Abstract
We assessed experimentally how the quality and quantity of social information affected foraging decisions of starlings (Sturnus vulgaris) at different neighbour distances, and how individuals gained social information as a function of head position. Our experimental set up comprised three bottomless enclosures, each housing one individual placed on a line at different distances. The birds in the extreme enclosures were labelled “senders” and the one in the centre “receiver”. We manipulated the foraging opportunities of senders (enhanced, natural, no-foraging), and recorded the behaviour of the receiver. In the first experiment, receivers responded to the condition of senders. Their searching rate and food intake increased when senders foraged in enhanced conditions, and decreased in no-foraging conditions, in relation to natural conditions. Scanning was oriented more in the direction of conspecifics when senders’ behaviour departed from normal. In the second experiment, responses were “dose dependent”: receivers increased their searching rate and orientated their gaze more towards conspecifics with the number of senders foraging in enhanced food conditions. In no-foraging conditions, receivers decreased their searching and intake rates with the number of senders, but no variation was found in scanning towards conspecifics. Differences in foraging and scanning behaviour between enhanced and no-foraging conditions were much lower when neighbours were separated farther. Overall, information transfer within starling flocks affects individual foraging and scanning behaviour, with receivers monitoring and copying senders’ behaviour mainly when neighbours are close. Information transfer may be related to predation information (responding to the vigilance of conspecifics) and foraging information (responding to the feeding success of conspecifics). Both sources of information, balanced by neighbour distance, may simultaneously affect the behaviour of individuals in natural conditions.
Similar content being viewed by others
References
Bahr DB, Bekoff M (1999) Predicting flock vigilance from simple passerine interactions: modelling with cellular automata. Anim Behav 58:831–839
Beauchamp G (1998) The effect of group size on mean food intake rate in birds. Biol Rev 73:449–472
Beauchamp G (2002) Little evidence for visual monitoring of vigilance in zebra finches. Can J Zool 80:1634–1637
Beauchamp G (2003) Group size effects on vigilance: a search for mechanisms. Behav Process 1216:1–11
Beauchamp G, Livoreil B (1997) The effect of group size on vigilance and feeding rate in spice finches (Lonchura punctulata). Can J Zool 75:1526–1531
Bekoff M (1996) Cognitive ethology, vigilance, information gathering, and representation: who might know what and why? Behav Process 35:225–237
Clark CW, Mangel M (1986) The evolutionary advantages of group foraging. Theor Popul Biol 3:45–75
Coolen I, Giraldeau L-A, Lavoie M (2001) Head position as an indicator of producer and scrounger tactics in a ground-feeding bird. Anim Behav 61:895–903
Cresswell W, Hilton GM, Ruxton GD (2000) Evidence for a rule governing the avoidance of superfluous escape flights. Proc R Soc Lond B 267:733–737
Danchin E, Heg D, Doligez B (2001) Public information and breeding habitat selection. In: Clobert J, Danchin E, Dhondt AA, Nichols JD (eds) Dispersal. Oxford University Press, pp 243–258
Dawkins MS (1995) How do hens view other hens? The use of lateral and binocular visual fields in social recognition. Behaviour 132:591–606
Dawkins MS (2002) What are birds looking at? Head movements and eye use in chickens. Anim Behav 63:991–998
Day RW, Quinn GP (1989) Comparisons of treatments after an analysis of variance. Ecol Monogr 59:433–463
Doligez B, Danchin E, Clobert J (2002) Public information and breeding habitat selection in a wild bird population. Science 297:1168–1170
Drent R, Swierstra P (1977) Goose flocks and food-finding: field experiments with barnacle geese in winter. Wildfowl 28:15–20
Elgar MA, Burren PJ, Posen M (1984) Vigilance and perception of flock size in foraging house sparrows (Passer domesticus L.). Behaviour 90:215–223
Fernández-Juricic E, Siller S, Kacelnik A (2004a) Flock density, social foraging and scanning: an experiment with starlings. Behav Ecol (in press)
Fernández-Juricic E, Erichsen JT, Kacelnik A (2004b) Visual perception and social foraging in birds. Trends Ecol Evol (in press)
Franklin III WE, Lima SL (2001) Laterality in avian vigilance: do sparrows have a favourite eye? Anim Behav 62:879–885
Galef BG Jr, Giraldeau L-A (2001) Social influences on foraging in vertebrates: causal mechanisms and adaptive functions. Anim Behav 61:3–15
Galef BG Jr, White DJ (2000) Evidence of social effects on mate choice in vertebrates. Behav Process 51:167–175
Giraldeau L-A, Caraco T (2000) Social foraging theory. Princeton University Press, Princeton
Giraldeau L-A, Valone TJ, Templeton JJ (2002) Potential disadvantages of using socially acquired information. Phil Trans R Soc Lond B 357:1559–1566
Held S, Mendl M, Devereux C, Byrne RW (2002) Foraging pigs alter their behaviour in response to exploitation. Anim Behav 64:157–166
Inglis IR, Isaacson AJ (1978) The response of dark-bellied brent geese (Branta bernicla bernicla) to models of geese in various postures. Anim Behav 26:953–958
Kennedy M, Gray RD (1994) Agonistic interactions and the distribution of foraging organisms: individual costs and social information. Ethology 96:155–165
Koops MA, Abrahams MV (1999) Assessing the ideal free distribution: do guppies use aggression as public information about patch quality? Ethology 105:737–746
Krause J, Ruxton GD (2002) Living in groups. Oxford University Press, Oxford
Krebs JR, Inman AJ (1992) Learning and foraging: individuals, groups, and populations. Am Nat 40:S63-S84
Land MF (1999) The roles of head movements in the search and capture strategy of a tern. J Comp Physiol A 184:265–272
Lima SL, Zollner PA (1996) Anti-predatory vigilance and the limits of collective detection: visual and spatial separation between foragers. Behav Ecol Sociobiol 38:355–363
Maldonado PE, Maturana H, Varela FJ (1988) Frontal and lateral visual system in birds. Frontal and lateral gaze. Brain Behav Evol 32:57–62
Marchetti C, Drent PJ (2000) Individual differences in the use of social information in foraging by captive great tits. Anim Behav 60:131–140
Martin GR (1986) The eye of a passeriform bird, the European starling (Sturnus vulgaris): eye movement amplitude, visual fields and schematic optics. J Comp Physiol A 159:545–557
Martin GR (1993) Producing the image. In: Zeigler HP, Bischof H-J (eds) Vision, brain and behaviour in birds. MIT Press, Cambridge, Mass., pp 5–24
Metz KJ, Prior KA, Mallory M (1991) Do cattle egrets gain information from conspecifics when foraging? Oecologia 86:57–61
Nordell SE, Valone TJ (1998) Mate choice copying as public information. Ecol Lett 1:74–76
Powell GVN (1974) Experimental analysis of the social value of flocking by starlings (Sturnus vulgaris) in relation to predation and foraging. Anim Behav 22:501–505
Pöysä H (1994) Group foraging, distance to cover and vigilance in the teal, Anas crecca. Anim Behav 48:921–928
Pratt DW (1982) Saccadic eye movements are coordinated with head movements in walking chickens. J Exp Biol 97:217–223
Proctor CJ, Broom M, Ruxton GD (2003) A communication-based spatial model of antipredator vigilance. J Theor Biol 220:123–137
Roberts G (1996) Why individuals vigilance declines as group size increases. Anim Behav 51:1077–1086
Roberts G (1997) How many birds does it take to put a flock to fight? Anim Behav 54:1517–1522
Smith JW, Benkman CW, Coffey K (1999) The use and misuse of public information by foraging red crossbills. Behav Ecol 10:54–62
Smith RD, Ruxton GD, Cresswell W (2001) Patch foraging decisions of wild blackbirds: the role of preharvest public information. Anim Behav 61:1113–1124
Smith R (2002) Together for better or worse: why starlings forage in groups. PhD thesis, University of Oxford, Oxford, UK
Templeton JJ (1998) Learning from others’ mistakes: a paradox revisited. Anim Behav 55:79–85
Templeton JJ, Giraldeau L-A (1995a) Public information cues affect the scrounging decisions of starlings. Anim Behav 49:1617–1626
Templeton JJ, Giraldeau L-A (1995b) Patch assessment in foraging flocks of european starlings—evidence for the use of public information. Behav Ecol 6:65–72
Templeton JJ, Giraldeau L-A (1996) Vicarious sampling: the use of personal and public information by starlings foraging in a simple patchy environment. Behav Ecol Sociobiol 38:105–114
Thompson DBA (1983) Prey assessment by plovers (Charadriidae): net rate of energy intake and vulnerability to kleptoparasites. Anim Behav 31:1226–1236
Valone TJ (1989) Group foraging, public information, and patch estimation. Oikos 56:357–363
Valone TJ (1993) Patch information and estimation—a cost of group foraging. Oikos 68:258–266
Valone TJ, Giraldeau L-A (1993) Patch estimation by group foragers: what information is used? Anim Behav 45:721–728
Valone TJ, Templeton JJ (2002) Public information for the assessment of quality: a widespread social phenomenon. Phil Trans R Soc Lond B 357:1549–1557
Whitehead SC (1994) Foraging behaviour and habitat use in the European starling, Sturnus vulgaris, in an agricultural environment. PhD thesis, University of Oxford, Oxford, UK
Whitehead SC, Wright J, Cotton PA (1995) Winter field use by the European starling Sturnus vulgaris: habitat preferences and the availability of prey. J Avian Biol 26:193–202
Acknowledgements
We thank Thomas Valone, Will Cresswell, Jennifer Templeton, Luc-Alain Giraldeau and an anonymous reviewer for their useful comments. The experiments conducted in this study complied with the British laws on animal experimentation. Partial funding was provided by BBSRC grant S13483 to A.K. E.F-J. was funded by Consejo Nacional de Investigaciones Cientificas y Tecnicas and “la Caixa” Foundation. A.K. was also supported by a Fellowship from the Institute for Advanced Studies in Berlin.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by H. Kokko
Rights and permissions
About this article
Cite this article
Fernández-Juricic, E., Kacelnik, A. Information transfer and gain in flocks: the effects of quality and quantity of social information at different neighbour distances. Behav Ecol Sociobiol 55, 502–511 (2004). https://doi.org/10.1007/s00265-003-0698-9
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00265-003-0698-9