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Author Kaseda, Y.; Ogawa, H.; Khalil, A.M.
Title Causes of natal dispersal and emigration and their effects on harem formation in Misaki feral horses Type Journal Article
Year 1997 Publication Equine Veterinary Journal Abbreviated Journal Equine Vet J
Volume 29 Issue 4 Pages 262-266
Keywords Age Factors; Animal Migration; Animals; Animals, Wild; *Behavior, Animal/physiology; Female; Horses/*physiology/psychology; Male; Reproduction; Seasons; Sexual Behavior, Animal; *Social Behavior
Abstract Misaki feral horses were separated into 2 herds and the difference between dispersal from natal group (natal dispersal) and dispersal from natal area (natal emigration) was studied. The causes of dispersal and emigration and their effects on harem formation were studied 1979-1994. The number of horses ranged from 73 (mature males: 8, mature females: 26, young males: 8, young females: 3, colt foals: 6, filly foals: 10 and geldings: 12) in 1979 and 86 (mature males: 14, mature females: 37, young males: 12, young females: 7, colt foals: 5, filly foals: 7 and geldings: 4) in 1994 when the present study ended. All 29 males which survived to age 4 years and 58 females which survived to age 3 years left their natal or mother groups at age one to 3. Seventeen of 22 dispersing males and 29 of 39 dispersing females left their natal groups around the birth of their siblings and significant correlations were found between natal dispersal and birth of a sibling. The number of emigrating young males correlated negatively and significantly with the total number of young males in another herd and the number of emigrating young females correlated positively and significantly with the total number of young females in the natal herd. All 13 emigrating stallions which survived to age 5 years formed stable harem groups and a significant correlation was found between natal emigration and harem formation. Twenty-three of 35 resident mares formed stable consort relations with harem stallions and a significant correlation was found between residence and formation of stable consort relations.
Address Faculty of Agriculture, Miyazaki University, Miyazaki-shi, 889-21, Japan
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ISSN (up) 0425-1644 ISBN Medium
Area Expedition Conference
Notes PMID:15338905 Approved no
Call Number Equine Behaviour @ team @ Serial 4630
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Author Feist, J.D.; McCullough, D.R.
Title Reproduction in feral horses Type Journal Article
Year 1975 Publication Journal of Reproduction and Fertility. Supplement Abbreviated Journal J Reprod Fertil Suppl
Volume Issue 23 Pages 13-18
Keywords Age Factors; Animals; Female; Horses/*physiology; Leadership; Male; Maternal Behavior; Population; Reproduction; *Sexual Behavior, Animal; Social Dominance; Sucking Behavior
Abstract A behavioural study of feral horses was conducted on the Pryor Mountain Wild Horse Range in the western United States. All 270 horses on the Range were identified individually. The sex ratio was nearly balanced. Foal to adult female ratio was 43-2:100. Morality was concentrated among foals and old horses. Horses were organized as forty-four harem groups each with a dominant stallion, one to two immature stallions, one to three immature mares, one to three adult mares and their yearling and foal offspring, and 23 bachelor groups of one to eight stallions. Harem groups were quite stable year-round because of dominance and leadership by the stallions and group fidelity by mares and their offsring. Most changes occurred during the breeding season and involved immature females. Defeat of dominant stallions was infrequent. Immature males were tolerated because of their submissive behaviour. Bachelor stallion groups were inherently unstable. Mares came into heat after foaling in May/June, and were mated by harem stallions only.
Address
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ISSN (up) 0449-3087 ISBN Medium
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Notes PMID:1060766 Approved no
Call Number refbase @ user @ Serial 1964
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Author Flack, J.C.; Jeannotte, L.A.; de Waal, F.B.M.
Title Play signaling and the perception of social rules by juvenile chimpanzees (Pan troglodytes) Type Journal Article
Year 2004 Publication Journal of comparative psychology (Washington, D.C. : 1983) Abbreviated Journal J Comp Psychol
Volume 118 Issue 2 Pages 149-159
Keywords Age Factors; Animals; Behavior, Animal; Female; Male; Pan troglodytes; *Play and Playthings; Recognition (Psychology); *Signal Detection (Psychology); *Social Perception
Abstract Prescriptive social rules are enforced statistical regularities. The authors investigated whether juvenile chimpanzees (Pan troglodytes) recognize and use enforced statistical regularities to guide dyadic play behavior. They hypothesized (a) that proximity of adults, especially mothers of younger play partners, to play bouts will increase the play signaling of older partners and (b) that when juvenile-juvenile play bouts occur in proximity to adults, older partners will play at a lower intensity than when no adults are present. They found that older and younger partners increase their play signaling in the presence of the mothers of younger partners, particularly as the intensity of play bouts increases. In contrast to their hypothesis, older partners played more roughly when the mothers of younger partners were in proximity. These results suggest that juvenile chimpanzees increase play signaling to prevent termination of the play bouts by mothers of younger partners.
Address Santa Fe Institute, NM 97501, USA. jflack@santafe.edu
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Series Editor Series Title Abbreviated Series Title
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ISSN (up) 0735-7036 ISBN Medium
Area Expedition Conference
Notes PMID:15250802 Approved no
Call Number refbase @ user @ Serial 172
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Author Lilienfeld, S.O.; Gershon, J.; Duke, M.; Marino, L.; de Waal, F.B.
Title A preliminary investigation of the construct of psychopathic personality (psychopathy) in chimpanzees (Pan troglodytes) Type Journal Article
Year 1999 Publication Journal of comparative psychology (Washington, D.C. : 1983) Abbreviated Journal J Comp Psychol
Volume 113 Issue 4 Pages 365-375
Keywords Age Factors; Analysis of Variance; Animals; Antisocial Personality Disorder/*diagnosis/psychology; Ethology/*methods; Female; Male; Observer Variation; Pan troglodytes/*psychology; Psychiatric Status Rating Scales/*standards; Reproducibility of Results; Sex Characteristics; *Social Behavior
Abstract Although the construct of psychopathy has received considerable attention in humans, its relevance to other animals is largely unknown. We developed a measure of psychopathy for use in chimpanzees (Pan troglodytes), the Chimpanzee Psychopathy Measure (CPM), and asked 6 raters to complete this index on 34 chimpanzees. The CPM (a) demonstrated satisfactory interrater reliability and internal consistency; (b) exhibited marginally significant sex differences (males > females); (c) correlated positively with measures of extraversion, agreeableness, and observational ratings of agonism, sexual activity, daring behaviors, teasing, silent bluff displays, and temper tantrums, and negatively with observational ratings of generosity; and (d) demonstrated incremental validity above and beyond a measure of dominance. Although further validation of the CPM is needed, these findings suggest that the psychopathy construct may be relevant to chimpanzees.
Address Department of Psychology, Emory University, Atlanta, Georgia 30322, USA. scott@ss.emory.edu
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ISSN (up) 0735-7036 ISBN Medium
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Notes PMID:10608560 Approved no
Call Number refbase @ user @ Serial 193
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Author Khalil, A.M.; Murakami, N.; Kaseda, Y.
Title Relationship between plasma testosterone concentrations and age, breeding season and harem size in Misaki feral horses Type Journal Article
Year 1998 Publication The Journal of veterinary medical science / the Japanese Society of Veterinary Science Abbreviated Journal J Vet Med Sci
Volume 60 Issue 5 Pages 643-645
Keywords Age Factors; Animals; Animals, Wild; *Horses; Japan; Male; Reproduction; Seasons; Sexual Behavior, Animal; Sexual Maturation; *Social Behavior; Testosterone/*blood
Abstract Jugular vein blood samples were collected from 23 young and sexual mature feral stallions to examine the relationship between plasma testosterone concentration and age, breeding season or harem size. Testosterone concentration increased with the age of the stallions until they formed their own harems, at about 4 to 6 years old. Seasonal variations in testosterone concentrations were observed, and found to be significantly higher (P<0.001) throughout the breeding season than non-breeding season, from 3 years of age. Testosterone levels were correlated with harem size for individual stallions. It can be inferred from these results that there is a relationship between plasma testosterone concentration and age, breeding season and harem size.
Address Laboratory of Animal Behavioral Science, Faculty of Agriculture, Miyazaki University, Japan
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ISSN (up) 0916-7250 ISBN Medium
Area Expedition Conference
Notes PMID:9637303 Approved no
Call Number refbase @ user @ Serial 137
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Author Cameron, E.Z.
Title Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism Type Journal Article
Year 2004 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci
Volume 271 Issue 1549 Pages 1723-1728
Keywords Age Factors; Animals; Body Constitution; *Evolution; Female; Glucose/metabolism/physiology; Litter Size; Male; Mammals/*physiology; *Models, Biological; Reproduction/physiology; Seasons; Sex Factors; *Sex Ratio; Time Factors
Abstract Evolutionary theory predicts that mothers of different condition should adjust the birth sex ratio of their offspring in relation to future reproductive benefits. Published studies addressing variation in mammalian sex ratios have produced surprisingly contradictory results. Explaining the source of such variation has been a challenge for sex-ratio theory, not least because no mechanism for sex-ratio adjustment is known. I conducted a meta-analysis of previous mammalian sex-ratio studies to determine if there are any overall patterns in sex-ratio variation. The contradictory nature of previous results was confirmed. However, studies that investigated indices of condition around conception show almost unanimous support for the prediction that mothers in good condition bias their litters towards sons. Recent research on the role of glucose in reproductive functioning have shown that excess glucose favours the development of male blastocysts, providing a potential mechanism for sex-ratio variation in relation to maternal condition around conception. Furthermore, many of the conflicting results from studies on sex-ratio adjustment would be explained if glucose levels in utero during early cell division contributed to the determination of offspring sex ratios.
Address Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. ezcameron@zoology.up.ac.za
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ISSN (up) 0962-8452 ISBN Medium
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Notes PMID:15306293 Approved no
Call Number refbase @ user @ Serial 413
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Author Call, J.
Title Inferences by exclusion in the great apes: the effect of age and species Type Journal Article
Year 2006 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 9 Issue 4 Pages 393-403
Keywords Age Factors; Animals; Association Learning; *Cognition; *Concept Formation; *Discrimination Learning; Female; Gorilla gorilla; Hominidae/classification/*psychology; Male; Pan paniscus; Pan troglodytes; Pongo pygmaeus; *Problem Solving; Species Specificity
Abstract This study investigated the ability of chimpanzees, gorillas, orangutans, and bonobos to make inferences by exclusion using the procedure pioneered by Premack and Premack (Cognition 50:347-362, 1994) with chimpanzees. Thirty apes were presented with two different food items (banana vs. grape) on a platform and covered with identical containers. One of the items was removed from the container and placed between the two containers so that subjects could see it. After discarding this item, subjects could select between the two containers. In Experiment 1, apes preferentially selected the container that held the item that the experimenter had not discarded, especially if subjects saw the experimenter remove the item from the container (but without seeing the container empty). Experiment 3 in which the food was removed from one of the containers behind a barrier confirmed these results. In contrast, subjects performed at chance levels when a stimulus (colored plastic chip: Exp. 1; food item: Exp. 2 and Exp. 3) designated the item that had been removed. These results indicated that apes made inferences, not just learned to use a discriminative cue to avoid the empty container. Apes perceived and treated the item discarded by the experimenter as if it were the very one that had been hidden under the container. Results suggested a positive relationship between age and inferential ability independent of memory ability but no species differences.
Address Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103, Leipzig, Germany. call@eva.mpg.de
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ISSN (up) 1435-9448 ISBN Medium
Area Expedition Conference
Notes PMID:16924458 Approved no
Call Number Equine Behaviour @ team @ Serial 2444
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Author Borsari, A.; Ottoni, E.B.
Title Preliminary observations of tool use in captive hyacinth macaws (Anodorhynchus hyacinthinus) Type Journal Article
Year 2005 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 8 Issue 1 Pages 48-52
Keywords Age Factors; Animals; *Feeding Behavior; Female; *Intelligence; Male; *Motor Skills; *Nuts; *Parrots
Abstract Many animals use tools (detached objects applied to another object to produce an alteration in shape, position, or structure) in foraging, for instance, to access encapsulated food. Descriptions of tool use by hyacinth macaws (Anodorhynchus hyacinthinus) are scarce and brief. In order to describe one case of such behavior, six captive birds were observed while feeding. Differences in nut manipulation and opening proficiency between adults and juveniles were recorded. The tools may be serving as a wedge, preventing the nut from slipping and/or rotating, reducing the impact of opening, or providing mechanical aid in its positioning and/or use of force. Data suggest that birds of this species have an innate tendency to use objects (tools) as aids during nut manipulation and opening.
Address Laboratory of Cognitive Ethology, Department of Experimental Psychology, Institute of Psychology, University of Sao Paulo, Sao Paulo, Brazil. borsari@hotmail.com
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ISSN (up) 1435-9448 ISBN Medium
Area Expedition Conference
Notes PMID:15248094 Approved no
Call Number Equine Behaviour @ team @ Serial 2518
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Author Imura, T.; Tomonaga, M.
Title Perception of depth from shading in infant chimpanzees ( Pan troglodytes) Type Journal Article
Year 2003 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 6 Issue 4 Pages 253-258
Keywords Age Factors; Animals; Contrast Sensitivity/*physiology; Depth Perception/*physiology; Discrimination Learning/*physiology; Female; Male; Pan troglodytes/growth & development/*physiology/*psychology; Pattern Recognition, Visual/physiology
Abstract We investigated the ability to perceive depth from shading, one of the pictorial depth cues, in three chimpanzee infants aged 4-10 months old, using a preferential reaching task commonly used to study pictorial depth perception in human infants. The chimpanzee infants reached significantly more to three-dimensional toys than to pictures thereof and more to the three-dimensional convex than to the concave. Furthermore, two of the three infants reached significantly more to the photographic convex than to the photographic concave. These infants also looked longer at the photographic convex than the concave. Our results suggest that chimpanzees perceive, at least as early as the latter half of the first year of life, pictorial depth defined by shading information. Photographic convexes contain richer information about pictorial depth (e.g., attached shadow, cast shadow, highlighted area, and global difference in brightness) than simple computer-graphic graded patterns. These cues together might facilitate the infants' perception of depth from shading.
Address Graduate School of Humanities, Kwansei Gakuin University, Uegahara, Nishinomiya, Hyogo 662-8501, Japan
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ISSN (up) 1435-9448 ISBN Medium
Area Expedition Conference
Notes PMID:14610661 Approved no
Call Number Equine Behaviour @ team @ Serial 2550
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Author Hayashi, M.; Matsuzawa, T.
Title Cognitive development in object manipulation by infant chimpanzees Type Journal Article
Year 2003 Publication Animal Cognition Abbreviated Journal Anim. Cogn.
Volume 6 Issue 4 Pages 225-233
Keywords Age Factors; Animals; Child Development/physiology; Child, Preschool; Cognition/*physiology; Female; Growth; Humans; Imitative Behavior/physiology; Infant; Learning/*physiology; Male; Mothers/*psychology; Motor Skills/*physiology; Pan troglodytes/*growth & development/*psychology; Psychomotor Performance/*physiology; Species Specificity
Abstract This study focuses on the development of spontaneous object manipulation in three infant chimpanzees during their first 2 years of life. The three infants were raised by their biological mothers who lived among a group of chimpanzees. A human tester conducted a series of cognitive tests in a triadic situation where mothers collaborated with the researcher during the testing of the infants. Four tasks were presented, taken from normative studies of cognitive development of Japanese infants: inserting objects into corresponding holes in a box, seriating nesting cups, inserting variously shaped objects into corresponding holes in a template, and stacking up wooden blocks. The mothers had already acquired skills to perform these manipulation tasks. The infants were free to observe the mothers' manipulative behavior from immediately after birth. We focused on object-object combinations that were made spontaneously by the infant chimpanzees, without providing food reinforcement for any specific behavior that the infants performed. The three main findings can be summarized as follows. First, there was precocious appearance of object-object combination in infant chimpanzees: the age of onset (8-11 months) was comparable to that in humans (around 10 months old). Second, object-object combinations in chimpanzees remained at a low frequency between 11 and 16 months, then increased dramatically at the age of approximately 1.5 years. At the same time, the accuracy of these object-object combinations also increased. Third, chimpanzee infants showed inserting behavior frequently and from an early age but they did not exhibit stacking behavior during their first 2 years of life, in clear contrast to human data.
Address Section of Language and Intelligence, Primate Research Institute, Kyoto University, 41 Kanrin, Inuyama, 484-8506 Aichi, Japan. misato@pri.kyoto-u.ac.jp
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ISSN (up) 1435-9448 ISBN Medium
Area Expedition Conference
Notes PMID:12905079 Approved no
Call Number Equine Behaviour @ team @ Serial 2559
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