Leopard seals (Hydrurga leptonyx) use suction and filter feeding when hunting small prey underwater

Abstract

Leopard seals (Hydrurga leptonyx) are unusual among apex predators in that they feed at both the top and near the bottom of marine food webs; they capture and consume marine amniotes (seals and penguins) as well as krill. This is thought to be achieved with their unusual dentition: rostral caniniform teeth function to grip large prey and tricuspate postcanines function to sieve krill. The use of canine teeth is known, yet until now, the function of the postcanines has never been documented. Here, we present the first direct observations of filter feeding in leopard seals. Suction was used to draw small prey into the mouth followed by expulsion of ingested seawater through the sieve formed by postcanine teeth. Individuals show abrasive wear on canines and incisors, but not postcanines. This suggests that postcanines are not systematically used for piercing prey during macrophagous feeding, confirming that the postcanines primarily serve a sieving function. Rather than being less efficient at feeding as a result of its polarized diet, the leopard seal is well adapted towards two disparate feeding modes.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

References

  1. Adam PJ, Berta A (2002) Evolution of prey capture strategies and diet in the Pinnipedimorpha (Mammalia, Carnivora). Oryctos 4:83–107

    Google Scholar 

  2. Ainley DG, Ballard G, Karl BJ, Dugger KM (2005) Leopard seal predation rates at penguin colonies of different size. Antarctic Sci 17:335–340. doi:10.1017/s0954102005002750

    Article  Google Scholar 

  3. Bloodworth B, Marshall CD (2005) Feeding kinematics of Kogia and Tursiops (Odontoceti: Cetacea): characterization of suction and ram feeding. J Exp Biol 208:3721–3730. doi:10.1242/jeb.01807

    PubMed  Article  Google Scholar 

  4. Carbone C, Mace GM, Roberts SC, Macdonald DW (1999) Energetic constraints on the diet of terrestrial carnivores. Nature 402:286–288. doi:10.1038/46266

    PubMed  Article  CAS  Google Scholar 

  5. Casaux R, Baroni A, Ramón A, Carlini A, Bertolin M, DiPrinzio CY (2009) Diet of the leopard seal Hydrurga leptonyx at the Danco Coast, Antarctic Peninsula. Polar Biol 32:307–310. doi:10.1007/s00300-008-0567-0

    Article  Google Scholar 

  6. Costa GC (2009) Predator size, prey size, and dietary niche breadth relationships in marine predators. Ecology 90:2014–2019. doi:10.1890/08-1150.1

    PubMed  Article  Google Scholar 

  7. Davis RW, Fuiman LA, Williams TM, Collier SO, Hagey WP, Kanatous SB, Kohin S, Horning M (1999) Hunting behavior of a marine mammal beneath the Antarctic fast ice. Science 283:993–996. doi:10.1126/science.283.5404.993

    PubMed  Article  CAS  Google Scholar 

  8. Edwards EWJ, Forcada J, Crossin GT (2010) First documentation of leopard seal predation of South Georgia pintail duck. Polar Biol 33:403–405. doi:10.1007/s00300-009-0709-z

    Article  Google Scholar 

  9. Fitzgerald EMG (2006) A bizarre new toothed mysticete (Cetacea) from Australia and the early evolution of baleen whales. Proc R Soc B 273:2955–2963. doi:10.1098/rspb.2006.3664

    PubMed  Article  Google Scholar 

  10. Fossette S, Gleiss AC, Casey JP, Lewis AR, Hays GC (2011) Does prey size matter? Novel observations of feeding in the leatherback turtle (Dermochelys coriacea) allow a test of predator—prey size relationships. Biol Letters. doi:10.1098/rsbl.2011.0965

    Google Scholar 

  11. Hall-Aspland SA, Rogers TL (2004) Summer diet of leopard seals (Hydrurga leptonyx) in Prydz Bay, Eastern Antarctica. Polar Biol 27:729–734. doi:10.1007/s00300-004-0662-9

    Article  Google Scholar 

  12. Hamilton JE (1939) The leopard seal Hydrurga leptonyx (De Blainville). Discovery Reports 18:239–264

    Google Scholar 

  13. Heithaus MR, Dill LM (2009) Feeding strategies and tactics. In: Perrin WF, Würsig B, Thewissen JGM (eds) Encyclopedia of marine mammals, 2nd edn. Academic Press, San Diego, pp 414–423

    Google Scholar 

  14. Kane EA, Marshall CD (2009) Comparative feeding kinematics and performance of odontocetes: belugas, Pacific white-sided dolphins and long-finned pilot whales. J Exp Biol 212:3939–3950. doi:10.1242/jeb.034686

    PubMed  Article  CAS  Google Scholar 

  15. Kastelein RA, Mosterd P (1989) The excavation technique for molluscs of Pacific walrusses (Odobenus rosmarus divergens) under controlled conditions. Aquat Mamm 15(1):3–5

    Google Scholar 

  16. Kastelein RA, Gerrits NM, Dubbeldam JL (1991) The anatomy of the walrus head (Odobenus rosmarus): part 2. Description of the muscles and of their role in feeding and haul-out behavior. Aquat Mamm 17:156–180

    Google Scholar 

  17. Klages NTW, Cockcroft VG (1990) Feeding behaviour of a captive crabeater seal. Polar Biol 10:403–404. doi:10.1007/BF00237828

    Google Scholar 

  18. Lowry LF, Testa JW, Calvert W (1988) Notes on winter feeding of crabeater and leopard seals near the Antarctic Peninsula. Polar Biol 8:475–478. doi:10.1007/BF00264724

    Article  Google Scholar 

  19. Marshall CD, Kovacs KM, Lydersen C (2008) Feeding kinematics, suction and hydraulic jetting capabilities in bearded seals (Erignathus barbatus). J Exp Biol 211:699–708. doi:10.1242/jeb.009852

    PubMed  Article  Google Scholar 

  20. Naito Y, Bornemann H, Takahashi A, McIntyre T, Plötz J (2010) Fine-scale feeding behavior of Weddell seals revealed by a mandible accelerometer. Polar Sci 4:309–316

    Article  Google Scholar 

  21. Øritsland T (1977) Food consumption of seals in the Antarctic pack ice. In: Llano GA (ed) Adaptations within antarctic ecosystems, Proceedings of the Third SCAT symposium on Antarctic Biology, Smithsonian Institution, Washington DC, pp 749–768

  22. Rogers TL (2009) Leopard seal Hydrurga leptonyx. In: Perrin WF, Würsig B, Thewissen JGM (eds) Encyclopedia of Marine Mammals, 2nd edn. Academic Press, San Diego, pp 673–674

    Google Scholar 

  23. Ross GJB, Ryan F, Saayman GS, Skinner J (1976) Observations on two captive crabeater seals Lobodon carcinophagus at the Port Elizabeth Oceanarium. Intl Zoo Yearbook 16:160–164

    Article  Google Scholar 

  24. Sanderson SL, Wassersug R (1993) Convergent and alternative designs for vertebrate suspension feeding. In: Hanken J, Hall BK (eds) The Skull, vol 3. University of Chicago Press, Chicago

    Google Scholar 

  25. Siniff DB, Stone S (1985) The role of the leopard seal in the tropho-dynamics of the Antarctic marine ecosystem. In: Siegfried WR, Condy PR, Laws RM (eds) Antarctic nutrient cycles and food webs. Springer, Berlin, pp 555–560

    Google Scholar 

  26. Skinner JP (2009) Head striking during fish capture attempts by Steller sea lions and the potential for using head surge acceleration to predict feeding behaviour. Endangered Species Research 10:61–69. doi:10.3354/esr00236

    Article  Google Scholar 

  27. Stephens DW, Krebs JR (1986) Foraging theory. Princeton University Press, Princeton NJ

    Google Scholar 

  28. Stirling I (1969) Tooth wear as a mortality factor in the Weddell seal, Leptonychotes weddelli. J Mammal 50:559–565

    Article  Google Scholar 

  29. Viviant M, Trites AW, Rosen DAS, Monestiez P, Guinet C (2010) Prey capture attempts can be detected in Steller sea lions and other marine predators using accelerometers. Polar Biol 33:713–719. doi:10.1007/s00300-009-0750-y

    Article  Google Scholar 

  30. Werth AJ (2000a) Feeding in marine mammals. In: Schwenk K (ed) Feeding: form function and evolution in tetrapod vertebrates. Academic Press, San Diego, pp 487–526

    Google Scholar 

  31. Werth AJ (2000b) A kinematic study of suction feeding and associated behaviour in the long-finned pilot whale, Globicephala melas (Traill). Mar Mamm Sci 16:299–314. doi:10.1111/j.1748-7692.2000.tb00926.x

    Article  Google Scholar 

  32. Werth AJ (2006a) Mandibular and dental variation and the evolution of suction feeding in Odontoceti. J Mamm 87:579–588. doi:10.1644/05-MAMM-A-279R1.1

    Article  Google Scholar 

  33. Werth A (2006b) Odontocete suction feeding: experimental analysis of water flow and head shape. J Morphol 267:1415–1428. doi:10.1002/jmor

    PubMed  Article  Google Scholar 

Download references

Acknowledgments

We thank John Bengtson and one anonymous reviewer for critically reading early versions of this manuscript; Taronga Zoo and their marine mammal keepers for allowing access to animals in their care and for assistance with this research; W. Longmore, R. O’Brien and K. Roberts for access to Museum Victoria collections; Ady D’Ettore for the photograph in Fig. 5a; and Colin McHenry for provision of materials. This study was supported by Monash University, Museum Victoria and Taronga Conservation Society Australia. ARE acknowledges the support of the Australian Research Council. EMGF acknowledges the support of the Harold Mitchell Foundation.

Author information

Affiliations

Authors

Corresponding author

Correspondence to David P. Hocking.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Video of underwater feeding in leopard seals during both feeding box experimental trials and during scatter feeds were free-floating fish are thrown into the pool (MP4 13417 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hocking, D.P., Evans, A.R. & Fitzgerald, E.M.G. Leopard seals (Hydrurga leptonyx) use suction and filter feeding when hunting small prey underwater. Polar Biol 36, 211–222 (2013). https://doi.org/10.1007/s00300-012-1253-9

Download citation

Keywords

  • Dentition
  • Foraging behaviour
  • Pinnipedia
  • Suction feeding