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Stöwe, M. & K., K. (2007). Behavioural phenotypes may determine whether social context facilitates or delays novel object exploration in ravens. International Journal of Ornithology, 148(Suppl 2), 179–184.
Abstract: Individuals consistently differ in behavioural phenotypes. Here we examine the interaction between behavioural phenotype and response to social context during novel object exploration in a neophobic corvid species, the raven (Corvus corax). The presence of conspecifics tends to encourage object exploration and learning but may also delay or even inhibit exploratory behaviour. Factors such as individual differences in response to social context may determine whether the presence of a conspecific facilitates or inhibits approach to novel objects. We confronted eleven six-month-old hand-raised ravens with novel objects, both individually and in dyadic combinations. We defined individuals as “fast” and “slow” explorers on the basis of their approach latency to novel objects when tested individually. The presence of a conspecific delayed the approach of fast birds to novel objects. Slow birds, in contrast, approached the novel objects with lower latencies and spent more time close to them when in dyads with fast siblings than when alone. The individuals" approach behaviour seemed to determine whether social context facilitated or delayed exploratory behaviour. This may contribute to explaining ambiguous results concerning the effects of social context in previous studies.
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McGreevy, P. D., & McLean, A. N. (2007). Roles of learning theory and ethology in equitation. Journal of Veterinary Behavior: Clinical Applications and Research, 2(4), 108–118.
Abstract: By definition, ethology is primarily the scientific study of animal behavior, especially as it occurs in a natural environment; applied ethology being the study of animal behavior in the human domain. The terms equine ethology and ethological training are becoming commonplace in the equestrian domain, yet they seem to be used with a conspicuous lack of clarity and with no mention of learning theory. Most of what we do to train horses runs counter to their innate preferences. This article summarizes the ethological challenges encountered by working horses and considers the merits and limitations of ethological solutions. It also questions the use of terms such as “alpha” and “leader” and examines aspects of learning theory, equine cognition, and ethology as applied to horse training and clinical behavior modification. We propose 7 training principles that optimally account for the horse's ethological and learning abilities and maintain maximal responsivity in the trained horse. These principles can be summarized as: (1) use learning theory appropriately; (2) train easy-to-discriminate signals; (3) train and subsequently elicit responses singularly; (4) train only one response per signal; (5) train all responses to be initiated and subsequently completed within a consistent structure; (6) train persistence of current operantly conditioned responses; and (7) avoid and disassociate flight responses. Adherence to these principles and incorporating them into all horse training methodologies should accelerate training success, reduce behavioral wastage of horses, and improve safety for both humans and horses.
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Tibbetts, E. A., & Dale, J. (2007). Individual recognition: it is good to be different. Trends. Ecol. Evol, 22(10), 529–537.
Abstract: Individual recognition (IR) behavior has been widely studied, uncovering spectacular recognition abilities across a range of taxa and modalities. Most studies of IR focus on the recognizer (receiver). These studies typically explore whether a species is capable of IR, the cues that are used for recognition and the specializations that receivers use to facilitate recognition. However, relatively little research has explored the other half of the communication equation: the individual being recognized (signaler). Provided there is a benefit to being accurately identified, signalers are expected to actively broadcast their identity with distinctive cues. Considering the prevalence of IR, there are probably widespread benefits associated with distinctiveness. As a result, selection for traits that reveal individual identity might represent an important and underappreciated selective force contributing to the evolution and maintenance of genetic polymorphisms.
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Holekamp, K. E., Sakai, S. T., & Lundrigan, B. L. (2007). Social intelligence in the spotted hyena (Crocuta crocuta). Philos Trans R Soc Lond B Biol Sci, 362(1480), 523–538.
Abstract: If the large brains and great intelligence characteristic of primates were favoured by selection pressures associated with life in complex societies, then cognitive abilities and nervous systems with primate-like attributes should have evolved convergently in non-primate mammals living in large, elaborate societies in which social dexterity enhances individual fitness. The societies of spotted hyenas are remarkably like those of cercopithecine primates with respect to size, structure and patterns of competition and cooperation. These similarities set an ideal stage for comparative analysis of social intelligence and nervous system organization. As in cercopithecine primates, spotted hyenas use multiple sensory modalities to recognize their kin and other conspecifics as individuals, they recognize third-party kin and rank relationships among their clan mates, and they use this knowledge adaptively during social decision making. However, hyenas appear to rely more intensively than primates on social facilitation and simple rules of thumb in social decision making. No evidence to date suggests that hyenas are capable of true imitation. Finally, it appears that the gross anatomy of the brain in spotted hyenas might resemble that in primates with respect to expansion of frontal cortex, presumed to be involved in the mediation of social behaviour.
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Scordato, E. S., & Drea, C. M. (2007). Scents and sensibility: information content of olfactory signals in the ringtailed lemur, Lemur catta. Anim. Behav., 73(2), 301–314.
Abstract: The function of olfactory signalling in social species is less well understood than in asocial species. Consequently, we examined olfactory communication in the ringtailed lemur, a socially complex primate that retains a functional vomeronasal organ, has well-developed scent glands and shows a suite of scent-marking behaviour. To assess the information content of different types of scent gland secretions, we decoupled olfactory cues from the visual and behavioural modalities with which scent marking is normally associated. We presented male and female subjects (signal receivers) with a series of choice tests between odours derived from conspecific donors (signal senders) varying by sex, age, social status and reproductive condition. We additionally examined the influence of the receivers' reproductive state and familiarity with the signaller. The reproductive condition, social status and familiarity of senders and receivers affected signal transmission; specifically, male receivers attended most to the odours of conspecifics in breeding condition and to the odours of familiar, dominant animals. By contrast, females varied their responses according to both their own reproductive state and that of the sender. Based on male and female patterns of countermarking, we suggest that scent marking serves a function in intergroup spacing and intrasexual competition for both sexes, as might be expected in a female-dominant species. By contrast, minimal female interest in male odours counters a female mate choice function for scent marking in this species. Nevertheless, scent marks are critical to male-male competition and, therefore, may be subject to sexual selection.
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Dreier, S., van Zweden, J. S., & D'Ettorre, P. (2007). Long-term memory of individual identity in ant queens. Biol Lett, 3(5), 459–462.
Abstract: Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant, Pachycondyla villosa, uses chemical cues. In both species, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, we investigated individual recognition in Pachycondyla ants by quantifying the level of aggression between pairs of familiar or unfamiliar queens over time. We show that unrelated founding queens of P. villosa and Pachycondyla inversa store information on the individual identity of other queens and can retrieve it from memory after 24h of separation. Thus, we have documented for the first time that long-term memory of individual identity is present and functional in ants. This novel finding represents an advance in our understanding of the mechanism determining the evolution of cooperation among unrelated individuals.
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Anderson, W. D., & Summers, C. H. (2007). Neuroendocrine Mechanisms, Stress Coping Strategies, and Social Dominance: Comparative Lessons about Leadership Potential. Ann Am Acad Polit Soc Sci, 614(1), 102–130.
Abstract: The authors examine dominance and subordination in the social psychology, political science, and biology literatures. Using Summers and Winberg (2006) as a guide, the authors suggest that extreme dominance or subordination phenotypes--including social dominance orientation and right-wing authoritarianism--are determined by an organism's genetic predispositions, motivations, stress responses, and long-term hormone release and uptake states. The authors offer hypotheses about the likely neurochemical profiles for each of these extreme dominance and subordination phenotypes and suggest two designs that begin to test these hypotheses.
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Peterson, R. O. (2007). The Wolves of Isle Royale: A Broken Balance. Michigan: The university of Michigan Press.
Abstract: About the Book
“Few can rival what Rolf Peterson has accomplished on Isle Royale. His study, a true classic, offers lessons and examples to us all who hope to do the same. This book reveals some of the secrets and details of this one-of-a-kind wolf study.” -Douglas W. Smith, Leader, Yellowstone Wolf Project For nearly half a century Isle Royale National Park has been the site of a comprehensive study on wolves (2008 marks the fiftieth anniversary)-the world's longest-running study on any wild animal. With its lush northern landscape and wolf and moose populations, the pristine and isolated park presents an ideal laboratory for wildlife biologists. The Wolves of Isle Royale is author and wildlife biologist Rolf Peterson's fascinating firsthand account of the relationship that exists between the wolf and the moose on the island. Illustrated with over 100 photographs, this book reveals the true nature of the mysterious and little-understood wolf, and it offers novel solutions to the conservation crisis as the wolf population falters to its lowest recorded level. Rolf O. Peterson is known worldwide for his wolf research. His photographs have been published in National Geographic, Audubon, and National Wildlife. He is Professor of Wildlife Ecology at Michigan Technological University. Cover photo credit: Rolf O. Peterson |
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Pérez-Barbería, F. J., Shultz, S., Dunbar, R. I. M., & Janis, C. (2007). Evidence For Coevolution Of Sociality And Relative Brain Size In Three Orders Of Mammals. Evolution, 61(12), 2811–2821.
Abstract: Abstract
As the brain is responsible for managing an individual's behavioral response to its environment, we should expect that large relative brain size is an evolutionary response to cognitively challenging behaviors. The “social brain hypothesis” argues that maintaining group cohesion is cognitively demanding as individuals living in groups need to be able to resolve conflicts that impact on their ability to meet resource requirements. If sociality does impose cognitive demands, we expect changes in relative brain size and sociality to be coupled over evolutionary time. In this study, we analyze data on sociality and relative brain size for 206 species of ungulates, carnivores, and primates and provide, for the first time, evidence that changes in sociality and relative brain size are closely correlated over evolutionary time for all three mammalian orders. This suggests a process of coevolution and provides support for the social brain theory. However, differences between taxonomic orders in the stability of the transition between small-brained/nonsocial and large-brained/social imply that, although sociality is cognitively demanding, sociality and relative brain size can become decoupled in some cases. Carnivores seem to have been especially prone to this. |
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Gabris, G. T., & Ihrke, D. M. (2007). No End to Hierarchy: Does Rank Make a Difference in Perceptions of Leadership Credibility? Admin. Soc., 39(1), 107–123.
Abstract: This article investigates whether authority hierarchy still serves as an important factor influencing employee perceptions toward organizational roles and expected behavior. Results of a study in a federal agency suggest that hierarchy does serve as a significant force influencing employee attitudes toward leadership roles, contrary to the notion that hierarchy will diminish in importance over time. Hierarchy remains a crucial structural force in public organizations and is unlikely to wither away.
Keywords: hierarchy; leadership; credibility; culture; bureaucracy
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