr Ser 288:273–283Google Scholar
  25. McMahon CR, van den Hoff J, Burton HR (2005c) Handling intensity and the short- and long-term survival of elephant seals, addressing and quantifying research effects on wild animals. AMBIO 35:420–423Google Scholar
  26. Pistorius PA, Bester MN, Kirkman SP (1999) Dynamic age-distributions in a declining population of southern elephant seals. Antarct Sci 11:445–450Google Scholar
  27. Pistorius PA, Bester MN, Kirkman SP, Taylor FE (2001) Temporal changes in fecundity and age at sexual maturity of southern elephant seals at Marion Island. Polar Biol 24:343–348CrossRefGoogle Scholar
  28. Pistorius PA, Bester MN, Lewis MN, Taylor FE, Campagna C, Kirkman SP (2004) Adult female survival, population trend and the implications of early primiparity in a capital breeder, the southern elephant seal (Mirounga leonina). J Zool Lond 263:107–119CrossRefGoogle Scholar
  29. Press WH, Flannery BP, Teukolsky SA, Vetterling WT (1988) Numerical recipes: the art of scientific computing. Cambridge University Press, Cambridge, p 818Google Scholar
  30. Rothery P, McCann TS (1987) Estimating pup production of southern elephant seals at South Georgia. In: Harris S (ed) Mammal population studies. Symposium of the Zoological Society of London 58:211–223Google Scholar
  31. Rounsevell DE, Copson GR (1982) Growth rate and recovery of a king penguin, Aptenodytes patagonicus, population after exploitation. Aust Wildl Res 9:519–525CrossRefGoogle Scholar
  32. Slip DJ, Burton HR (1999) Population status and seasonal haulout patterns of the southern elephant seal (Mirounga leonina) at Heard Island. Antarct Sci 11:38–47Google Scholar
  33. Stenseth NC, Mysterud A, Ottersen G Hurrell JW, Cahn K-S, Lima M (2002) Ecological effects of climate fluctuations. Science 297:1292–1296PubMedCrossRefGoogle Scholar
  34. Thomas L (1996) Monitoring long-term population change: why are there so many analysis methods? Ecology 77:49–58CrossRefGoogle Scholar
  35. TSSC. (2001) Mirounga leonina (southern elephant seal). Advise to the minister for the Environment and Heritage from the Threatened Species Scientific Committee (TSSC) on amendments to the list of threatened species under the Environment Protection and Biodiversity Conservation Act 1999. (http://www.ea.gov.au/biodiversity/threatened/species/m-leonina.html)Google Scholar
  36. van Aarde RJ (1980) Fluctuations in the population of southern elephant seals Mirounga leonina at Kergeulen Island. South Afr J Zool 15:99–106Google Scholar
  37. van den Hoff J (2001) Dispersal of southern elephant seals (Mirounga leonina L.) marked at Macquarie Island. Wildl Res 28:413–418CrossRefGoogle Scholar
  38. van den Hoff J, Burton H, Davies R (2003) Diet of male southern elephant seals (Mirounga leonina L.) hauled out at Vincennes Bay, East Antarctica. Polar Biol 26:27–31Google Scholar
  39. Wienecke B, Robertson G (2002) Foraging areas of king penguins from Macquarie Island in relation to a marine protected area. Environ Manage 29:662–672PubMedCrossRefGoogle Scholar
  40. Wilkinson IS, Bester MN (1988) Is onshore human activity a factor in the decline of the southern elephant seal? South Afr J Antarct Res 18:14–18Google Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Australian Antarctic DivisionKingstonAustralia

Personalised recommendations