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Templeton, J. J. (1998). Learning from others' mistakes: a paradox revisited. Anim. Behav., 55(1), 79–85.
Abstract: Some researchers have reported the paradoxical finding of enhanced social learning when naive observers learn from unskilled rather than skilled demonstrators, particularly in discrimination tasks. In two experiments with starlings,Sturnus vulgaris, I considered whether this enhanced learning is because the observer (1) sees incorrect responses only, (2) sees both correct and incorrect responses or (3) sees an increase in the proportion of correct responses over trials. In experiment 1, individual starlings observed a demonstrator bird perform multiple simultaneous discrimination tasks. In one group, the demonstrator always picked the correct stimulus; in another group, the demonstrator always picked the incorrect stimulus; in a third group, the demonstrator consistently picked the correct stimulus 50% of the time. Those subjects that observed only incorrect choices performed significantly better than the other two groups, but none of the birds achieved the 90% correct performance criterion. Experiment 2 involved a single discrimination task; thus, a fourth group was added to control for individual learning. Again, subjects that observed only incorrect responses learned the discrimination significantly more quickly than the other three groups. Subjects that observed the demonstrator make both correct and incorrect responses were equally likely to select the same (correct) or opposite (incorrect) stimulus when the demonstrator picked the correct stimulus. When the demonstrator picked the incorrect stimulus, however, these subjects were significantly more likely to pick the opposite (correct) stimulus. These findings suggest that when learning a discrimination problem, observing a foraging companion's lack of success is more informative than observing its success.
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Taillon, J., & Cote, S. D. (2007). Social rank and winter forage quality affect aggressiveness in white-tailed deer fawns. Anim. Behav., 74(2), 265–275.
Abstract: Achieving a high social rank may be advantageous for individuals at high population densities, because dominance status may determine the priority of access to limited resources and reduce individual loss of body mass. The establishment of dominance relationships between individuals involves variable levels of aggressiveness that can be influenced by resource availability. The relationship between social rank and aggressiveness and the impacts of resource abundance on aggressiveness are, however, poorly understood, but may be relevant to understand the mechanisms determining dominance relationships between individuals. We experimentally simulated, in seminatural enclosures, a deterioration of winter forage quality induced by a high-density deer population and examined the effects of (1) social dominance and (2) diet quality on aggressiveness, forage intake and body mass loss of white-tailed deer, Odocoileus virginianus, fawns during two winters. Within diet-quality treatments, fawns were consistently organized into linear hierarchies and showed clear dominance relationships. Dominants initiated more interactions and showed higher aggressiveness than subordinates, but subordinates had higher forage intake than dominants throughout winter. Social rank did not influence cumulative body mass loss of fawns. During both winters, fawns fed the control diet maintained their aggressiveness level, whereas fawns fed the poor-quality diet decreased it. Our experimental approach revealed that white-tailed deer responded to a reduction in winter forage quality by modifying their aggressiveness, indicating that ungulates may show plasticity not only in their foraging behaviour in response to decreased resources but also in their social behaviour.
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Syme, G. J., & Syme, L. A. (1975). The concept of spatial leadership in farm animals: An experiment with sheep. Anim. Behav., 23(Part 4), 921–925.
Abstract: The concept of spatial leadership as applied to farm animals is discussed with particular emphasis on methodological problems. Using three experimental procedures forced spatial leadership orders were measured in a group of Romney ewes. Comparisons between orders showed the effects of both the different experimental tasks and the social context on leadership structure. Both these variables were found to affect the orders obtained. The results are interpreted in terms of the utility of the concept of spatial leadership in domestic animals and the necessity for more systematic procedural investigations in this area.
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Stueckle, S., & Zinner, D. (2008). To follow or not to follow: decision making and leadership during the morning departure in chacma baboons. Anim. Behav., 75(6), 1995–2004.
Abstract: To benefit from group living, group members need to keep the group cohesive by coordinating time and direction of travelling. Self-organization and leadership are two means of coordination and two types of decision can be made on the group level: combined and consensus. We studied the initiation process of group movements during the morning departure of a group of chacma baboons, Papio hamadryas ursinus, from its sleeping site in De Hoop Nature Reserve, South Africa. Findings from other female-bonded primate groups led us to hypothesize that females should play a major role in the decision-making process. Approximately 75% of the adults made a start attempt, with 62 of 92 attempts being by males. There was no sex difference in the probability of being successful when initiating an attempt. Lactating females initiated fewer than pregnant or cycling females. Thus, at least for this group of chacma baboons, leadership appeared to be distributed and the decision about the timing of departure and travel direction seemed to be a partially shared consensus decision with adult males contributing more to the decision outcome, with a slightly more prominent role of the dominant male. Our results do not support the [`]leading females' hypothesis. No behavioural patterns that might serve as specialized signals leading to a more successful recruitment of other group members were observed. The departure process appeared to be coordinated merely through individuals setting an example by moving off.
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Strayer, F. F. (1976). Learning and imitation as a function of social status in macaque monkeys (Macaca nemestrina). Anim. Behav., 24(4), 835–848.
Abstract: Learning and imitation were examined in animals selected from two groups of sixteen pigtail monkeys. There were significant differences in performance on a cued-alternation task as a function of both social status within the stable group, and prior exposure to a social model. High status animals responded more frequently, but were less successful in acquiring appropriate response delay. Exposure to the model improved response latencies and acquisition of response delay for all subjects. However, model exposure did not improve alternation performance. Results are discussed in terms of prior social experience of the subjects, general learning strategies, and differential sensitivity to multiple reinforcement contingencies. Findings are related to ethological concepts of imitation, and field reports on primate social learning.
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Stoehr S. (1998). Evolution of mate-choice copying: a dynamic model. Anim. Behav., 55(4), 893–903.
Abstract: Mate-choice copying has recently been demonstrated in several species. Two, not mutually exclusive, explanations for copying have been proposed: it reduces sampling costs and/or error of mate choice. In guppies, Poecilia reticulata, and black grouse, Tetrao tetrix, young females seem most likely to copy. Therefore, copying may teach inexperienced females what attractive males look like. I developed a 2-year dynamic model, to investigate under which conditions a mate-copying strategy might first evolve. An original population of pure choosers was assumed, which was invaded by a mutant female, able to copy during her first mating season, thereby instantly improving her ability to assess male quality. Alternatively, she could either wait and learn by observing males, just as non-copiers may do, but incurring some time costs, or choose, relying on her own abilities. The degree to which copying occurred among these mutant, young, inexperienced females increased with an increasing proportion of old, experienced females in the population, and with decreasing time left until the end of the season. The model demonstrates that mate-choice copying may evolve, when young females are poor at discrimination and need to learn what high-quality males look like. Male quality proved to be unimportant for copying to evolve, as long as there are sufficient differences in quality for mate choice to be meaningful. As with previous models, time constraints are an important assumption for copying to be advantageous over non-copying. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.
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Stephens, D. W., Anderson, J. P., & Benson, K. E. (1997). On the spurious occurrence of Tit for Tat in pairs of predator-approaching fish. Anim. Behav., 53(1), 113–131.
Abstract: An experimental analysis of the movements of predator-approaching fish is presented. The experiments evaluated two competing hypotheses. (1) Predator-approaching fish play the game-theoretical strategy Tit for Tat. Alternatively, (2) the movements of predator-approaching fish superficially resemble Tit for Tat, because fish independently orient to a predator and simultaneously attempt to stay close together. Experimental subjects were mosquito fish,Gambusia affinisapproaching a green sunfish,Lepomis cyanellusTwo experiments were performed. Experiment 1 replicated results of Milinski (1987) and Dugatkin (1991), showing thatGambusiacome closer to a visible predator when a mirror is oriented parallel to their direction of travel. Experiment 2 attempted to separate the effects of common orientation and social cohesion in accounting for the frequency of Tit-for-Tat-like motions in pairs of predator-approachingGambusia. Results of experiment 2 suggest that a simple additive combination of the effects of (1) social cohesion in the absence of a visible predator and (2) orientation to a visible predator in the absence of a visible companion can account for the observed frequency of Tit-for-Tat-like motions for pairs of predator-approachingGambusia. It is concluded that predator approach in shoaling fishes is probably a simple by-product mutualism, rather than cooperation maintained by reciprocity in a Prisoner's Dilemma.
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Stennett, C. R., & Strauss, R. E. (2010). Behavioural lateralization in zebrafish and four related species of minnows (Osteichthyes: Cyprinidae). Anim. Behav., 79(6), 1339–1342.
Abstract: Behavioural lateralization has been observed in many species of fishes during stimulus-specific tasks. However, one area that has been overlooked is the study of naïve side bias in motor behaviour of fishes in the absence of direct visual stimulus. To this end, we examined naïve side biases in motor behaviour in five species of minnows (Osteichthyes: Cyprinidae). Fifteen individuals of each species were subjected to a T-shaped test arena, with 40 randomized replicates per individual. We took advantage of rheotaxis by running a slow current of water through each arm of the test apparatus. Of the 75 individuals tested, 55 showed a rightward turning preference. The overall right-biased behaviour observed in these fishes in the absence of systematic stimulus strongly suggests that a stimulus-free control condition be included in the experimental design whenever plausible for studies of laterality in fishes and presumably in other organisms.
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Smith, L. A., Wells, K. L., Marion, G., Swain, D. L., & Hutchings, M. R. (). Effects of group composition on the grazing behaviour of herbivores. Anim. Behav., In Press, Corrected Proof.
Abstract: Animal behaviour is often a function of the animal's physiological state. Groups of animals will often contain individuals with a range of physiological states and the grazing behaviour of herbivores is affected by their physiological state. This study compared the grazing decisions of animals in groups of single and mixed physiological states. Using a grazing model that simulated individual herbivore behaviour in relation to environmental distributions of forage resource (grass) and parasites (faeces), we tested the hypothesis that an animal's level of parasite exposure via the faecal-oral route is affected by the composition of physiological states in the group. Four physiological states were considered: parasite-naïve, parasitized, lactating and parasite-immune animals. Baseline parasite exposure levels for each state were generated by simulating single-state groups and were compared to simulations of each of the six two-state combinations. In single-state groups parasitized animals had the least and lactating animals had the greatest levels of parasite exposure. When co-grazing with lactating animals, parasitized, immune and naïve animals increased their parasite exposure, relative to single-state groups. When co-grazing with parasitized animals, lactating, immune and naïve animals reduced their parasite exposure, relative to single-state groups. There was no difference in parasite exposure of the immune or naïve animals co-grazing together when compared to the single-state groups. These results highlight the need to recognize the impact of the individual when studying group-living animals.
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Smith, J. M., & Parker, G. A. (1976). The logic of asymmetric contests. Anim. Behav., 24(1), 159–175.
Abstract: A theoretical analysis is made of the evolution of behavioural strategies in contest situations. It is assumed that behaviour will evolve so as to maximize individual fitness. If so, a population will evolve an [`]evolutionarily stable strategy', or ESS, which can be defined as a strategy such that, if all members of a population adopt it, no [`]mutant' strategy can do better. A number of simple models of contest situations are analysed from this point of view. It is concluded that in [`]symmetric' contests the ESS is likely to be a [`]mixed' strategy; that is, either the population will be genetically polymorphic or individuals will be behaviourally variable. Most real contests are probably asymmetric, either in pay-off to the contestants, or in size or weapons, or in some [`]uncorrelated' fashion; i.e. in a fashion which does not substantially bias either the pay-offs or the likely outcome of an escalated contest. An example of an uncorrelated asymmetry is that between the [`]discoverer' of a resource and a [`]late-comer'. It is shown that the ESS in asymmetric contests will usually be to permit the asymmetric cue to settle the contest without escalation. Escalated contests will, however, occur if information to the contestants about the asymmetry is imperfect.
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