toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Bergstrom, C.T.; Lachmann, M. openurl 
  Title Signaling among relatives. III. Talk is cheap Type Journal Article
  Year 1998 Publication Proceedings of the National Academy of Sciences of the United States of America Abbreviated Journal (up) Proc. Natl. Acad. Sci. U.S.A.  
  Volume 95 Issue 9 Pages 5100-5105  
  Keywords Animal Communication; Animals; Costs and Cost Analysis; *Evolution; Interpersonal Relations; Models, Biological  
  Abstract The Sir Philip Sidney game has been used by numerous authors to show how signal cost can facilitate honest signaling among relatives. Here, we demonstrate that, in this game, honest cost-free signals are possible as well, under very general conditions. Moreover, these cost-free signals are better for all participants than the previously explored alternatives. Recent empirical evidence suggests that begging is energetically inexpensive for nestling birds; this finding led some researchers to question the applicability of the costly signaling framework to nestling begging. Our results show that cost-free or inexpensive signals, as observed empirically, fall within the framework of signaling theory.  
  Address Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA. carl@charles.stanford.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 0027-8424 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:9560235 Approved no  
  Call Number refbase @ user @ Serial 561  
Permanent link to this record
 

 
Author Dugatkin, L.A. url  doi
openurl 
  Title Breaking up fights between others: a model of intervention behaviour Type Journal Article
  Year 1998 Publication Proceedings of the Royal Society of London. Series B: Biological Sciences Abbreviated Journal (up) Proc. R. Soc. Lond. B  
  Volume 265 Issue 1394 Pages 433-437  
  Keywords  
  Abstract To examine when and why animals break up fights between others in their group, I modelled whether ‘winner’ and ‘loser’ effects might be one element driving the evolution of intervention behaviour. I considered one particular type of intervention: when the intervener simply breaks up fights between two others, but does not favour either party in so doing. When victories at time T + 1 are more likely given a victory at time T (i.e. winner effects), intervention is often favoured. Intervention is favoured in these circumstances because the intervening party in essence stops others from ‘getting on a roll’ and climbing up any hierarchy that exists. However, when loser effects alone are at work (defeats at time T + 1 are more likely given a defeat at time T), breaking up fights between others is never selected. If both winner and loser effects are operating simultaneously, then the likelihood of intervention behaviour evolving is a function of the relative strength of these two effects. The greater the winner effect relative to the loser effect, the more likely intervention behaviour is to evolve.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes 10.1098/rspb.1998.0313 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5240  
Permanent link to this record
 

 
Author Oliveira, R. F.; McGregor, P.K.; Latruffe, C. doi  openurl
  Title Know thine enemy: fighting fish gather information from observing conspecific interactions Type Journal Article
  Year 1998 Publication Proceedings of the Royal Society B: Biological Sciences Abbreviated Journal (up) Proc. Roy. Soc. Lond. B Biol. Sci.  
  Volume 265 Issue 1401 Pages 1045-1049  
  Keywords  
  Abstract Many of the signals that animals use to communicate transmit relatively large distances and therefore encompass several potential signallers and receivers. This observation challenges the common characterization of animal communication systems as consisting of one signaller and one receiver. Furthermore, it suggests that the evolution of communication behaviour must be considered as occurring in the context of communication networks rather than dyads. Although considerations of selection pressures acting upon signallers in the context of communication networks have rarely been expressed in such terms, it has been noted that many signals exchanged during aggressive interactions will transmit far further than required for information transfer between the individuals directly involved, suggesting that these signals have been designed to be received by other, more distant, individuals. Here we consider the potential for receivers in communication networks to gather information, one aspect of which has been termed eavesdropping. We show that male Betta splendens monitor aggressive interactions between neighbouring conspecifics and use the information on relative fighting ability in subsequent aggressive interactions with the males they have observed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 2168  
Permanent link to this record
 

 
Author Clement, T.S.; Weaver, J.E.; Sherburne, L.M.; Zentall, T.R. openurl 
  Title Simultaneous discrimination learning in pigeons: value of S- affects the relative value of its associated S+ Type Journal Article
  Year 1998 Publication The Quarterly journal of experimental psychology. B, Comparative and physiological psychology Abbreviated Journal (up) Q J Exp Psychol B  
  Volume 51 Issue 4 Pages 363-378  
  Keywords Animals; *Attention; Color Perception; Columbidae; *Discrimination Learning; Female; Male; *Motivation; Orientation; Transfer (Psychology)  
  Abstract In a simple simultaneous discrimination involving a positive stimulus (S+) and a negative stimulus (S-), it has been hypothesized that positive value can transfer from the S+ to the S- (thus increasing the relative value of the S-) and also that negative value can transfer from the S- to the S+ (thus diminishing the relative value of the S+; Fersen, Wynne, Delius, & Staddon, 1991). Evidence for positive value transfer has been reported in pigeons (e.g. Zentall & Sherburne, 1994). The purpose of the present experiments was to determine, in a simultaneous discrimination, whether the S- diminishes the value of the S+ or the S- is contrasted with the S+ (thus enhancing the value of the S+). In two experiments, we found evidence for contrast, rather than value transfer, attributable to simultaneous discrimination training. Thus, not only does the S+ appear to enhance the value of the S-, but the S- appears to enhance rather than reduce the value of the S+.  
  Address Department of Psychology, University of Kentucky, Lexington 40506-0044, USA  
  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 0272-4995 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:9854439 Approved no  
  Call Number refbase @ user @ Serial 252  
Permanent link to this record
 

 
Author Brannon, E.M.; Terrace, H.S. openurl 
  Title Ordering of the numerosities 1 to 9 by monkeys Type Journal Article
  Year 1998 Publication Science (New York, N.Y.) Abbreviated Journal (up) Science  
  Volume 282 Issue 5389 Pages 746-749  
  Keywords Animals; *Discrimination (Psychology); Macaca mulatta/*psychology; *Mathematics; *Mental Processes  
  Abstract A fundamental question in cognitive science is whether animals can represent numerosity (a property of a stimulus that is defined by the number of discriminable elements it contains) and use numerical representations computationally. Here, it was shown that rhesus monkeys represent the numerosity of visual stimuli and detect their ordinal disparity. Two monkeys were first trained to respond to exemplars of the numerosities 1 to 4 in an ascending numerical order (1 --> 2 --> 3 --> 4). As a control for non-numerical cues, exemplars were varied with respect to size, shape, and color. The monkeys were later tested, without reward, on their ability to order stimulus pairs composed of the novel numerosities 5 to 9. Both monkeys responded in an ascending order to the novel numerosities. These results show that rhesus monkeys represent the numerosities 1 to 9 on an ordinal scale.  
  Address Department of Psychology, Columbia University, New York, NY 10027, USA. liz@psych.columbia.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 0036-8075 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:9784133 Approved no  
  Call Number refbase @ user @ Serial 606  
Permanent link to this record
 

 
Author Lachmann M.; Bergstrom C.T. url  openurl
  Title Signalling among Relatives II. Beyond the Tower of Babel Type Journal Article
  Year 1998 Publication Theoretical Population Biology Abbreviated Journal (up) Theor. Pop. Biol.  
  Volume 54 Issue 2 Pages 146-160  
  Keywords  
  Abstract Models of costly signalling are commonly employed in evolutionary biology in order to explain how honest communication between individuals with conflicting interests can be stable. These models have focused primarily on a single type of honest signalling equilibrium, the separating equilibrium in which any two different signallers send distinct signals, thereby providing signal receivers with complete information. In this paper, we demonstrate that in signalling among relatives (modelled using the Sir Philip Sidney game), there is not one but a large number of possible signalling equilibria, most of which are pooling equilibria in which different types of signallers may share a common signal. We prove that in a general Sir Philip Sidney game, any partition of signallers into equi-signalling classes can have a stable signalling equilibrium if and only if it is a contiguous partition, and provide examples of such partitions. A similar (but slightly stricter) condition is shown to hold when signals are transmitted through a medium with signalling error. These results suggest a solution to a problem faced by previous signalling theory models: when we consider the separating equilibrium, signal cost is independent of the frequency of individuals sending that signal and, consequently, even very rare signaller types can drastically affect signal cost. Here, we show that by allowing these rare signallers to pool with more common signallers, signal cost can be greatly reduced. Copyright 1998 Academic Press.  
  Address  
  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 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 560  
Permanent link to this record
 

 
Author McLaren I.P.L. doi  openurl
  Title Animal Learning and Cognition: A neural network approach Type Journal Article
  Year 1998 Publication Trends in Cognitive Sciences Abbreviated Journal (up) Trends. Cognit. Sci.  
  Volume 2 Issue Pages 236-236  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 3464  
Permanent link to this record
 

 
Author Vallortigara G. doi  openurl
  Title Minds of Their Own Type Journal Article
  Year 1998 Publication Trends in Cognitive Sciences Abbreviated Journal (up) Trends. Cognit. Sci.  
  Volume 2 Issue Pages 118-118  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number refbase @ user @ Serial 3466  
Permanent link to this record
 

 
Author Connor, R.C.; Mann, J.; Tyack, P.L.; Whitehead, H. url  doi
openurl 
  Title Social evolution in toothed whales Type Journal Article
  Year 1998 Publication Trends in Ecology & Evolution Abbreviated Journal (up) Trends. Ecol. Evol  
  Volume 13 Issue 6 Pages 228-232  
  Keywords odontocetes; toothed whales; social evolution; communication; bottlenose dolphins; sperm whales; long-term studies; foraging  
  Abstract Two contrasting results emerge from comparisons of the social systems of several odontocetes with terrestrial mammals. Researchers have identified remarkable convergence in prominent features of the social systems of odontocetes such as the sperm whale and bottlenose dolphin with a few well-known terrestrial mammals such as the elephant and chimpanzee. In contrast, studies on killer whales and Baird's beaked whale reveal novel social solutions to aquatic living. The combination of convergent and novel features in odontocete social systems promise a more general understanding of the ecological determinants of social systems in both terrestrial and aquatic habitats, as well as the relationship between relative brain size and social evolution.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0169-5347 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4789  
Permanent link to this record
 

 
Author Heitkamp, H.C.; Horstmann, T.; Hillgeris, D. openurl 
  Title [Riding injuries and injuries due to handling horses in experienced riders] Type Journal Article
  Year 1998 Publication Der Unfallchirurg Abbreviated Journal (up) Unfallchirurg  
  Volume 101 Issue 2 Pages 122-128  
  Keywords Adult; Animals; Athletic Injuries/*epidemiology/etiology/surgery; Cross-Sectional Studies; Female; Fractures, Bone/epidemiology/etiology/surgery; Germany/epidemiology; *Horses; Humans; Incidence; Male; Multiple Trauma/epidemiology/etiology/surgery; Risk Factors  
  Abstract A group of experienced riders who qualified for the German riding badge 9.5 years ago answered a questionnaire pertaining to injuries during jumping, dressage and cross-country riding, as well as handling the horse. During riding 69% of the persons had had 187 injuries and while handling the horse 52% had had 124 injuries. Fractures and contusions were the most-frequent injuries; most riding injuries were located in the upper extremities and shoulder while handling mainly in the hands and feet. The number of injuries was comparable in jumping, dressage or cross-country riding. The time engaged in jumping was about one-third of the other types of riding, but the injuries were more severe. While handling the horse the number of injuries relative to the time spent during the activity were higher but less complicated. No change in safety precautions had been implemented by 67% of the persons injured. The injury rate for equestrians is relatively low both in handling the horse and during riding. The frequent fractures and contusions may be reduced by following the required safety regulations.  
  Address Abteilung Sportmedizin, Universitat Tubingen  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language German Summary Language Original Title Reitverletzungen und Verletzungen beim Umgang mit Pferden bei erfahrenen Reitern  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0177-5537 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:9553480 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3735  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print