Rands, S. A., Cowlishaw, G., Pettifor, R. A., Rowcliffe, J. M., & Johnstone, R. A. (2003). Spontaneous emergence of leaders and followers in foraging pairs. Nature, 423(6938), 432–434.
Abstract: Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the 'pace-maker' who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple 'rule of thumb' that requires no detailed knowledge of the state of other individuals.
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Camazine, S., Deneubourg, J. L., Franks, N. R., Sneyd, J., Theraula, G., & Bonabeau, E. (2003). Self-Organization in Biological Systems. Princeton: Princeton University Press.
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Couzin, I. D., & Krause, J. (2003). Self-Organization and Collective Behavior in Vertebrates. In Charles T. Snowdon and Timothy J. Roper J. S. R. Peter J. B. Slater (Ed.), Advances in the Study of Behavior (Vol. 32, pp. 1–75). Academic Press.
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Waeber P.O., & Hemelrijk C.K. (2003). Female Dominance and Social Structure in Alaotran Gentle Lemurs. Behaviour, 140(10), 1235–1246.
Abstract: Abstract:
Lemur social systems have the striking social feature, that adult females consistently evoke submissive behaviour of adult males. In the Alaotran gentle lemur, Hapalemur griseus alaotrensis, however, female dominance has not been studied yet. Here we confirm female dominance over males on the basis of a 5-month field study of the social behaviour of four groups, in the Lake Alaotra marshland of eastern Madagascar. Further, we found that dominant individuals initiated aggressive interactions significantly more often than lowerranking ones, they initiated group movements more often and higher-ranking individuals were groomed more often. The spatial configuration was remarkable, since individuals were closer in space to those more distant in rank.
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Silk, J. B., Alberts, S. C., & Altmann, J. (2003). Social Bonds of Female Baboons Enhance Infant Survival. Science, 302(5648), 1231–1234.
Abstract: Among nonhuman primates, females often form strong bonds with kin and other group members. These relationships are thought to have adaptive value for females, but direct effects of sociality on fitness have never been demonstrated. We present 16 years of behavioral data from a well-studied population of wild baboons, which demonstrate that sociality of adult females is positively associated with infant survival, an important component of variation in female lifetime fitness. The effects of sociality on infant survival are independent of the effects of dominance rank, group membership, and environmental conditions. Our results are consistent with the evidence that social support has beneficial effects on human health and well-being across the life span. For humans and other primates, sociality has adaptive value.
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Aberle, K. S. (2003). Untersuchung der Verwandtschaftsverhältnisse, Inzucht und genetischen Distanzen bei den deutschen Kaltblutpferderassen. Ph.D. thesis, , Hannover.
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van Duijn, M. A. J. (2003). Software for Social Network Analysis. University of Groningen: Heymans Institute/DPMG.
Abstract: This chapter gives a state-of-the art overview of available (free and commercial)
software for social network analysis as of fall 2003. It reviews and compares
six programs, illustrating their functionality with example data. Data manipulation
options and available support are also discussed. Furthermore, seventeen
other, of which nine special-purpose, software packages and ve software routine
packages for general statistical software are reviewed brie
y. The chapter
concludes with some recommendations.
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Kubinyi, E., Topál, J., Miklósi, Á., & Csányi, V. (2003). Dogs (Canis familiaris) learn their owners via observation in a manipulation task. J. Comp. Psychol., 117(2), 156–165.
Abstract: Eighty-seven pet dogs (Canis familiaris) were involved in an experiment in which they had to solve a task to obtain a ball. After witnessing a full demonstration by their owner (10 times pushing the handle of the box, which released a ball), most dogs preferred to touch the handle sooner and more frequently in comparison with other parts of the box, and they used the handle to get the ball. In contrast dogs in 3 control groups developed their own respective methods. The lack of emergence of the ball and playing after the demonstration did not affect the learning performance strongly. This suggests that in dogs the outcome of a demonstration plays only a restricted role in the manifestation of social learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
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Newman, M. E. J. (2003). The Structure and Function of Complex Networks. SIAM Rev., 45(2), 167–256.
Abstract: Inspired by empirical studies of networked systems such as the Internet, social networks, and biological networks, researchers have in recent years developed a variety of techniques and models to help us understand or predict the behavior of these systems. Here we review developments in this field, including such concepts as the small-world effect, degree distributions, clustering, network correlations, random graph models, models of network growth and preferential attachment, and dynamical processes taking place on networks.
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Newman, M. E. J. (2003). Mixing patterns in networks. Phys Rev E Stat Nonlin Soft Matter Phys, 67(2 Pt 2), 026126.
Abstract: We study assortative mixing in networks, the tendency for vertices in networks to be connected to other vertices that are like (or unlike) them in some way. We consider mixing according to discrete characteristics such as language or race in social networks and scalar characteristics such as age. As a special example of the latter we consider mixing according to vertex degree, i.e., according to the number of connections vertices have to other vertices: do gregarious people tend to associate with other gregarious people? We propose a number of measures of assortative mixing appropriate to the various mixing types, and apply them to a variety of real-world networks, showing that assortative mixing is a pervasive phenomenon found in many networks. We also propose several models of assortatively mixed networks, both analytic ones based on generating function methods, and numerical ones based on Monte Carlo graph generation techniques. We use these models to probe the properties of networks as their level of assortativity is varied. In the particular case of mixing by degree, we find strong variation with assortativity in the connectivity of the network and in the resilience of the network to the removal of vertices.
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