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Author |
Kaseda, Y.; Ogawa, H.; Khalil, A.M. |
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Title |
Causes of natal dispersal and emigration and their effects on harem formation in Misaki feral horses |
Type |
Journal Article |
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Year |
1997 |
Publication |
Equine Veterinary Journal |
Abbreviated Journal |
Equine Vet J |
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Volume |
29 |
Issue |
4 |
Pages |
262-266 |
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Keywords |
Age Factors; Animal Migration; Animals; Animals, Wild; *Behavior, Animal/physiology; Female; Horses/*physiology/psychology; Male; Reproduction; Seasons; Sexual Behavior, Animal; *Social Behavior |
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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. |
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Faculty of Agriculture, Miyazaki University, Miyazaki-shi, 889-21, Japan |
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0425-1644 |
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PMID:15338905 |
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Equine Behaviour @ team @ |
Serial |
4630 |
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Author |
Imura, T.; Tomonaga, M. |
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Title |
Perception of depth from shading in infant chimpanzees ( Pan troglodytes) |
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Journal Article |
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Year |
2003 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
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Volume |
6 |
Issue |
4 |
Pages |
253-258 |
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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 |
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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. |
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Graduate School of Humanities, Kwansei Gakuin University, Uegahara, Nishinomiya, Hyogo 662-8501, Japan |
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1435-9448 |
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PMID:14610661 |
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Equine Behaviour @ team @ |
Serial |
2550 |
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Author |
Bell, R.J.W.; Kingston, J.K.; Mogg, T.D.; Perkins, N.R. |
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Title |
The prevalence of gastric ulceration in racehorses in New Zealand |
Type |
Journal Article |
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Year |
2007 |
Publication |
New Zealand Veterinary Journal |
Abbreviated Journal |
N Z Vet J |
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Volume |
55 |
Issue |
1 |
Pages |
13-18 |
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Keywords |
Age Factors; *Animal Feed; Animal Husbandry/methods; Animals; Female; Horse Diseases/*epidemiology/pathology/prevention & control; Horses; Male; New Zealand/epidemiology; Physical Conditioning, Animal/*adverse effects/physiology; Poaceae; Prevalence; Risk Factors; Severity of Illness Index; Sex Factors; Stomach Ulcer/epidemiology/pathology/prevention & control/*veterinary; Time Factors |
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AIM: To establish the prevalence and factors influencing the prevalence and severity of gastric ulceration in racehorses in New Zealand. METHODS: Horses (n=171) in active training for racing by trainers (n=24) located throughout New Zealand were examined using gastroscopy during 2003 and 2004. Images of the examination were recorded and reviewed, and an ordinal grade based on the severity of gastric ulceration present was assigned, using the grading system proposed by the Equine Gastric Ulcer Council (EGUC). Information about the horses such as age, breed, sex, stabling, time at pasture, pasture quality, and presence of clinical signs consistent with equine gastric ulcer syndrome (EGUS) was recorded. RESULTS: Of the 171 horses in the study, 133 (78%) were Thoroughbreds and 38 (22%) were Standardbreds. Evidence of gastric ulceration was present in 151 (88.3%) of these. Prevalence of ulceration was higher at the lesser curvature (LC) and greater curvature (GC) of the stomach than at the saccus caecus (SC; p<0.01), and ulceration was more severe at the LC than at either the GC (p=0.02) or the SC (p<0.001). The prevalence of ulceration did not differ between the two breeds (p=0.51) or between horses of differing ages (p=0.56). Gastric ulceration was evident in 125/141 (89%) horses kept at pasture for at least 4 h/day, in all 13 (100%) horses kept at pasture full time, and in 16/17 (94%) horses stabled full time. Prevalence and severity of ulceration did not differ between horses stabled full time, kept at pasture for part of the day or kept at pasture full time (p=0.33 and 0.13, respectively), and for horses grazed on pasture severity of ulceration did not vary significantly with the quality of the pasture (p=0.12). Neither prevalence (p=0.26) nor severity (p=0.49) of gastric ulceration varied significantly with duration of training. CONCLUSIONS: The prevalence of gastric ulceration in racehorses in New Zealand is similar to that reported elsewhere for horses in active training for racing. Access to pasture for some or all of the day did not appear to be protective. |
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Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand. robinjw@gmail.com |
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0048-0169 |
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PMID:17339911 |
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Call Number |
Equine Behaviour @ team @ |
Serial |
4020 |
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Author |
Rapin, V.; Poncet, P.A.; Burger, D.; Mermod, C.; Richard, M.A. |
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Title |
[Measurement of the attention time in the horse] |
Type |
Journal Article |
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Year |
2007 |
Publication |
Schweizer Archiv fur Tierheilkunde |
Abbreviated Journal |
Schweiz Arch Tierheilkd |
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Volume |
149 |
Issue |
2 |
Pages |
77-83 |
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Keywords |
Age Factors; Animals; *Attention/physiology; Conditioning, Operant; Cross-Over Studies; Female; Horses/*physiology; Learning/*physiology; Male; Memory/*physiology; Time Factors |
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Abstract |
A study carried out on 49 horses showed that it is possible to measure the attention time by operant conditioning. After teaching horses an instrumental task using a signal, we were then able to test their attention time by asking them to prolong it increasingly while setting success and failure criteria. Two tests were performed 3 weeks apart. The 2nd test was feasible without relearning, a proof of memory, and was repeatable, a proof of consistency in the attention time. A significant difference was observed between the 3 age groups. Young horses often performed very well during the 1st test but their attention dropped in the 2nd test while older horses were more stable with respect to attention and even increased it slightly. The study shows that there are individual differences but it was not possible to prove a significant influence of breed, gender and paternal influence. Consequently, learning appears to be one of the most interesting approaches for evaluating the attention of horses and for observing their behaviour. |
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Laboratoire d'Ecoethologie, Universite de Neuchatel, Suisse. veronique.rapin@unine.ch |
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French |
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Mesure de la duree d'attention chez le cheval |
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0036-7281 |
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PMID:17343134 |
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no |
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Serial |
1770 |
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Author |
Khalil, A.M.; Murakami, N.; Kaseda, Y. |
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Title |
Relationship between plasma testosterone concentrations and age, breeding season and harem size in Misaki feral horses |
Type |
Journal Article |
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Year |
1998 |
Publication |
The Journal of veterinary medical science / the Japanese Society of Veterinary Science |
Abbreviated Journal |
J Vet Med Sci |
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Volume |
60 |
Issue |
5 |
Pages |
643-645 |
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Keywords |
Age Factors; Animals; Animals, Wild; *Horses; Japan; Male; Reproduction; Seasons; Sexual Behavior, Animal; Sexual Maturation; *Social Behavior; Testosterone/*blood |
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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. |
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Laboratory of Animal Behavioral Science, Faculty of Agriculture, Miyazaki University, Japan |
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ISSN |
0916-7250 |
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Notes |
PMID:9637303 |
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no |
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Call Number |
refbase @ user @ |
Serial |
137 |
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Author |
Borsari, A.; Ottoni, E.B. |
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Title |
Preliminary observations of tool use in captive hyacinth macaws (Anodorhynchus hyacinthinus) |
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Journal Article |
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Year |
2005 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
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Volume |
8 |
Issue |
1 |
Pages |
48-52 |
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Keywords |
Age Factors; Animals; *Feeding Behavior; Female; *Intelligence; Male; *Motor Skills; *Nuts; *Parrots |
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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. |
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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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1435-9448 |
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PMID:15248094 |
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no |
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Call Number |
Equine Behaviour @ team @ |
Serial |
2518 |
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Author |
Milgram, N.W.; Head, E.; Muggenburg, B.; Holowachuk, D.; Murphey, H.; Estrada, J.; Ikeda-Douglas, C.J.; Zicker, S.C.; Cotman, C.W. |
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Title |
Landmark discrimination learning in the dog: effects of age, an antioxidant fortified food, and cognitive strategy |
Type |
Journal Article |
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Year |
2002 |
Publication |
Neuroscience and Biobehavioral Reviews |
Abbreviated Journal |
Neurosci Biobehav Rev |
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Volume |
26 |
Issue |
6 |
Pages |
679-695 |
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Keywords |
Age Factors; Aging/*physiology; Analysis of Variance; Animals; Antioxidants/*pharmacology; Blood Chemical Analysis/methods; Cognition/*physiology; *Diet; Discrimination Learning/*drug effects/*physiology; Distance Perception/drug effects/physiology; Dogs/physiology; Female; Male; Psychomotor Performance/physiology; Retention (Psychology)/drug effects/physiology; Spatial Behavior/*drug effects/*physiology; Task Performance and Analysis; Time Factors; Vitamin E/blood |
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Abstract |
The landmark discrimination learning test can be used to assess the ability to utilize allocentric spatial information to locate targets. The present experiments examined the role of various factors on performance of a landmark discrimination learning task in beagle dogs. Experiments 1 and 2 looked at the effects of age and food composition. Experiments 3 and 4 were aimed at characterizing the cognitive strategies used in performance on this task and in long-term retention. Cognitively equivalent groups of old and young dogs were placed into either a test group maintained on food enriched with a broad-spectrum of antioxidants and mitochondrial cofactors, or a control group maintained on a complete and balanced food formulated for adult dogs. Following a wash-in period, the dogs were tested on a series of problems, in which reward was obtained when the animal responded selectively to the object closest to a thin wooden block, which served as a landmark. In Experiment 1, dogs were first trained to respond to a landmark placed directly on top of coaster, landmark 0 (L0). In the next phase of testing, the landmark was moved at successively greater distances (1, 4 or 10 cm) away from the reward object. Learning varied as a function of age group, food group, and task. The young dogs learned all of the tasks more quickly than the old dogs. The aged dogs on the enriched food learned L0 significantly more rapidly than aged dogs on control food. A higher proportion of dogs on the enriched food learned the task, when the distance was increased to 1cm. Experiment 2 showed that accuracy decreased with increased distance between the reward object and landmark, and this effect was greater in old animals. Experiment 3 showed stability of performance, despite using a novel landmark, and new locations, indicating that dogs learned the landmark concept. Experiment 4 found age impaired long-term retention of the landmark task. These results indicate that allocentric spatial learning is impaired in an age-dependent manner in dogs, and that age also affects performance when the distance between the landmark and target is increased. In addition, these results both support a role of oxidative damage in the development of age-associated cognitive dysfunction and indicate that short-term administration of a food enriched with supplemental antioxidants and mitochondrial cofactors can partially reverse the deleterious effects of aging on cognition. |
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Address |
Life Science Division, University of Toronto at Scarborough, 1265 Military Trail, Scarborough, Ont., Canada M1C 1A4. milgram@psych.utoronto.ca |
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0149-7634 |
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PMID:12479842 |
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Call Number |
Equine Behaviour @ team @ |
Serial |
2806 |
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Author |
Cameron, E.Z. |
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Title |
Facultative adjustment of mammalian sex ratios in support of the Trivers-Willard hypothesis: evidence for a mechanism |
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Journal Article |
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Year |
2004 |
Publication |
Proceedings. Biological sciences / The Royal Society |
Abbreviated Journal |
Proc Biol Sci |
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Volume |
271 |
Issue |
1549 |
Pages |
1723-1728 |
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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 |
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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. |
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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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0962-8452 |
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PMID:15306293 |
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refbase @ user @ |
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413 |
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Author |
Liebal, K.; Pika, S.; Tomasello, M. |
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Title |
Social communication in siamangs (Symphalangus syndactylus): use of gestures and facial expressions |
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Journal Article |
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Year |
2004 |
Publication |
Primates |
Abbreviated Journal |
Primates |
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Volume |
45 |
Issue |
1 |
Pages |
41-57 |
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Keywords |
Age Factors; *Animal Communication; Animals; Animals, Zoo/*physiology; *Cognition; Female; Hylobates/*physiology; *Kinesics; Male; Sex Factors; *Social Behavior; Video Recording |
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Abstract |
The current study represents the first systematic investigation of the social communication of captive siamangs (Symphalangus syndactylus). The focus was on intentional signals, including tactile and visual gestures, as well as facial expressions and actions. Fourteen individuals from different groups were observed and the signals used by individuals were recorded. Thirty-one different signals, consisting of 12 tactile gestures, 8 visual gestures, 7 actions, and 4 facial expressions, were observed, with tactile gestures and facial expressions appearing most frequently. The range of the signal repertoire increased steadily until the age of six, but declined afterwards in adults. The proportions of the different signal categories used within communicative interactions, in particular actions and facial expressions, also varied depending on age. Group differences could be traced back mainly to social factors or housing conditions. Differences in the repertoire of males and females were most obvious in the sexual context. Overall, most signals were used flexibly, with the majority performed in three or more social contexts and almost one-third of signals used in combination with other signals. Siamangs also adjusted their signals appropriately for the recipient, for example, using visual signals most often when the recipient was already attending (audience effects). These observations are discussed in the context of siamang ecology, social structure, and cognition. |
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Address |
Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany. liebal@eva.mpg.de |
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0032-8332 |
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PMID:14655035 |
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no |
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Call Number |
Equine Behaviour @ team @ |
Serial |
2812 |
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Author |
Call, J. |
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Title |
Inferences by exclusion in the great apes: the effect of age and species |
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Journal Article |
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Year |
2006 |
Publication |
Animal Cognition |
Abbreviated Journal |
Anim. Cogn. |
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Volume |
9 |
Issue |
4 |
Pages |
393-403 |
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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 |
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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. |
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Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103, Leipzig, Germany. call@eva.mpg.de |
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English |
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1435-9448 |
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PMID:16924458 |
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Equine Behaviour @ team @ |
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2444 |
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