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Author Mesterton-Gibbons, M.; Dugatkin, L.A. url  openurl
  Title (up) Cooperation and the Prisoner's Dilemma: towards testable models of mutualism versus reciprocity Type Journal Article
  Year 1997 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 54 Issue 3 Pages 551-557  
  Keywords  
  Abstract For the purpose of distinguishing between mutualism and reciprocity in nature, recent work on the evolution of cooperation has both oversimplifed and undersimplified the distinction between these two categories of cooperation. This article addresses the resulting issues of model testability, clarifies the role of time and argues that the category of `pseudo-reciprocity' is an unnecessary complication.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 480  
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Author Bekoff M. url  openurl
  Title (up) Deep Ethology, Animal Rights, and the Great Ape/Animal Project: Resisting Speciesism and Expanding the Community of Equals Type Journal Article
  Year 1997 Publication Journal of Agricultural and Environmental Ethics Abbreviated Journal  
  Volume 10 Issue Pages 269-296  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 3470  
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Author Foster, T.M.; Temple, W.; Cameron, B.; Poling, A. url  openurl
  Title (up) Demand curves for food in hens: Similarity under fixed-ratio and progressive-ratio schedules Type Journal Article
  Year 1997 Publication Behavioural Processes Abbreviated Journal Behav. Process.  
  Volume 39 Issue 2 Pages 177-185  
  Keywords Progressive-ratio schedule; Fixed-ratio schedule; Demand curves; Behavioral economics; Animal welfare; Keypecking; Chickens  
  Abstract Demand curves were generated for five domestic hens under progressive-ratio 5 schedules of food delivery and under fixed-ratio schedules of food delivery that began at fixed-ratio 5 and were incremented by 5 each session. All sessions ended after 10 consecutive minutes without a response. Although response rates at a given ratio were higher under the progressive-ratio schedule, all hens completed higher ratios under the fixed-ratio schedule. Similar, but not identical, demand curves were generated under progressive-ratio and fixed-ratio schedules. Under both schedules, consumption (reinforcers earned) decreased as cost (ratio size) increased. Data generally were well described by an equation in which elasticity of demand is constant, although an equation in which elasticity could vary accounted for slightly more of the variance.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 3603  
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Author Inoue-Nakamura N; Matsuzawa T openurl 
  Title (up) Development of stone tool use by wild chimpanzees (Pan troglodytes) Type Journal Article
  Year 1997 Publication J. Comp. Psychol. Abbreviated Journal  
  Volume 111 Issue Pages 159  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 3009  
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Author Rogers, L.J. url  doi
openurl 
  Title (up) Early Experiential Effects on Laterality: Research on Chicks has Relevance to Other Species Type Journal Article
  Year 1997 Publication Laterality Abbreviated Journal Laterality  
  Volume 2 Issue 3-4 Pages 199-219  
  Keywords  
  Abstract The influence of early experience on the development of lateralisation of hemispheric function was further investigated, using the chick as a model. A range of functions are lateralised in the chick and these correlate with asymmetry in the organisation of the visual projections. Chicks using the right eye and, therefore, primarily the left hemisphere are able to switch from pecking randomly at grain and pebbles to pecking mainly at grain, whereas those using the left eye and primarily the right hemisphere continue to peck at random. Exposure to light during the last days of incubation establishes this lateralisation in males, as a consequence of the embryo being oriented in the egg so that the left eye only is occluded. Males incubated in the dark peck at random when using either the right or left eye. Irrespective of light experience, females perform the same as darkincubated males: they are not influenced by light exposure. Monocular performance of the pebble-grain task is compared to binocular performance, and the sensitive period for the influence of light is delineated. The interactive effects of sex hormone levels on the differentiation of lateralisation are discussed and also the relevance of the results to other species, including humans.  
  Address  
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  Publisher Psychology Press Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1357-650x ISBN Medium  
  Area Expedition Conference  
  Notes doi: 10.1080/713754277 Approved no  
  Call Number Equine Behaviour @ team @ Serial 5587  
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Author Holmstrom, M.; Drevemo, S. openurl 
  Title (up) Effects of trot quality and collection on the angular velocity in the hindlimbs of riding horses Type Journal Article
  Year 1997 Publication Equine Veterinary Journal. Supplement Abbreviated Journal Equine Vet J Suppl  
  Volume Issue 23 Pages 62-65  
  Keywords Animals; Femur/physiology; Gait/*physiology; Hindlimb/*physiology; Horses/*physiology; Locomotion/*physiology; Male; Movement/physiology; Statistics; Time Factors  
  Abstract The angular velocities of the hindlimb angles of 14 horses, including 6 Grand Prix dressage horses, 4 horses judged as good at the trot and 4 horses judged as poor, were analysed. The horse material was the same as previously used by Holmstrom (1994) in studies on conformation and trotting gaits in the Swedish Warmblood riding horse. Four consecutive strides of each horse and the corresponding pace were analysed and mean velocity curves (Xh) for each angle were calculated. Before calculation the data were filtered forwards and backwards with a Butterworth third order filter with a cut off frequency of 60 Hz. During the last 60% of the stance phase there were differences between the horses judged as good and poor at the trot in all the analysed hindlimb angles except the femur inclination. The angular velocity in the hock joint, pelvis inclination and hindlimb pendulation was larger in the good horses. The angular velocity of the hindlimb pendulation decreased with collection in the Grand Prix horses. During parts of the stance phase, there was also a gradual decrease in the femur angular velocity from trot at hand to piaffe. In the hock joint, there was no difference in angular velocity between trot at hand and passage during the last 30%. The higher compression of the hock angle and pelvic angle to the horizontal plane probably reflects a higher compression of the whole hindlimb. It probably contributes to the greater springiness in the movements of good young horses and Grand Prix dressage horses. The results from the present study confirmed the importance of storing elastic strain energy for the quality of the dressage horse gaits.  
  Address Dept. of Anatomy and Histology, Swedish University of Agricultural Science, Uppsala  
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  Notes PMID:9354292 Approved no  
  Call Number Equine Behaviour @ team @ Serial 3736  
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Author Szenci, O.; Palme, R.; Taverne, M.A.; Varga, J.; Meersma, N.; Wissink, E. openurl 
  Title (up) Evaluation of false ultrasonographic pregnancy diagnoses in sows by measuring the concentration of unconjugated estrogens in feces Type Journal Article
  Year 1997 Publication Theriogenology Abbreviated Journal Theriogenology  
  Volume 48 Issue 5 Pages 873-882  
  Keywords  
  Abstract On Days 26, 28, and 30 after AI, ultrasonographic pregnancy diagnoses were performed on 207 gilts and sows by using a 3.5 MHz linear-array transducer. Fecal samples were taken from the rectum after each ultrasonographic examination, and the concentrations of unconjugated estrogens in selected samples (n = 73) were measured by RIA. Fecal unconjugated estrogen concentration of 11.7 ng/g feces or higher was indicative of pregnancy. The overall sensitivity and specificity of the ultrasonographic test was 99% for farrowing sows and 73.1% for nonfarrowing sows. With one exception, sows with a false negative diagnosis by ultrasonography on Day 26 were correctly diagnosed pregnant by elevated fecal unconjugated estrogens or repeated ultrasonographic examinations on Days 28 or 30. Return to estrus around the sampling period may cause false positive results in the unconjugated estrogen assay, while early embryonic mortality can result in false positive diagnoses in both the ultrasonographic test and estrogen assay. Although there was a positive correlation between the concentrations of unconjugated estrogens in the feces and litter size at farrowing in the selected sows, it seems very unlikely that fecal estrogens can provide an accurate tool for predicting litter size.  
  Address University of Veterinary Science, Department of Obstetrics and Reproduction H-1400 Budapest, P.O. Box 2, Hungary  
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  Series Volume Series Issue Edition  
  ISSN 0093-691X ISBN Medium  
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  Notes PMID:16728179 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4077  
Permanent link to this record
 

 
Author Di Bitetti, M.S. url  doi
openurl 
  Title (up) Evidence for an important social role of allogrooming in a platyrrhine primate Type Journal Article
  Year 1997 Publication Animal Behaviour. Abbreviated Journal Anim. Behav.  
  Volume 54 Issue 1 Pages 199-211  
  Keywords  
  Abstract Allogrooming behaviour was analysed in a wild group of tufted capuchin monkeys,Cebus apellain Iguazu National Park, Argentina. Evidence is provided that allogrooming in this platyrrhine species serves an important social function, as has been demonstrated for catarrhine primates. Using ad libitum sampling, 654 grooming sessions were recorded during 740 contact hours with one group. Seasonal variation was found in daily time allocation to allogrooming and the mean duration and reciprocity of sessions. Individual dominance rank was an important determinant of grooming relationships. The dominant male and female were the most actively involved in grooming. Among adults, dominant individuals were involved in more sessions than were subordinate individuals. The females maintained strong grooming relationships with each other and tended to reciprocate more within sessions than did males. Oestrous females engaged in more grooming bouts with adult males than did non-oestrous females. Females with newborn infants were attractive social partners for the remaining members of the group. A social function for allogrooming inCebusis indicated by the close relationship between allogrooming, the social system and coalition formation, and by the changes in quantity and direction of grooming in response to oestrous behaviour and to the birth of infants.  
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  Notes Approved no  
  Call Number Serial 2079  
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Author Reeve, H. Kern url  doi
openurl 
  Title (up) Evolutionarily stable communication between kin: a general model Type Journal Article
  Year 1997 Publication Proceedings of the Royal Society B: Biological Sciences Abbreviated Journal Proc. Roy. Soc. Lond. B Biol. Sci.  
  Volume 264 Issue (1384) Pages 1037-1040.  
  Keywords Signalling Systems  
  Abstract At present, the most general evolutionary theory of honest communication is Grafen's model of Zahavi's 'handicap' signalling system, in which honesty of signals about the signaller's quality (e.g. mate suitability or fighting ability) is maintained by the differentially high cost of signals to signallers having lower quality. The latter model is here further generalized to include any communication between signallers and receivers that are genetically related (e.g. parents and begging offspring, cooperative or competing siblings). Signalling systems involving relatives are shown to be evolutionarily stable, despite a potential pay-off for false signalling, if the Zahavian assumption of differential signal costs holds and there are diminishing reproductive returns to the signaller as the receiver's assessed value of its attribute increases, or if, regardless of whether the Zahavian assumption holds, signallers with high values of the attribute benefit more from a given receiver assessment than signallers with low values (e.g. begging chicks that are hungrier benefit more from being fed). In stable systems of signalling among kin, it is also shown to be generally true that (i) levels of signalling and thus observed signal costs will decline as relatedness increases or as the receiver's reproductive penalty for erroneous assessment increases, and (ii) receivers will consistently, altruistically overestimate the true value of the signalled attribute.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 557  
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Author Williams, N. openurl 
  Title (up) Evolutionary psychologists look for roots of cognition Type
  Year 1997 Publication Science (New York, N.Y.) Abbreviated Journal Science  
  Volume 275 Issue 5296 Pages 29-30  
  Keywords Animals; *Behavior, Animal; Birds; *Cognition; *Evolution; Female; Humans; Macaca mulatta/psychology; Male; Memory; Reward; *Social Sciences  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0036-8075 ISBN Medium  
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  Notes PMID:8999531 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2845  
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