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Author Neuringer, A.
Title Reinforced variability in animals and people: implications for adaptive action Type Journal Article
Year 2004 Publication (down) The American Psychologist Abbreviated Journal Am Psychol
Volume 59 Issue 9 Pages 891-906
Keywords Animals; Behavior, Animal; *Choice Behavior; Conditioning, Operant; Creativeness; Discrimination (Psychology); Humans; Memory; Problem Solving; *Reinforcement (Psychology)
Abstract Although reinforcement often leads to repetitive, even stereotyped responding, that is not a necessary outcome. When it depends on variations, reinforcement results in responding that is diverse, novel, indeed unpredictable, with distributions sometimes approaching those of a random process. This article reviews evidence for the powerful and precise control by reinforcement over behavioral variability, evidence obtained from human and animal-model studies, and implications of such control. For example, reinforcement of variability facilitates learning of complex new responses, aids problem solving, and may contribute to creativity. Depression and autism are characterized by abnormally repetitive behaviors, but individuals afflicted with such psychopathologies can learn to vary their behaviors when reinforced for so doing. And reinforced variability may help to solve a basic puzzle concerning the nature of voluntary action.
Address Department of Psychology, Reed College, Portland, OR 97202, USA. allen.neuringer@reed.edu
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-066X ISBN Medium
Area Expedition Conference
Notes PMID:15584823 Approved no
Call Number Equine Behaviour @ team @ Serial 4106
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Author Flack, J.C.; de Waal, F.B.M.; Krakauer, D.C.
Title Social structure, robustness, and policing cost in a cognitively sophisticated species Type Journal Article
Year 2005 Publication (down) The American Naturalist Abbreviated Journal Am Nat
Volume 165 Issue 5 Pages E126-139
Keywords Animals; *Behavior, Animal; Cognition; Conflict (Psychology); Female; Macaca nemestrina/*physiology; Male; Models, Biological; *Social Behavior
Abstract Conflict management is one of the primary requirements for social complexity. Of the many forms of conflict management, one of the rarest and most interesting is third-party policing, or intervening impartially to control conflict. Third-party policing should be hard to evolve because policers personally pay a cost for intervening, while the benefits are diffused over the whole group. In this study we investigate the incidence and costs of policing in a primate society. We report quantitative evidence of non-kin policing in the nonhuman primate, the pigtailed macaque. We find that policing is effective at reducing the intensity of or terminating conflict when performed by the most powerful individuals. We define a measure, social power consensus, that predicts effective low-cost interventions by powerful individuals and ineffective, relatively costly interventions by low-power individuals. Finally, we develop a simple probabilistic model to explore whether the degree to which policing can effectively reduce the societal cost of conflict is dependent on variance in the distribution of power. Our data and simple model suggest that third-party policing effectiveness and cost are dependent on power structure and might emerge only in societies with high variance in power.
Address Santa Fe Institute, Santa Fe, New Mexico 87501, USA. jflack@santafe.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1537-5323 ISBN Medium
Area Expedition Conference
Notes PMID:15795848 Approved no
Call Number refbase @ user @ Serial 168
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Author Cameron, E.Z.; du Toit, J.T.
Title Winning by a neck: tall giraffes avoid competing with shorter browsers Type Journal Article
Year 2007 Publication (down) The American naturalist Abbreviated Journal Am Nat
Volume 169 Issue 1 Pages 130-135
Keywords Acacia/growth & development; Animals; Feeding Behavior/*physiology; Neck/*anatomy & histology; Plant Leaves/growth & development; Ruminants/*anatomy & histology/*physiology; South Africa
Abstract With their vertically elongated body form, giraffes generally feed above the level of other browsers within the savanna browsing guild, despite having access to foliage at lower levels. They ingest more leaf mass per bite when foraging high in the tree, perhaps because smaller, more selective browsers deplete shoots at lower levels or because trees differentially allocate resources to promote shoot growth in the upper canopy. We erected exclosures around individual Acacia nigrescens trees in the greater Kruger ecosystem, South Africa. After a complete growing season, we found no differences in leaf biomass per shoot across height zones in excluded trees but significant differences in control trees. We conclude that giraffes preferentially browse at high levels in the canopy to avoid competition with smaller browsers. Our findings are analogous with those from studies of grazing guilds and demonstrate that resource partitioning can be driven by competition when smaller foragers displace larger foragers from shared resources. This provides the first experimental support for the classic evolutionary hypothesis that vertical elongation of the giraffe body is an outcome of competition within the browsing ungulate guild.
Address Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1537-5323 ISBN Medium
Area Expedition Conference
Notes PMID:17206591 Approved no
Call Number refbase @ user @ Serial 410
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Author Uehara, T.; Yokomizo, H.; Iwasa, Y.
Title Mate-choice copying as Bayesian decision making Type Journal Article
Year 2005 Publication (down) The American naturalist Abbreviated Journal Am Nat
Volume 165 Issue 3 Pages 403-410
Keywords Animals; *Bayes Theorem; *Choice Behavior; Female; Male; *Models, Biological; *Sexual Behavior, Animal
Abstract Mate-choice copying by females has been reported in fishes (e.g., guppies) and lekking birds. Presumably, females assess males' quality using both information from direct observation of males and information acquired by observing other females' choices. Here, we study mathematically the conditions under which mate-choice copying is advantageous on the basis of Bayesian decision theory. A female may observe the mate choice of another female, called the model female, who has performed an optimal choice based on her own judgment. The conditions required for the focal female to choose the same mate as that chosen by the model female should depend on the male's appearance to her, the reliability of her own judgment of male quality, and the reliability of the model females. When three or more females are involved, the optimal mate choice critically depends on whether multiple model females make decisions independently or they themselves copy the choices of others. If two equally reliable females choose different males, the choice of the second female, made knowing the choice of the first, should have a stronger effect on the choice of the third (focal) female. This “last-choice precedence” should be tested experimentally.
Address Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan. uehara@bio-math.biology.kyushu-u.ac.jp
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1537-5323 ISBN Medium
Area Expedition Conference
Notes PMID:15729669 Approved no
Call Number Serial 1821
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Author Dubois, F.; Giraldeau, L.-A.; Hamilton, I.M.; Grant, J.W.A.; Lefebvre, L.
Title Distraction sneakers decrease the expected level of aggression within groups: a game-theoretic model Type Journal Article
Year 2004 Publication (down) The American Naturalist Abbreviated Journal Am Nat
Volume 164 Issue 2 Pages E32-45
Keywords *Aggression; Animals; Behavior, Animal/*physiology; Columbidae/*physiology; Competitive Behavior; Cooperative Behavior; *Game Theory; Hawks/*physiology; Models, Biological
Abstract Hawk-dove games have been extensively used to predict the conditions under which group-living animals should defend their resources against potential usurpers. Typically, game-theoretic models on aggression consider that resource defense may entail energetic and injury costs. However, intruders may also take advantage of owners who are busy fighting to sneak access to unguarded resources, imposing thereby an additional cost on the use of the escalated hawk strategy. In this article we modify the two-strategy hawk-dove game into a three-strategy hawk-dove-sneaker game that incorporates a distraction-sneaking tactic, allowing us to explore its consequences on the expected level of aggression within groups. Our model predicts a lower proportion of hawks and hence lower frequencies of aggressive interactions within groups than do previous two-strategy hawk-dove games. The extent to which distraction sneakers decrease the frequency of aggression within groups, however, depends on whether they search only for opportunities to join resources uncovered by other group members or for both unchallenged resources and opportunities to usurp.
Address Departement des Sciences Biologiques, Universite du Quebec a Montreal, Case postale 8888 Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. frede_dubois@yahoo.fr
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1537-5323 ISBN Medium
Area Expedition Conference
Notes PMID:15278850 Approved no
Call Number Serial 2130
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Author Dubois, F.; Giraldeau, L.-A.
Title The forager's dilemma: food sharing and food defense as risk-sensitive foraging options Type Journal Article
Year 2003 Publication (down) The American Naturalist Abbreviated Journal Am Nat
Volume 162 Issue 6 Pages 768-779
Keywords Animals; Competitive Behavior/*physiology; *Environment; Feeding Behavior/*physiology; *Game Theory; *Models, Biological; Population Density; Population Dynamics
Abstract Although many variants of the hawk-dove game predict the frequency at which group foraging animals should compete aggressively, none of them can explain why a large number of group foraging animals share food clumps without any overt aggression. One reason for this shortcoming is that hawk-dove games typically consider only a single contest, while most group foraging situations involve opponents that interact repeatedly over discovered food clumps. The present iterated hawk-dove game predicts that in situations that are analogous to a prisoner's dilemma, animals should share the resources without aggression, provided that the number of simultaneously available food clumps is sufficiently large and the number of competitors is relatively small. However, given that the expected gain of an aggressive animal is more variable than the gain expected by nonaggressive individuals, the predicted effect of the number of food items in a clump-clump richness-depends on whether only the mean or both the mean and variability associated with payoffs are considered. More precisely, the deterministic game predicts that aggression should increase with clump richness, whereas the stochastic risk-sensitive game predicts that the frequency of encounters resulting in aggression should peak at intermediate clump richnesses or decrease with increasing clump richness if animals show sensitivity to the variance or coefficient of variation, respectively.
Address Departement des Sciences Biologiques, Universite du Quebec a Montreal, Case postale 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8, Canada. fdubois@u-bourgogne.fr
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-0147 ISBN Medium
Area Expedition Conference
Notes PMID:14737714 Approved no
Call Number Serial 2132
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Author Conradt, L.; Krause, J.; Couzin, I. D.; Roper, T. J.
Title “Leading According to Need” in Self-Organizing Groups Type Journal Article
Year 2009 Publication (down) The American Naturalist Abbreviated Journal Am Nat
Volume 173 Issue 3 Pages 304-312
Keywords behavioral synchrony, collective group decisions, democracy and egalitarianism in animals, public goods experiments, sexual segregation, social choice theory
Abstract Self‐organizing‐system approaches have shed significant light on the mechanisms underlying synchronized movements by large groups of animals, such as shoals of fish, flocks of birds, or herds of ungulates. However, these approaches rarely consider conflicts of interest between group members, although there is reason to suppose that such conflicts are commonplace. Here, we demonstrate that, where conflicts exist, individual members of self‐organizing groups can, in principle, increase their influence on group movement destination by strategically changing simple behavioral parameters (namely, movement speed, assertiveness, and social attraction range). However, they do so at the expense of an increased risk of group fragmentation and a decrease in movement efficiency. We argue that the resulting trade‐offs faced by each group member render it likely that group movements are led by those members for which reaching a particular destination is most crucial or group cohesion is least important. We term this phenomenon leading according to “need” or “social indifference,” respectively. Both kinds of leading can occur in the absence of knowledge of or communication about the needs of other group members and without the assumption of altruistic cooperation. We discuss our findings in the light of observations on fish and other vertebrates.
Address
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Notes Approved no
Call Number Equine Behaviour @ team @ Serial 5121
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Author Fulhorst, C.F.; Hardy, J.L.; Eldridge, B.F.; Chiles, R.E.; Reeves, W.C.
Title Ecology of Jamestown Canyon virus (Bunyaviridae: California serogroup) in coastal California Type Journal Article
Year 1996 Publication (down) The American Journal of Tropical Medicine and Hygiene Abbreviated Journal Am J Trop Med Hyg
Volume 55 Issue 2 Pages 185-189
Keywords Aedes/virology; Animals; Antibodies, Viral/blood; California/epidemiology; Cattle; Cattle Diseases/epidemiology; Deer; Dog Diseases/epidemiology; Dogs; Encephalitis Virus, California/immunology/*isolation & purification; Encephalitis, California/epidemiology/*veterinary; Female; Horse Diseases/epidemiology; Horses; Insect Vectors/virology; Lagomorpha; Male; Neutralization Tests/veterinary; Peromyscus; Rodent Diseases/epidemiology; Sigmodontinae
Abstract This paper reports the first isolation of Jamestown Canyon (JC) virus from coastal California and the results of tests for antibody to JC virus in mammals living in coastal California. The virus isolation was made from a pool of 50 Aedes dorsalis females collected as adults from Morro Bay, San Luis Obispo County, California. The virus isolate was identified by two-way plaque reduction-serum dilution neutralization tests done in Vero cell cultures. Sera from the mammals were tested for antibody to JC virus by a plaque-reduction serum dilution neutralization method. A high prevalence of JC virus-specific antibody was found in horses and cattle sampled from Morro Bay. This finding is additional evidence for the presence of a virus antigenically identical or closely related to JC virus in Morro Bay and indicates that the vectors of the virus in Morro Bay feed on large mammals. A high prevalence of virus-specific antibody was also found in horses sampled from Marin and San Diego counties. This finding suggests that viruses antigenically identical or closely related to JC virus are geographically widespread in coastal California.
Address School of Public Health, University of California, Berkeley, USA
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9637 ISBN Medium
Area Expedition Conference
Notes PMID:8780458 Approved no
Call Number Equine Behaviour @ team @ Serial 2656
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Author McHugh, C.P.
Title Ecology of a semi-isolated population of adult Anopheles freeborni: abundance, trophic status, parity, survivorship, gonotrophic cycle length, and host selection Type Journal Article
Year 1989 Publication (down) The American Journal of Tropical Medicine and Hygiene Abbreviated Journal Am J Trop Med Hyg
Volume 41 Issue 2 Pages 169-176
Keywords Aging/physiology; Animals; Anopheles/*physiology; Breeding; California; Cattle/parasitology; Dogs/parasitology; Ecology; Feeding Behavior/physiology; Female; Horses/parasitology; Host-Parasite Relations; Male; Parity; Population Density; Rabbits/parasitology
Abstract A population of adult Anopheles freeborni near Sheridan, CA was sampled daily during 13 August-7 September 1984. Data on abundance, trophic status, and gonotrophic age were recorded. Abundance and gonotrophic age data were analyzed to estimate daily survivorship and gonotrophic cycle length. Daily survivorship for unfed mosquitoes was estimated to be 0.72 with a gonotrophic cycle of 6 days duration. Daily survivorship for bloodfed mosquitoes was estimated to be 0.74 with a gonotrophic cycle of 4 days. The 2 day difference in gonotrophic cycles between unfed and bloodfed mosquitoes was the result of the period required for maturation and mating of teneral females. In 1986, an incage release of field-collected females estimated survivorship at 0.75 per day. Precipitin tests of 1,338 blood-engorged mosquito abdomens indicated that bovids, horses, rabbits, and canids comprised 92% of bloodmeals; no bloodmeals of human origin were detected.
Address Department of Entomology, University of California, Davis
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ISSN 0002-9637 ISBN Medium
Area Expedition Conference
Notes PMID:2774063 Approved no
Call Number Equine Behaviour @ team @ Serial 2673
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Author Hardy, J.L.
Title The ecology of western equine encephalomyelitis virus in the Central Valley of California, 1945-1985 Type Journal Article
Year 1987 Publication (down) The American Journal of Tropical Medicine and Hygiene Abbreviated Journal Am J Trop Med Hyg
Volume 37 Issue 3 Suppl Pages 18s-32s
Keywords Aedes/microbiology; Animals; Birds; California; Culex/microbiology; Encephalitis Virus, Western Equine/*physiology; Encephalomyelitis, Equine/*history/microbiology/transmission/veterinary; History, 20th Century; Horse Diseases/history/transmission; Horses; Humans; Insect Vectors/microbiology; Mammals
Abstract Reeves' concept of the summer transmission cycle of western equine encephalomyelitis virus in 1945 was that the virus was amplified in a silent transmission cycle involving mosquitoes, domestic chickens, and possibly wild birds, from which it could be transmitted tangentially to and cause disease in human and equine populations. Extensive field and laboratory studies done since 1945 in the Central Valley of California have more clearly defined the specific invertebrate and vertebrate hosts involved in the basic virus transmission cycle, but the overall concept remains unchanged. The basic transmission cycle involves Culex tarsalis as the primary vector mosquito species and house finches and house sparrows as the primary amplifying hosts. Secondary amplifying hosts, upon which Cx. tarsalis frequently feeds, include other passerine species, chickens, and possibly pheasants in areas where they are abundant. Another transmission cycle that most likely is initiated from the Cx. tarsalis-wild bird cycle involves Aedes melanimon and the blacktail jackrabbit. Like humans and horses, California ground squirrels, western tree squirrels, and a few other wild mammal species become infected tangentially with the virus but do not contribute significantly to virus amplification.
Address Department of Biomedical and Environmental Health Sciences, School of Public Health, University of California, Berkeley 94720
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0002-9637 ISBN Medium
Area Expedition Conference
Notes PMID:3318522 Approved no
Call Number Equine Behaviour @ team @ Serial 2677
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