|   | 
Details
   web
Records
Author Lachmann M.; Bergstrom C.T.
Title (up) Signalling among Relatives II. Beyond the Tower of Babel Type Journal Article
Year 1998 Publication Theoretical Population Biology Abbreviated Journal 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 Clement, T.S.; Weaver, J.E.; Sherburne, L.M.; Zentall, T.R.
Title (up) 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 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 Carpenter, M.; Nagell, K.; Tomasello, M.; Butterworth, G.; Moore, C.
Title (up) Social Cognition, Joint Attention, and Communicative Competence from 9 to 15 Months of Age Type Journal Article
Year 1998 Publication Monographs of the Society for Research in Child Development Abbreviated Journal Monogr Soc Res Child Dev
Volume 63 Issue 4 Pages 1-174
Keywords
Abstract At around 1 year of age, human infants display a number of new behaviors that seem to indicate a newly emerging understanding of other persons as intentional beings whose attention to outside objects may be shared, followed into, and directed in various ways. These behaviors have mostly been studied separately. In the current study, we investigated the most important of these behaviors together as they emerged in a single group of 24 infants between 9 and 15 months of age. At each of seven monthly visits, we measured joint attentional engagement, gaze and point following, imitation of two different kinds of actions on objects, imperative and declarative gestures, and comprehension and production of language. We also measured several nonsocial-cognitive skills as a point of comparison. We report two studies. The focus of the first study was the initial emergence of infants' social-cognitive skills and how these skills are related to one another developmentally. We found a reliable pattern of emergence: Infants progressed from sharing to following to directing others' attention and behavior. The nonsocial skills did not emerge predictably in this developmental sequence. Furthermore, correlational analyses showed that the ages of emergence of all pairs of the social-cognitive skills or their components were interrelated. The focus of the second study was the social interaction of infants and their mothers, especially with regard to their skills of joint attentional engagement (including mothers' use of language to follow into or direct infants' attention) and how these skills related to infants' early communicative competence. Our measures of communicative competence included not only language production, as in previous studies, but also language comprehension and gesture production. It was found that two measures-the amount of time infants spent in joint engagement with their mothers and the degree to which mothers used language that followed into their infant's focus of attention-predicted infants' earliest skills of gestural and linguistic communication. Results of the two studies are discussed in terms of their implications for theories of social-cognitive development, for theories of language development, and for theories of the process by means of which human children become fully participating members of the cultural activities and processes into which they are born.
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 3997
Permanent link to this record
 

 
Author Connor, R.C.; Mann, J.; Tyack, P.L.; Whitehead, H.
Title (up) Social evolution in toothed whales Type Journal Article
Year 1998 Publication Trends in Ecology & Evolution Abbreviated Journal 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 McNelis, N.L.; Boatright-Horowitz, S.L.
Title (up) Social monitoring in a primate group: the relationship between visual attention and hierarchical ranks Type Journal Article
Year 1998 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 1 Issue 1 Pages 65-69
Keywords
Abstract Social monitoring has been hypothesized to be an important component of primate social behavior. If the gaze direction of one animal can redirect the gaze of another, visual scanning of conspecifics can provide a more efficient means of locating food or predators than directly scanning the entire nonsocial environment. Social monitoring also allows distance regulation between members of a group, reducing the likelihood of agonistic encounters. Although assessment of gaze direction in freely moving primates is problematic, we were successful in assessing amounts of visual scanning among adult females of a captive, socially housed group of patas monkeys (Erythrocebus patas) using a focal sampling technique with on-the-dot recording (5-s sampling intervals). In study 1, relative amounts of scanning were assessed as subjects gazed at any other member of the group. Percentages of agreement between observers ranged from 80% to 92%, with corresponding &#115 values ranging from 0.74 to 0.92. In study 2, relative amounts of visual scanning were assessed so that specific targets of gaze were identified. The resultant data supported a long-standing prediction about the role of social monitoring in primate group dynamics. Lower-ranking animals gazed toward higher-ranking animals more often than vice versa. Although the specific cues eliciting social monitoring remain to be determined, visual attention in this social primate group appeared to be systematically related to hierarchical ranks, assessed by displacements. Minimally, these results suggest that patas monkeys structure their visual attention based on previous encounters with other members of their social group. While simple discrimination learning could account for these results, the demonstration of a systematic relationship between visual attention and primate social dynamics is relevant to current discussions of a primate's understanding of conspecific gaze direction.
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 3377
Permanent link to this record
 

 
Author Dyer, F.C.
Title (up) Spatial Cognition: Lessons from Central-place Foraging Insects Type Book Chapter
Year 1998 Publication Animal Cognition in Nature Abbreviated Journal
Volume Issue Pages 119-154
Keywords
Abstract Summary Spatial orientation has played an extremely important role in the development of ideas about the behavioral capacities of animals. Indeed, as the modern scientific study of animal behavior emerged from its roots in zoology and experimental psychology, studies of spatial orientation figured in the work of many of the pioneering researchers, including Tinbergen (), von ), Watson () and .
Address
Corporate Author Thesis
Publisher Academic Press Place of Publication London Editor Russell P. Balda; Irene M. Pepperberg; Alan C. Kamil
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 9780120770304 Medium
Area Expedition Conference
Notes Approved no
Call Number Equine Behaviour @ team @ Serial 2913
Permanent link to this record
 

 
Author Peters, G.; Tembrock, G.
Title (up) Subharmonics, biphonation, and deterministic chaos in mammal vocalizations Type Journal Article
Year 1998 Publication Bioacoustics Abbreviated Journal
Volume 9 Issue Pages
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 Equine Behaviour @ team @ Peters1998 Serial 6483
Permanent link to this record
 

 
Author Blunden, A.S.; Smith, K.C.; Whitwell, K.E.; Dunn, K.A.
Title (up) Systemic infection by equid herpesvirus-1 in a Grevy's zebra stallion (Equus grevyi) with particular reference to genital pathology Type Journal Article
Year 1998 Publication Journal of Comparative Pathology Abbreviated Journal J Comp Pathol
Volume 119 Issue 4 Pages 485-493
Keywords Animals; Animals, Zoo; Epididymis/pathology/virology; Equidae/*virology; Herpesviridae Infections/diagnosis/pathology/*veterinary; Herpesvirus 1, Equid/isolation & purification/*pathogenicity; Lymph Nodes/pathology/virology; Male; Nasal Mucosa/pathology/virology; Pulmonary Edema/pathology; Spleen/virology; Testis/*pathology/virology
Abstract A severe multi-systemic form of equid herpesvirus-1 infection is described in an adult zebra stallion. There was multifocal necrotizing rhinitis, marked hydrothorax and pulmonary oedema, with viral antigen expression in degenerating epithelial cells, local endothelial cells and intravascular leucocytes of the nasal mucosa and lung. Specific localization of EHV-1 infection was seen in the testes and epididymides, including infection of Leydig cells and germinal epithelium, which would have facilitated venereal shedding of virus in life. The case provided a unique opportunity to study hitherto undescribed aspects of the pathogenesis of naturally occurring EHV-1 infection in the male equine genital tract. Restriction digests of the isolate demonstrated a pattern similar to that of EHV-1 isolates previously recovered from aborted zebra and onager fetuses.
Address Animal Health Trust Centre for Preventive Medicine, Newmarket, Suffolk, UK
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 0021-9975 ISBN Medium
Area Expedition Conference
Notes PMID:9839210 Approved no
Call Number Equine Behaviour @ team @ Serial 2239
Permanent link to this record
 

 
Author Boyd, L.
Title (up) The 24-h time budget of a takh harem stallion (Equus ferus przewalskii) pre- and post-reintroduction Type Journal Article
Year 1998 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.
Volume 60 Issue 4 Pages 291-299
Keywords Takhi; Przewalski's horse; Asian wild horse; Mongolian wild horse; Time budget; Reintroduction
Abstract Focal animal sampling was used to determine the 24-h time budget of a takh harem stallion (Equus ferus przewalskii) during the 2 weeks prior to, and the two weeks following, reintroduction into the Hustain Nuruu Steppe Reserve, Mongolia. Both before and after release, the stallion spent approximately 47% of his time grazing, 6% standing, and 5% in recumbent rest. The biggest changes to the time budget after release were a 4-fold increase in the amount of time spent moving, and a 50% decrease in the amount of time spent resting in a standing position. During the middle of the day when the temperatures were hottest, the stallion exhibited less grazing and more standing resting behaviour than in the morning or evening hours. Recumbent rest invariably occurred in the hours before dawn.
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 2245
Permanent link to this record
 

 
Author Moehlman, P.D.; Kebede, F.; Yohannes, H.
Title (up) The African wild ass (Equus africanus): conservation status in the horn of Africa Type Journal Article
Year 1998 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.
Volume 60 Issue 2-3 Pages 115-124
Keywords Equus africanus; Critically endangered; Extinction
Abstract From 1989 to 1996, surveys were made in most of the historic range of African wild asses in Somalia, Ethiopia, and Eritrea. From the 1970s to the mid 1990s populations of African wild asses (Equus africanus, Fitzinger, 1857) in Somalia and Ethiopia have declined from approximately 6 to 30 per 100 km2 to 1 or 2 per 100 km2. Given the current IUCN criteria, they are Critically Endangered (CR) and face extremely high risk of extinction in the wild in the immediate future, as their populations have been reduced by at least 80% over the last 10+ years (IUCN, 1994). Basic research is needed on this species as scientific information on its reproductive biology, behavior, ecology, and genetics is very limited. Improved support needs to be provided to existing parks and reserves and new multiple use reserves need to be established.
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 2380
Permanent link to this record