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001-es BibID:	BIBFORM023418
Első szerző:	Barta Zoltán (biológus, zoológus)
Cím:	Geometry for a selfish foraging group : a genetic algorithm approach / Zoltán Barta, Robyn Flynn, Luc-Alain Giraldeau
Dátum:	1997
Megjegyzések:	Department of Biology, Concordia University, Montreal, Qc, Canada The advantages of group living are not shared equally among all group members, and these advantages may depend on the spatial position occupied by a forager within the group. For instance, it is thought that socially dominant individuals prefer the predator-safe central position of groups forcing subordinates to the periphery. Uneven spread of benefits among group members can occur when some animals (the scroungers) parasitically exploit the food findings of other foragers (the producers). Here we focus on how playing producer or scrounger affects an individual's spatial position within a group. We model the movement of foraging animals playing scrounger or producer using a spatially explicit simulation, and use a genetic algorithm to establish movement rules. We find that groups containing producers and scroungers are more compact compared to an equivalent group of producers only. Furthermore, the position occupied by strategies varies: scroungers are mainly found in central positions, with producers in the periphery, suggesting that the best position for strategies differs. Dominants, therefore, should prefer movement rules which lead to central positions because of the positional benefits provided to the scrounger strategy they use. Moreover, position within a group will introduce an asymmetry among otherwise phenotypically symmetric individuals.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Proceedings of the Royal Society. Series B. Biological sciences. - 264 (1997), p. 1233-1238. -
További szerzők:	Flynn, Robyn Giraldeau, Luc-Alain
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM023238
Első szerző:	Barta Zoltán (biológus, zoológus)
Cím:	Breedingcolonies as information centres : A re-appraisal of information-based hypotheses using the producer-scrounger game / Zoltán Barta, Luc-Alain Giraldeau
Dátum:	2001
ISSN:	1045-2249
Megjegyzések:	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 nzmerous apparent falsifications from both observational and experimental approaches. The controversy has three roots: the unclear casual 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 ertirely individual selection-based approach, the producer-scrounger game, to the information center hypothesis. Futhermore, 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 fligts rather than the frequency of leading.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban Information center local enhancement producer-scrounger games recruitment center
Megjelenés:	Behavioral Ecology. - 12 : 2 (2001), p. 121-127. -
További szerzők:	Giraldeau, Luc-Alain
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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001-es BibID:	BIBFORM023392
Első szerző:	Barta Zoltán (biológus, zoológus)
Cím:	The effect of dominance hierarchy on the use of alternative foraging tactics: a phenotype-limited producing-scrounging game / Zoltán Barta, Luc-Alain Giraldeau
Dátum:	1998
Megjegyzések:	Group living is thought to be advantageous for animals, though it also creates opportunities for exploitation. Using food discovered by others can be described as a producer-scrounger, frequency-dependent game. In the game, scroungers (parasitic individuals) do better than producers (food finders) when scroungers are rare in the group, but they do worse when scroungers are common. When the individuals' payoffs do not depend on their phenotype (i.e. a symmetric game), this strong negative frequency dependence leads to a mixed stable solution where both alternatives obtain equal payoffs. Here, we address the question of how differences in so- cial status in a dominance hierarchy in?uence the indi- viduals' decision to play producer or scrounger in small foraging groups. We model explicitly the food intake rate of each individual in a dominance-structured for- aging group, then calculate the Nash equilibrium for them. Our model predicts that only strong differences in competitive ability will in?uence the use of producing or scrounging tactics in small foraging groups; dominants will mainly play scrounger and subordinates will mostly use producer. Since the differences in competitive ability of different-ranking individuals likely depend on the economic defendability of food, our model provides a step towards the integration of social foraging and re- source defence theories.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban Dominance hierarchy Game theory Group foraging Phenotype limitation Producer-scrounger
Megjelenés:	Behavioral Ecology and Sociobiology. - 42 : 3 (1998), p. 217-223. -
További szerzők:	Giraldeau, Luc-Alain
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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