The contribution of private and public information in foraging by Australasian gannets
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Predators that forage on foods with temporally and spatially patchy distributions may rely on private or public sources of information to enhance their chances of foraging success. Using GPS tracking, field observations, and videography, we examined potential sites and mechanisms of information acquisition in departures for foraging trips by colonially breeding Australasian gannets (Morus serrator). Analyses of the bill-fencing ceremony between mated pairs of breeding gannets did not detect correlations between parameters of this reciprocal behavior and foraging trips, as would have been predicted if gannets used this behavior as a source of private information. Instead, 60 % of the departing birds flew directly to join water rafts of other conspecific en route to the feeding grounds. The departure of solitary birds from the water rafts was synchronized (within 60 s) with the arrival of incoming foragers and also among departing birds. Furthermore, solitary departing birds from the rafts left in the same directional quadrant (90º slices) as the prior arriving (67 %) and also prior departing forager (79 %). When associated plunge dives of conspecific were visible from the colony, providing a public source of information, gannets more often departed from the water rafts in groups. Our study thus provides evidence for the use of water rafts, but not the nest site, as locations of information transfer, and also confirms the use of local enhancement as a strategy for foraging flights by Australasian gannets.
KeywordsDecision making Information-centre hypothesis Local enhancement Morus serrator Seabirds Water rafts
We acknowledge T. Fettermann, S. Clements, G. Greyling, A. Boyer, L. Meynier, L. van Zonneveld, T. Greenawalt, E. Martínez, K. & S. Machovsky, and S. Ismar for assistance in the field. We also thank the Napier Department of Conservation office for the permission to use the ranger’s house during field work and the Cape Kidnappers’ landowners and farm managers for access to their property. We thank E. Martínez, S. Dwyer and L. Pichegru for helpful comments on early versions of the manuscript and I. Couzin for his assistance during the funding application. This research was funded by National Geographic Waitt Grant and the Massey University Research Fund.
The experiments in the present study were conducted under Massey University Animal Ethics (09/76) and New Zealand Department of Conservation (DoC) permits (ECHB-23237-RES).
Conflict of interest
The authors declare that they have no conflict of interest.
- Batschelet E (1981) Circular statistics in biology. Academic Press, New YorkGoogle Scholar
- Bellier E, Cetain G, Chadoeuf J, Monestiez P, Bretagnolle V (2005) Spatial pattern in seabirds’ distribution: testing for influence of foraging strategies. The case of Northern gannets in the Bay of Biscay. ICES CM 2005/L:13Google Scholar
- Machovsky-Capuska GE (2012) Hunting between the air and the water: the Australasian gannet (Morus serrator). PhD thesis, Massey University, New ZealandGoogle Scholar
- Machovsky-Capuska GE, Hauber ME, Libby E, Wikelski MC, Schuckard R, Melville D, Cook W, Houston M, Raubenheimer D (2013a) Foraging behaviour and habitat use of chick-rearing Australasian gannets in New Zealand. J Ornithol. doi: 10.1007/s10336-013-1018-4
- Machovsky-Capuska GE, Vaughn-Hirshorn RL, Würsig B, Raubenheimer D (2013b) Can gannets define their diving profile prior to submergence? Notornis 60:255–257Google Scholar
- McGillivray J (1842) Account of the Island of St Kilda, chiefly with reference to its natural history. Edinb New Philos J 32:47–70Google Scholar
- Nelson JB (1978) The Sulidae: gannets and boobies. Oxford University Press, OxfordGoogle Scholar
- Nelson JB (2005) Pelicans, cormorants and their relatives. Oxford University Press, OxfordGoogle Scholar
- Pennycuick CJ (1989) Bird flight performance: a practical calculation manual. Oxford University Press, OxfordGoogle Scholar
- Robertson D (1992) Diet of the Australasian gannet Morus serrator (G.R. Gray) around New Zealand. N Z J Ecol 16:77–81Google Scholar
- Schuckard R, Melville D, Cook W, Machovsky-Capuska GE (2012) Diet of the Australasian gannet (Morus serrator) at Farewell Spit, New Zealand. Notornis 59:66–70Google Scholar
- Stephenson B (2005) Variability in the breeding ecology of Australasian gannets (Morus serrator) at Cape Kidnappers, New Zealand. PhD thesis, Massey University, New ZealandGoogle Scholar
- Thorpe WH (1963) Learning and instinct in animals. Methuen, LondonGoogle Scholar
- von Frisch K (1967) The dance language and orientation of bees 28–235. Harvard University Press, HarvardGoogle Scholar
- Wakefield ED, Bodey TW, Bearhop S, Blackburn J, Colhoun K, Davies R, Dwyer RG, Green JA, Grémillet D, Jackson AL, Jessopp MJ, Kane A, Langston RH, Lescroël A, Murray S, Le Nuz M, Patrick SC, Péron C, Soanes LM, Wanless S, Votier SC, Hamer KC (2013) Space partitioning without territoriality in gannets. Science 341:68–70PubMedCrossRefGoogle Scholar
- Zeil J (2008) Orientation, navigation and searching. In: Jorgensen SE, Fath BD (eds) Behavioral ecology (vol 3) of encyclopedia of ecology. Elsevier, OxfordGoogle Scholar