Abstract
There is little information on the effort put into foraging by seabirds, even though it is fundamental to many issues in behavioural ecology. Recent researchers have used changes in the underwater cruising speed of penguins to allude to prey ingestion since accelerations are thought to reflect the encounter and pursuit of prey. In this study, we attached minute accelerometers, to determine flipper beat frequency as a proxy for prey pursuit, to Little Penguins Eudyptula minor foraging in shallow waters in Western Australia. During diving, Little Penguins flapped continuously and at a regular pace of 3.16 Hz while descending the water column and throughout the bottom phase of most dives. However, the frequency and amplitude of wingbeats increased transitorily, reaching 3.5–5.5 Hz, during some dives indicating prey pursuit. Pursuit phases lasted a mean of 2.9±3.3 s and occurred principally during the bottom phases of dives (75.4%). Most dives in all birds (86%) had a clear square-shaped depth profile indicating feeding activity near the seabed in the shallow waters of the bays. Hourly maximum depth, time spent underwater, percentage of dives with pursuit events and catch per unit effort showed an overall increase from zero at ca. 0500 h to a maximum during the hours around mid-day before decreasing to zero by 1900 h. During pursuit phases, Little Penguins headed predominantly downward, probably using the seabed to assist them in trapping their prey. In the light of our results, we discuss depth use by Little Penguins and their allocation of foraging effort and prey capture success as a function of environmental conditions.






Similar content being viewed by others
References
Bannasch R, Wilson RP, Culik BM (1994) Hydrodynamics aspects of design and attachment of a back-mounted device in penguins. J Exp Biol 194:83–96
Bethge P, Nicol S, Culik BM, Wilson RP (1997) Diving behaviour and energetics in breeding little penguins (Eudyptula minor). J Zool Lond 242:483–502
Cannell BL (1994) The feeding behaviour of Little Penguins, Eudyptula minor. PhD Thesis, Monash University, Melbourne
Cannell BL, Cullen J (1998) The foraging behaviour of Little Penguins Eudyptula minor at different light levels. Ibis 140:467–471
Croxall JP, Davis RW, O’Connell MJ (1988) Diving patterns in relation to diet of gentoo and macaroni penguins at South Georgia. Condor 90:157–167
Duffy DC, Todd FS, Siegfried WR (1987) Submarine foraging behavior of alcids in an artificial environment. Zoo Biol 6:373–378
Gales RP (1989) Feeding ecology and free-living energetics of the Little Penguin, Eudyptula minor, in Tasmania. PhD Dissertation, University of Tasmania, Hobart, Australia
Gales RC, Williams C, Ritz D (1990) Foraging behaviour of the little penguin, Eudyptula minor: initial results and assessment of instrument effect. J Zool Lond 220:61–85
Grémillet D (1997) Catch per unit effort, foraging efficiency, and parental investment in breeding great cormorant (Phalacrocorax carbo carbo). ICES J Mar Sci 54:635–644
Jerlov NG (1968) Optical oceanography. Elsevier, Amsterdam, pp 194
Klomp NI, Wooller RD (1988) Diet of Little Penguins, Eudyptula minor, from Penguin Island, Western Australia. Aust J Mar Freshw Res 39:633–639
Kooyman GL, Davis RW (1987) Diving behaviour and performance, with special reference to penguins. In: Croxall JP (ed) Seabirds: feeding biology and role in marine ecosystem. Cambridge University Press, London, pp 63–75
Krebs JR (1978) Optimal foraging: decision rules for predators. In: Krebs JR, Davies NB (eds) Behavioral ecology: an evolutionary approach. Blackwell Press, Oxford
Le Boeuf BJ, Costa DP, Huntley AC, Feldkamp SD (1988) Continuous, deep diving in female northern elephant seals Mirounga angustirostris. Can J Zool 66:446–458
Levins R (1968) Evolution in changing environments. Princeton University Press, Princeton, NJ
Martin GR (1999) Eye structure and foraging in king penguins Aptenodytes patagonicus. Ibis 141:444–450
Montague T (1985) A maximum dive recorder for little penguins. Emu 85:264–267
Naito Y (2004) New steps in bio-logging science. Mem Natl Inst Polar Res Spec Issue 58:50–57
Pütz K, Bost CA (1994) Feeding behaviour of free-ranging king penguins (Aptenodytes patagonicus). Ecology 75:489–497
Pyke GH (1984) Optimal foraging theory: a critical review. Ann Rev Ecol Syst 15:523–575
Robinson SA, Hindell MA (1996) Foraging ecology of gentoo penguins Pygoscelis papua at Macquarie Island during the period of chick care. Ibis 138:722–731
Rodary D, Bonneau W, Maho YL, Bost CA (2000) Benthic diving in male emperor penguins Aptenodytes forsteri foraging in winter. Mar Ecol Prog Ser 207:171–181
Ropert-Coudert Y, Sato K, Kato A, Charrassin J-B, Bost C-A, Le Maho Y, Naito Y (2000) Preliminary investigations of prey pursuit and capture by king penguins at sea. Polar Biosci 13:102–113
Ropert-Coudert Y, Kato A, Baudat J, Bost C-A, Le Maho Y, Naito Y (2001a) Feeding strategies of free-ranging Adélie penguins, Pygoscelis adeliae, analysed by multiple data recording. Polar Biol 24:460–466
Ropert-Coudert Y, Kato A, Baudat J, Bost C-A, Le Maho Y, Naito Y (2001b) Time/depth usage of Adélie penguins; an approach based on dive angles. Polar Biol 24:467–470
Ropert-Coudert Y, Kato A, Naito Y, Cannell B (2003) Individual diving strategies in the Little Penguins. Waterbirds 26:403–408
Ropert-Coudert Y, Wilson RP, Daunt F, Kato A (2004a) Patterns of energy acquisition by a central place forager: benefits of alternating short and long foraging trips. Behav Ecol 15:824–830
Ropert-Coudert Y, Grémillet D, Ryan PG, Kato A, Naito Y, Le Maho Y (2004b) Between air and water: the gannet’s plunge dive. Ibis 146:281–290
Ropert-Coudert Y, Grémillet D, Kato A, Ryan PG, Naito Y, Le Maho Y (2004c) A fine-scale time budget of cape gannets provides insights into their foraging strategies. Anim Behav 67:985–992
Sato K, Naito Y, Kato A, Niizuma Y, Watanuki Y, Charrassin J-B, Bost C-A, Handrich Y, Le Maho Y (2002) Buoyancy and maximal diving depth in penguins: do they control inhaling air volume? J Exp Biol 205:1189–1197
Schoener TW (1971) Theory of feeding strategies. Ann Rev Ecol Syst 2:369–404
Schulz M (1987) Observations of feeding of a Little Penguin Eudyptula minor. Emu 87:186–187
Simeone A, Wilson RP (2003) In depth studies of Magellanic foraging behaviour: can we estimate prey consumption by perturbations in the profile? Mar Biol 143:825–831
Sokal RR, Rohlf FJ (1969) Biometry. WH Freeman Press, San Francisco, USA
Stearns SC (1992) The evolution of life history. Oxford University Press, New York, USA
Tanaka H, Takagi Y, Naito Y (2001) Swimming speeds and buoyancy compensation of migrating adult chum salmon Onchorhynchus keta revealed by speed/depth/acceleration data logger. J Exp Biol 204:3895–3904
Takahashi A, Dunn M, Trathan PN, Sato K, Naito Y, Croxall JP (2003) Foraging strategies of Chinstrap penguins at Signy Island, Antarctica: importance of benthic feeding on Antarctic krill. Mar Ecol Prog Ser 250:279–289
Tremblay Y, Cherel Y (2000) Benthic and pelagic dives: a new foraging behaviour in rockhopper penguins. Mar Ecol Prog Ser 204:257–267
Watanuki Y, Niizuma Y, Gabrielsen GW, Sato K, Naito Y (2003) Stroke and glide of wing-propelled divers: deep diving seabirds adjust surge frequency to buoyancy change with depth. Proc R Soc Lond B 270:483–488
Weimerskirch H, Le Corre M, Ropert-Coudert Y, Kato A, Marsac F (2005) The three dimensional flight of red-footed boobies: adaptations to foraging in a tropical environment. Proc R Soc Lond 272:53–61
Wienecke BC, Wooller RD, Klomp NI (1995) The ecology and management of Little Penguins on Penguin Island, Western Australia. In: Dann P, Norman I, Reilly R (eds) The penguins: ecology and management. Surrey Beatty, Sydney, pp 440–467
Wilson RP (1995) Foraging ecology. In: Perrins C, Bock W, Kikkawa J (eds) Bird families of the world: the penguins spheniscidae. Oxford University Press, Oxford, pp 81–106
Wilson RP, Pütz K, Bost C-A, Culik BM, Bannasch R, Reins T, Adelung D (1993) Diel dive depth in penguins in relation to diel vertical migration of prey: whose dinner by candlelight? Mar Ecol Prog Ser 94:101–104
Wilson RP, Culik BM, Bannasch R, Lage J (1994) Monitoring Antarctic environmental variables using penguins. Mar Ecol Prog Ser 106:199–202
Wilson RP, Pütz K, Peters G, Culik B, Scolaro JA, Charrassin J-B, Ropert-Coudert Y (1997a) Long-term attachment of transmitting and recording devices to penguins and other seabirds. Wildl Soc Bull 25:101–106
Wilson RP, Bost C-A, Pütz K, Charrassin J-B, Culik BM, Adelung D (1997b) Southern Rockhopper penguin Eudyptes chrysocome chrysocome foraging at Possession Island. Polar Biol 17:323–329
Wilson RP, Ropert-Coudert Y, Kato A (2002) Rush and grab strategies in foraging marine endotherms: the case for haste in penguins? Anim Behav 63:85–95
Wilson RP, Culik B, Spairani HJ, Coria NR, Adelung D (1991) Depth utilization by penguins and gentoo penguin dive patterns. J Ornithol 132:47–60
Wilson RP, Culik BM, Peters G, Bannasch R (1996) Diving behaviour of Gentoo penguins, Pygoscelis papua; factors keeping dive profiles in shape. Mar Biol 126:153–162
Yoda K, Sato K, Niizuma Y, Kurita M, Bost C-A, Le Maho Y, Naito Y (1999) Precise monitoring of porpoising behaviour of Adélie penguins determined using acceleration data loggers. J Exp Biol 202:3121–3126
Yoda K, Naito Y, Sato K, Takahashi A, Nishikawa J, Ropert-Coudert Y, Kurita M, Le Maho Y (2001) A new technique for monitoring the behaviour of free-ranging Adélie penguins. J Exp Biol 204:685–694
Acknowledgements
This study was financially supported by the Japanese Society for Promotion of Science and Murdoch University. Field experiments were conducted while Y.R-.C. was visiting Murdoch University, Western Australia. The authors wish to acknowledge M. Mitchell, C. Lamont, M. Banks, T. Goodlich, all the wardens of Penguin Island, the staff from the Penguin experience on Penguin Island for their help in the field and the staff from the Perth Zoo for their help during the calibration experiments. J. Holder at the Department for Planning and Infrastructure and three anonymous referees for their helpful comments. Special thanks to A-M. Kato-Ropert and the Cannell-Lunn family. All research was covered by the appropriate Department of Conservation and Land Management permits.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by T. Ikeda, Hakodate
Rights and permissions
About this article
Cite this article
Ropert-Coudert, Y., Kato, A., Wilson, R.P. et al. Foraging strategies and prey encounter rate of free-ranging Little Penguins. Marine Biology 149, 139–148 (2006). https://doi.org/10.1007/s00227-005-0188-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00227-005-0188-x