Producer-scrounger Game Research Articles

Head position as an indicator of producer and scrounger tactics in a ground-feeding bird

The benefits of group foraging depend on the frequency of feeding from food uncovered by companions (joining) versus self-discovered food (finding). Information-sharing (IS) and producer–scrounger (PS) games predict different joining frequencies because they make distinct assumptions about food searching. IS games assume individuals can search concurrently for finding and joining opportunities while PS games assume incompatible search modes; individuals search either as a producer, detecting only finding opportunities, or as a scrounger, detecting only joining opportunities. To determine the search assumption for flocks of ground-feeding granivores we studied the behaviour of spice finches, Lonchura punctulata, foraging in indoor aviaries for clumps of hidden millet seed. We looked for behaviour patterns preceding finding and joining events. An analysis of covariance showed that the frequencies of hopping with the head pointing up and down were statistically associated with the frequencies of a bird's joining and finding, respectively. When the expected stable frequency of the scrounger tactic was altered by changing the seed distribution, the birds' relative frequency of hopping with the head up changed accordingly. When the seed distribution made any use of the scrounger tactic unprofitable, the frequency of hopping with the head up declined to zero. Consequently, in ground-feeding birds such as spice finches, finding and joining behaviour conform more closely to the assumptions of a PS rather than an IS game.

Breeding colonies as information centers: a reappraisal of information-based hypotheses using the producer--scrounger game

One of the most cited hypotheses for the evolutionary advantages of colonial breeding proposes that colonies serve as a place of information exchange about the location of food—the information center hypothesis. Despite its popularity, the hypothesis generated considerable controversy over its predictions and role in the evolution of colonial breeding. As a consequence, the hypothesis still lingers on, despite numerous apparent falsifications from both observational and experimental approaches. The controversy has three roots: the unclear causal direction between coloniality and information center, the unrecognized distinction between colonial breeding and colonial roosting, and the use of an implicit group selectionist argument. Here we try to clarify this controversy by applying an entirely individual selection-based approach, the producer–scrounger game, to the information center hypothesis. Furthermore, we show how other information-based alternatives of the original information center hypothesis (e.g., local enhancement and recruitment center hypotheses) can be included in a common framework. Our model predicts that individuals relying on information transfer at the colony should be rather common in nature. This prediction is essentially unaltered by the inclusion of either local enhancement or recruitment center. On the other hand, the frequency of leading unknowledgeable individuals (the most accepted sign of information center) is expected to be very low. The model indicates that tests of information-based hypotheses should focus on the expected relative frequency of food-searching flights rather than the frequency of leading. Key words: information center, local enhancement, producer–scrounger games, recruitment center. [Behav Ecol 12:121–127 (2001)]

Learning Rules for Social Foragers: Implications for the Producer–Scrounger Game and Ideal Free Distribution Theory

In population games, the optimal behaviour of a forager depends partly on courses of action selected by other individuals in the population. How individuals learn to allocate effort in foraging games involving frequency-dependent payoffs has been little examined. The performance of three different learning rules was investigated in several types of habitats in each of two population games. Learning rules allow individuals to weigh information about the past and the present and to choose among alternative patterns of behaviour. In the producer–scrounger game, foragers use producer to locate food patches and scrounger to exploit the food discoveries of others. In the ideal free distribution game, foragers that experience feeding interference from companions distribute themselves among heterogeneous food patches. In simulations of each population game, the use of different learning rules induced large variation in foraging behaviour, thus providing a tool to assess the relevance of each learning rule in experimental systems. Rare mutants using alternative learning rules often successfully invaded populations of foragers using other rules indicating that some learning rules are not stable when pitted against each other. Learning rules often closely approximated optimal behaviour in each population game suggesting that stimulus–response learning of contingencies created by foraging companions could be sufficient to perform at near-optimal level in two population games.

Experimental evidence that group foragers can converge on predicted producer–scrounger equilibria

When foraging together, animals are often observed to feed from food discoveries of others. The producer–scrounger (PS) game predicts how frequently this phenomenon of food parasitism should occur. The game assumes: (1) at any moment all individuals can unambiguously be categorized as either playing producer (searching for undiscovered food resources) or scrounger (searching for exploitation opportunities), and (2) the payoffs received from the scrounger tactic are negatively frequency dependent; a scrounger does better than a producer when the scrounger tactic is rare, but worse when it is common. No study to date has shown that the payoffs of producer and scrounger conform to the game's assumptions or that groups of foragers reach the predicted stable equilibrium frequency (SEF) of scrounger, whereby both tactics obtain the same payoff. The current study of three captive flocks of spice finches, Lonchura punctulata, provides the first test of the PS game using an apparatus in which both assumptions of the PS game are met. The payoffs to the scrounger, measured as feeding rate (seeds/s), were highly negatively frequency dependent on the frequency of scrounger. The feeding rate for scrounger declined linearly while the rate for producer either declined only slightly or not at all with increasing scrounger frequency. When given the opportunity to alternate between tactics, the birds changed their use of each, such that the group converged on the predicted SEF of scrounger after 5–8 days of testing. Individuals in this study, therefore, demonstrated sufficient plasticity in tactic use such that the flock foraged at the SEF of scrounger.

Daily Patterns of Optimal Producer and Scrounger Use under Predation Hazard: A State-Dependent Dynamic Game Analysis.

Feeding in groups often gives rise to joining: feeding from other's discoveries. The joining decision has been modeled as a producer-scrounger game where the producer strategy consists of searching for one's food and the scrounger strategy consists of searching for food discovered by others. Previous models revealed that the evolutionarily stable proportion of scrounging mostly depends on the fraction of each food patch available only to its producer. These early models are static and state independent and are therefore unable to explore whether the time of day, the animal's state, and the degree of predation hazard influence an individual's decision of whether to use the producer or scrounger strategy. To investigate these issues, we developed a state-dependent dynamic producer-scrounger game model. The model predicts that, early in the day, low reserves promote a preference for the scrounger strategy, while the same condition late in the day favors the use of the producer strategy. Under rich and clumped food, the availability of scrounging can improve the daily survival of any average group member. The model suggests only weak effects of predation hazard on the use of scrounging. Future developments should consider the effects of dominance asymmetries and allowing foragers a choice between foraging alone or in a group harboring an evolutionarily stable frequency of scrounger.

Influence of Conspecific Attraction on the Spatial Distribution of Learning Foragers in a Patchy Habitat

1. Individuals in many social species are attracted to feeding conspecifics. The profitability of conspecific attraction is negatively frequency-dependent and can be modelled as a producer-scrounger (PS) game for which the ESS solution predicts some mixture of producer (no attraction) and scrounger (attraction) tactics in the population. Current models for the spatial distribution of rate-maximizing foragers, which learn the quality of habitats as they exploit patches, ignore the possible effect of conspecific attraction on the stable distribution of foragers. 2, We used simulations of a population with ESS levels of attraction to investigate the effect of conspecific attraction on the spatial distribution of learning foragers which incur travel costs. In habitats where patches depleted slowly, ESS levels of attraction helped foragers which experienced no interference reach the expected ideal free distribution (IFD) by facilitating aggregation to the richest patches. Large aggregations also occurred with interference and thus reduced the fit to the IFD, which in this case predicts a scatter of foragers across patches of varying quality. 3. In habitats where patches depleted rapidly, ESS levels of attraction prevented foragers from reaching the IFD, irrespective of interference levels. Foragers failed to learn habitat quality and thus often aggregated in poor patches, especially in large populations which depleted patches faster and had fewer opportunities to learn quality. 4. Predictions of the model in habitats where patches deplete slowly are supported by several studies. More work is needed for habitats where patches deplete more rapidly. We conclude that conspecific attraction can have important, and often disruptive effects on spatial distributions.

Patch exploitation in a producer-scrounger system: test of a hypothesis using flocks of spice finches (Lonchura punctulata)

Group foraging allows individuals (scroungers) to obtain food discovered by others (producers). Producer-scrounger game models typically overlook the costs and benefits of patch exploitation, assuming instead that producers and scroungers abandon patches simultaneously once depletion occurs. Here we develop an extension of the marginal value theorem of patch exploitation that includes the producer-scrounger dynamics and examine the propensity of a producer to abandon its patch before depletion once scroungers arrive. We predict that early departures should occur more often when expected searching time decreases and when competition intensity in the patch increases. Competition intensity is expected to increase when more scroungers are present or when patches are smaller. We tested these predictions using a within-subject experimental design with six captive flocks of spice finches (Lonchura punctulata), each composed of one producer and three scroungers. As predicted, producers abandoned their food discoveries more frequently once scroungers arrived when searching time was short, when more scroungers were present, and when patches were small. The results show that the producers of a patch often leave as scroungers join their food discoveries because the payoffs from leaving exceed those from staying.

Group Foraging Revisited: Information Sharing or Producer-Scrounger Game?

Previous articleNext article No AccessNotes and CommentsGroup Foraging Revisited: Information Sharing or Producer-Scrounger Game?G. Beauchamp and L.-A. GiraldeauG. Beauchamp Search for more articles by this author and L.-A. Giraldeau Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The American Naturalist Volume 148, Number 4Oct., 1996 Published for The American Society of Naturalists Article DOIhttps://doi.org/10.1086/285951 Views: 17Total views on this site Citations: 25Citations are reported from Crossref Copyright 1996 The University of ChicagoPDF download Crossref reports the following articles citing this article:Johannes Nauta, Pieter Simoens, Yara Khaluf Group size and resource fractality drive multimodal search strategies: A quantitative analysis on group foraging, Physica A: Statistical Mechanics and its Applications 590 (Mar 2022): 126702.https://doi.org/10.1016/j.physa.2021.126702Johannes Nauta, Yara Khaluf, Pieter Simoens Resource ephemerality influences effectiveness of altruistic behavior in collective foraging, Swarm Intelligence 15, no.44 (Nov 2021): 427–457.https://doi.org/10.1007/s11721-021-00205-6Luis Alfaro, Rosalva Cabrera Can the setup of a patch modulate finder’s advantage?, Behavioural Processes 192 (Nov 2021): 104488.https://doi.org/10.1016/j.beproc.2021.104488Uri Hertz, Vaughan Bell, Nichola Raihani Trusting and learning from others: immediate and long-term effects of learning from observation and advice, Proceedings of the Royal Society B: Biological Sciences 288, no.19611961 (Oct 2021).https://doi.org/10.1098/rspb.2021.1414Luis Alfaro, Rosalva Cabrera EFFECT OF GROUP SIZE ON PRODUCER-SCROUNGER STRATEGIES OF WISTAR RATS, Behavioural Processes (Nov 2020): 104280.https://doi.org/10.1016/j.beproc.2020.104280Marie Barou-Dagues, Étienne Richard-Dionne, Frédérique Dubois Do female zebra finches prefer males exhibiting greater plasticity in foraging tactic use?, Behavioral Ecology and Sociobiology 74, no.99 (Aug 2020).https://doi.org/10.1007/s00265-020-02886-1Frédérique Dubois, Étienne Richard‐Dionne Consequences of multiple simultaneous opportunities to exploit others’ efforts on free riding, Ecology and Evolution 10, no.1010 (Apr 2020): 4343–4351.https://doi.org/10.1002/ece3.6201Hannah Page, Andrew Sweeney, Anna Pilko, Noa Pinter-Wollman Underlying mechanisms and ecological context of variation in exploratory behavior of the Argentine ant, Linepithema humile, The Journal of Experimental Biology 221, no.2424 (Nov 2018): jeb188722.https://doi.org/10.1242/jeb.188722Jessica A. Phillips, Stephanie J. Peacock, Andrew Bateman, Mackenzie Bartlett, Mark A. Lewis, Martin Krkošek An asymmetric producer-scrounger game: body size and the social foraging behavior of coho salmon, Theoretical Ecology 11, no.44 (May 2018): 417–431.https://doi.org/10.1007/s12080-018-0375-2David J. White, Hayden B. Davies, Samuel Agyapong, Nora Seegmiller Nest prospecting brown-headed cowbirds ‘parasitize’ social information when the value of personal information is lacking, Proceedings of the Royal Society B: Biological Sciences 284, no.18611861 (Aug 2017): 20171083.https://doi.org/10.1098/rspb.2017.1083Jip J.C. Ramakers, Dina K.N. Dechmann, Rachel A. Page, M. Teague O'Mara Frugivorous bats prefer information from novel social partners, Animal Behaviour 116 (Jun 2016): 83–87.https://doi.org/10.1016/j.anbehav.2016.03.021Alexander E. G. Lee, James P. Ounsley, Tim Coulson, J. Marcus Rowcliffe, Guy Cowlishaw Information use and resource competition: an integrative framework, Proceedings of the Royal Society B: Biological Sciences 283, no.18251825 (Feb 2016): 20152550.https://doi.org/10.1098/rspb.2015.2550Mohammad Afshar, Luc-Alain Giraldeau A unified modelling approach for producer–scrounger games in complex ecological conditions, Animal Behaviour 96 (Oct 2014): 167–176.https://doi.org/10.1016/j.anbehav.2014.07.022Changjun Liu, Yingni Zhai, Lichen Shi, Yixing Gao, Junhu Wei Group area search: A novel nature-inspired optimization algorithm, (Aug 2013): 1352–1357.https://doi.org/10.1109/ICInfA.2013.6720504Sepideh Bazazi, Karin S. Pfennig, Nils Olav Handegard, Iain D. Couzin Vortex formation and foraging in polyphenic spadefoot toad tadpoles, Behavioral Ecology and Sociobiology 66, no.66 (Mar 2012): 879–889.https://doi.org/10.1007/s00265-012-1336-1Etienne Sirot, Philippe Maes, Guillaume Gélinaud Movements and Conflicts in a Flock of Foraging Black-Tailed Godwits (Limosa limosa): The Influence of Feeding Rates on Behavioural Decisions, Ethology 118, no.22 (Dec 2011): 127–134.https://doi.org/10.1111/j.1439-0310.2011.01995.x Shih-Yuan Liu, Karl Hedrick The application of domain of danger in autonomous agent team and its effect on exploration efficiency, (Jun 2011): 4111–4116.https://doi.org/10.1109/ACC.2011.5991366Yasunori Ohtsuka, Yukihiko Toquenaga The patch distributed producer–scrounger game, Journal of Theoretical Biology 260, no.22 (Sep 2009): 261–266.https://doi.org/10.1016/j.jtbi.2009.06.002Andrew J. King, Nick J.B. Isaac, Guy Cowlishaw Ecological, social, and reproductive factors shape producer–scrounger dynamics in baboons, Behavioral Ecology 20, no.55 (Jul 2009): 1039–1049.https://doi.org/10.1093/beheco/arp095Omar Tonsi Eldakar, David Sloan Wilson Selfishness as second-order altruism, Proceedings of the National Academy of Sciences 105, no.1919 (May 2008): 6982–6986.https://doi.org/10.1073/pnas.0712173105Ian M. Hamilton, Lawrence M. Dill GROUP FORAGING BY A KLEPTOPARASITIC FISH: A STRONG INFERENCE TEST OF SOCIAL FORAGING MODELS, Ecology 84, no.1212 (Dec 2003): 3349–3359.https://doi.org/10.1890/02-0227Renee L. Robinette, James C. Ha Social and ecological factors influencing vigilance by northwestern crows, Corvus caurinus, Animal Behaviour 62, no.33 (Sep 2001): 447–452.https://doi.org/10.1006/anbe.2001.1772Bruce Winterhalder, Flora Lu, Bram Tucker Risk-senstive adaptive tactics: Models and evidence from subsistence studies in biology and anthropology, Journal of Archaeological Research 7, no.44 (Dec 1999): 301–348.https://doi.org/10.1007/BF02446047GUY BEAUCHAMP The effect of group size on mean food intake rate in birds, Biological Reviews 73, no.44 (Oct 2008): 449–472.https://doi.org/10.1111/j.1469-185X.1998.tb00179.xMarc Bélisle FORAGING GROUP SIZE: MODELS AND A TEST WITH JAEGERS KLEPTOPARASITIZING TERNS, Ecology 79, no.66 (Sep 1998): 1922–1938.https://doi.org/10.1890/0012-9658(1998)079[1922:FGSMAA]2.0.CO;2

A test of the producer-scrounger foraging game in captive flocks of spice finches, Loncbura punctulata

Group foraging allows the co-existence of a strategy (producer) that involves searching for food, and its alternative (scrounger) exploiting the food of the producer. The use of producer and scrounger strategies has been modelled as an alternative-option scramble which assumes strong negative frequency-dependence of the scrounger's pay-offs. We tested this assumption in a flock feeding situation by manipulating the proportion of scroungers in flocks of spice finches, Lonchura punctulata. In a first experiment we found that: (1) the food intake of scroungers, and to a lesser extent producers, was negatively affected by an increase in the proportion of scroungers; (2) the food intake of producers and scroungers was equal when the proportion of scroungers was small, suggesting that producers, who exploited 35.4% of their patches by scrounging were opportunistically adjusting their use of the strategies until the pay-offs equalized. In a second experiment we tested whether finches could vary their use of the two strategies in response to changes in foraging conditions brought about by an increase in the cost of producing. As predicted by the game, finches reduced their use of the producer strategy and increased their use of the scrounger strategy when the cost of producing increased. These results suggest that spice finches can alter their allocation to each foraging alternative by experience and that the producer-scrounger game is a realistic model for predicting group foraging decisions.