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| Author | Pluhácek,j.; Bartos,L.; Víchová,J. | ||||
Title  |
Variation In Incidence Of Male Infanticide Within Subspecies Of Plains Zebra (Equus Burchelli) | Type | Journal Article | ||
| Year | 2006 | Publication | Journal of Mammalogy | Abbreviated Journal | |
| Volume | 87 | Issue | 1 | Pages | 35-40 |
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| Abstract | Social organization seems to determine the occurrence of male infanticide in equids. Although, no information concerning social organization of the maneless zebra (Equus burchelli borensis) has been available, we presumed that the occurrence of infanticide would be the same across all subspecies of plains zebra. We examined the occurrence of this phenomenon in 9 herds of 4 subspecies: the maneless zebra, Grant's zebra (E. burchelli boehmi), Chapmann's zebra (E. b. chapmanni), and the Damara zebra (E. b. antiquorum) at 4 zoos. The probability of a foal's death was affected by the presence of a new male and subspecies. Except for the maneless zebra, all subspecies showed existence of male infanticide. We found no occurrence of male infanticide in maneless zebras, which suggests a different social system. This would also support the subspecific status of the maneless zebra. | ||||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 2212 | ||
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| Author | Santamaria, S.; Bobbert, M.E.; Back, W.; Barneveld, A.; van Weeren, P.R. | ||||
| Title |
Variation in free jumping technique within and among horses with little experience in show jumping | Type | Journal Article | ||
| Year | 2004 | Publication | American Journal of Veterinary Research | Abbreviated Journal | Am J Vet Res |
| Volume | 65 | Issue | 7 | Pages | 938-944 |
| Keywords | *Acceleration; Analysis of Variance; Animals; Biomechanics; Forelimb/physiology; Gait/*physiology; Hindlimb/physiology; Horses/*physiology; Locomotion/*physiology; Models, Biological; Video Recording | ||||
| Abstract | OBJECTIVE: To quantify variation in the jumping technique within and among young horses with little jumping experience, establish relationships between kinetic and kinematic variables, and identify a limited set of variables characteristic for detecting differences in jumping performance among horses. ANIMALS: Fifteen 4-year-old Dutch Warmblood horses. PROCEDURE: The horses were raised under standardized conditions and trained in accordance with a fixed protocol for a short period. Subsequently, horses were analyzed kinematically during free jumping over a fence with a height of 1.05 m. RESULTS: Within-horse variation in all variables that quantified jumping technique was smaller than variation among horses. However, some horses had less variation than others. Height of the center of gravity (CG) at the apex of the jump ranged from 1.80 to 2.01 m among horses; this variation could be explained by the variation in vertical velocity of the CG at takeoff (r, 0.78). Horses that had higher vertical velocity at takeoff left the ground and landed again farther from the fence, had shorter push-off phases for the forelimbs and hind limbs, and generated greater vertical acceleration of the CG primarily during the hind limb push-off. However, all horses cleared the fence successfully, independent of jumping technique. CONCLUSIONS AND CLINICAL RELEVANCE: Each horse had its own jumping technique. Differences among techniques were characterized by variations in the vertical velocity of the CG at takeoff. It must be determined whether jumping performance later in life can be predicted from observing free jumps of young horses. | ||||
| Address | Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 12, NL-3584 CM Utrecht, The Netherlands | ||||
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| Language | English | Summary Language | Original Title | ||
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| ISSN | 0002-9645 | ISBN | Medium | ||
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| Notes | PMID:15281652 | Approved | no | ||
| Call Number | Equine Behaviour @ team @ | Serial | 3772 | ||
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| Author | Holmstrom, M.; Magnusson, L.E.; Philipsson, J. | ||||
| Title |
Variation in conformation of Swedish warmblood horses and conformational characteristics of elite sport horses | Type | Journal Article | ||
| Year | 1990 | Publication | Equine Veterinary Journal | Abbreviated Journal | Equine Vet J |
| Volume | 22 | Issue | 3 | Pages | 186-193 |
| Keywords | Age Factors; Analysis of Variance; Animals; *Breeding; Female; Forelimb/anatomy & histology; Hindlimb/anatomy & histology; Horses/*anatomy & histology/physiology; Least-Squares Analysis; Male; Physical Conditioning, Animal; Regression Analysis; Sex Characteristics | ||||
| Abstract | The variation in conformation of 356 Swedish Warmblood horses is described, using a quantitative method of measuring horses. Thirty-three of the horses were elite dressage horses, 28 were elite showjumpers, 100 were riding school horses and 195 were unselected four-year-olds. Most horses had a long body form. The average height at the withers was 163.4 cm. Sixty per cent of the horses had a bench knee conformation, 50 per cent had a toe-in conformation of the forelimbs and 80 per cent had outwardly rotated hind limbs. The majority of these deviations were mild or moderate. Conformation was influenced by sex and age. Mares were smaller and had longer bodies and shorter limbs. The elite dressage horses and showjumpers had larger hock angles and more sloping scapulas than other horses. The showjumpers also had smaller fetlock angles in the front limbs. It is suggested that the larger hock angles among the elite horses may be because hocks with small angles are more prone to injury, and because small hock angles may negatively influence the ability to attain the degree of collection necessary for good performance in advanced classes. | ||||
| Address | Department of Animal Hygiene, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Skara | ||||
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| Language | English | Summary Language | Original Title | ||
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| ISSN | 0425-1644 | ISBN | Medium | ||
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| Notes | PMID:2361507 | Approved | no | ||
| Call Number | Equine Behaviour @ team @ | Serial | 3756 | ||
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| Author | Normando, S.; Meers, L.; Samuels, W.E.; Faustini, M.; Ödberg, F.O. | ||||
| Title |
Variables affecting the prevalence of behavioural problems in horses. Can riding style and other management factors be significant? | Type | Journal Article | ||
| Year | 2011 | Publication | Applied Animal Behaviour Science | Abbreviated Journal | Appl. Anim. Behav. Sci. |
| Volume | 133 | Issue | 3-4 | Pages | 186-198 |
| Keywords | Horse; Management; Problem behaviour; Riding style; Saddle; Stereotypies | ||||
| Abstract | The effects of riding style and various management factors on the prevalence of stereotypies and other behavioural problems among 346 mixed-breed saddle horses (phase 1) and 101 Arabian horses (phase 2) were analysed through a questionnaire answered by owners. In phase 1, the questionnaire data were partially validated through 20-min observations of 81 (23.3%) of the cases. Results indicate that horses primarily ridden in the English style were reported to be significantly more likely to display stereotypies (p < 0.001), problems when transported (p = 0.001), multiple behavioural problems (p < 0.001), and to have more restrictive stabling (p < 0.001) than horses ridden with other styles. When only Arabian horses were assessed in phase 2, however, there was no significant difference in behavioural problems between the Arabian horses ridden English style versus other riding styles. However Arabian horses were housed less restrictively than horses in phase 1 and English riding style and restrictive stabling tended to exacerbate each other's association with stereotypies. Management-related effects were found when, e.g., horses housed in restrictive stabling were more frequently reported to show locomotion stereotypies (p = 0.02) and those denied ad libitum hay displayed stereotypic wood-chewing behaviour (p = 0.02). To aid diagnosing and prioritizing interventions and care, the most predictive subsets of factors were computed for the various problem behaviours. E.g., among saddle horses, a statistical model comprised of the main riding style, duration of access to a paddock, and horse's age predicted whether a horse was reported to display any behavioural problem 62% of the time. This study supports the effects of management and handling on the prevalence of behavioural problems, and helps prioritize the relative importance of broad management categories on equine welfare. In particular, it underscores the importance of riding style on the well-being of saddle horses. | ||||
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| ISSN | 0168-1591 | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 5399 | ||
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| Author | Digweed, Shannon M.; Fedigan, Linda M.; Rendall, Drew | ||||
| Title |
Variable specificity in the anti-predator vocalizations and behaviour of the white-faced capuchin, Cebus capucinus | Type | Journal Article | ||
| Year | 2005 | Publication | Behaviour | Abbreviated Journal | Behaviour |
| Volume | 142 | Issue | 8 | Pages | 997-1021 |
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| Abstract | (Accepted: 23 June 2005) Summary Much research in animal communication is aimed at understanding the functional design features of animal vocal signals. Our detailed analyses of the vocalizations and behavioural responses elicited in white-faced capuchins by predators and other disturbances point to two call variants that differ modestly in their acoustic structure and that are accompanied by functionally distinct behavioural responses. The first variant is given exclusively to avian predators and is almost invariably accompanied by the monkeys immediate descent from the treetops where it is most vulnerable; therefore, we label this call variant the aerial predator alarm?. The second variant, that differs only slightly but noticeably from the first, is given to a wide range of snakes and mammals, including a range of species that represent no predatory threat to the monkeys. This second call is also associated with more variable responses from calling monkeys, from delayed retreat from the source of disturbance, to active approach, inspection, and sometimes mobbing of the animal involved. We therefore label this variant more generally as an “alerting call”. Although some other primate species show a more diverse system of anti-predator calls, and the capuchins themselves may yet be found to produce a greater variety of calls, a system of two call variants with varying degrees of predator specificity and behavioural response is not uncommon among primates and appears functionally appropriate for capuchins. The basic structure of the alerting call allows conspecific listeners to localize the caller and the source of disturbance readily, thereby allowing listeners to approach and assist in mobbing in cases where the disturbance warrants it, or to avoid the area in cases where the disturbance is identified as a predatory threat. Conversely, the aerial predator alarm is inherently less localizable and therefore conveys the |
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| Notes | Approved | no | |||
| Call Number | refbase @ user @ | Serial | 547 | ||
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| Author | Lamprecht, J. | ||||
| Title |
Variable Leadership in Bar-Headed Geese (Anser Indicus) : an Analysis of Pair and Family Departures | Type | Journal Article | ||
| Year | 1992 | Publication | Behaviour | Abbreviated Journal | Behaviour |
| Volume | 122 | Issue | 1-2 | Pages | 105-119 |
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| Abstract | This paper reports quantitative leadership differences in semi-captive bar-headed geese (Anser indicus) at different times of the year, and in different types of groups. Leading is defined here as causing the departure or determining the direction of movement of the whole group. No permanent and exclusive leader of a pair or family group was found, rather relative leading frequencies of male, female and young showed a definite shifting pattern. Females led more often than their mates prior to breeding, and on nest pauses during the incubation period, but less often in summer, autumn and early winter. In families there was no difference between the frequencies of male and female leading. Family females led relatively more often than those of pairs without offspring. This difference was related to the presence, not the number, of young. Goslings led the family about as often as the parents during the rearing period in early summer, less often in autumn, winter and next spring. Such differences and changes are to be expected where competence in particular tasks and dependence on partners vary between group members, and where different situations require different abilities. For the geese, the results can be related to the different options of group members and to the different benefits they derive from leaving (or 'staying put') or following (or waiting for the others) in different situations. | ||||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 5128 | ||
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| Author | Potts, R. | ||||
| Title |
Variability selection in hominid evolution | Type | Journal Article | ||
| Year | 1998 | Publication | Evolutionary Anthropology: Issues, News, and Reviews | Abbreviated Journal | Evol. Anthropol. |
| Volume | 7 | Issue | 3 | Pages | 81-96 |
| Keywords | variability selection; hominids; environment; adaptation; natural selection; evolution | ||||
| Abstract | Variability selection (abbreviated as VS) is a process considered to link adaptive change to large degrees of environment variability. Its application to hominid evolution is based, in part, on the pronounced rise in environmental remodeling that took place over the past several million years. The VS hypothesis differs from prior views of hominid evolution, which stress the consistent selective effects associated with specific habitats or directional trends (e.g., woodland, savanna expansion, cooling). According to the VS hypothesis, wide fluctuations over time created a growing disparity in adaptive conditions. Inconsistency in selection eventually caused habitat-specific adaptations to be replaced by structures and behaviors responsive to complex environmental change. Key hominid adaptations, in fact, emerged during times of heightened variability. Early bipedality, encephalized brains, and complex human sociality appear to signify a sequence of VS adaptations—i.e., a ratcheting up of versatility and responsiveness to novel environments experienced over the past 6 million years. The adaptive results of VS cannot be extrapolated from selection within a single environmental shift or relatively stable habitat. If some complex traits indeed require disparities in adaptive setting (and relative fitness) in order to evolve, the VS idea counters the prevailing view that adaptive change necessitates long-term, directional consistency in selection. © 1998 Wiley-Liss, Inc. | ||||
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| Publisher | John Wiley & Sons, Inc. | Place of Publication | Editor | ||
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| ISSN | 1520-6505 | ISBN | Medium | ||
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| Notes | Approved | no | |||
| Call Number | Equine Behaviour @ team @ | Serial | 5461 | ||
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| Author | Godin, J.-G.J.; Dugatkin, L.A. | ||||
| Title |
Variability and repeatability of female mating preference in the guppy | Type | Journal Article | ||
| Year | 1995 | Publication | Animal Behaviour. | Abbreviated Journal | Anim. Behav. |
| Volume | 49 | Issue | 6 | Pages | 1427-1433 |
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| Abstract | Models of inter-sexual selection generally assume heritable variation in mating preferences among females within populations. However, little is known about the nature of such variation. The aim of this study was to characterize quantitatively the phenotypic variation in female preference for a sexually selected male trait, body colour pattern, within a population of the Trinidadian guppy, Poecilia reticulata. Significantly more female guppies preferred the more brightly coloured of two similar-sized males presented simultaneously as potential mates. Mating preference scores for individual females were significantly and positively correlated between two repeated trials on successive days. Females were thus individually consistent in their particular choice of mates, and the calculated repeatability of their mating preference was relatively high. Notwithstanding the aforementioned, significant variation existed among females in the degree of their preference for brightly coloured males. Individual mating preference scores were not normally distributed, but were rather skewed to the right (i.e. towards greater values). These results suggest that additive genetic variation for mating preferences based on male colour pattern is maintained, and the opportunity for the further evolution of both bright male colour patterns and female preference for this trait appears to exist in the study population from the Quare River, Trinidad. | ||||
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| Notes | Approved | no | |||
| Call Number | refbase @ user @ | Serial | 492 | ||
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| Author | Zentall, T.R.; Sherburne, L.M.; Roper, K.L.; Kraemer, P.J. | ||||
| Title |
Value transfer in a simultaneous discrimination appears to result from within-event pavlovian conditioning | Type | Journal Article | ||
| Year | 1996 | Publication | Journal of experimental psychology. Animal behavior processes | Abbreviated Journal | J Exp Psychol Anim Behav Process |
| Volume | 22 | Issue | 1 | Pages | 68-75 |
| Keywords | Animals; Behavior, Animal; Columbidae; *Conditioning, Classical; *Discrimination Learning; Female; Male; *Reinforcement (Psychology) | ||||
| Abstract | When pigeons acquire a simple simultaneous discrimination, some of the value acquired by the S+ transfers to the S-. The mechanism underlying this transfer of value was examined in three experiments. In Experiment 1, pigeons trained on two simultaneous discriminations (A + B- and C +/- D-) showed a preference for B over D. This preference was reduced, however, following the devaluation of A. In Experiment 2, when after the same original training, value was given to D, the pigeons' preference for C did not significantly increase. In Experiment 3, when both discriminations involved partial reinforcement (S +/-), A + C- training resulted in a preference for B over D, whereas B + D- training resulted in a preference for A over C. Thus, simultaneous discrimination training appears to result in bidirectional within-event conditioning involving the S+ and S-. | ||||
| Address | Department of Psychology, University of Kentucky Lexington 40506, USA | ||||
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| ISSN | 0097-7403 | ISBN | Medium | ||
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| Notes | PMID:8568497 | Approved | no | ||
| Call Number | refbase @ user @ | Serial | 255 | ||
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| Author | Pichardo, M. | ||||
| Title |
Valsequillo biostratigraphy. III: Equid ecospecies in Paleoindian sites | Type | Journal Article | ||
| Year | 2000 | Publication | Anthropologischer Anzeiger; Bericht Uber die Biologisch-Anthropologische Literatur | Abbreviated Journal | Anthropol Anz |
| Volume | 58 | Issue | 3 | Pages | 275-298 |
| Keywords | Animals; *Ecology; Horses/*classification; Mexico; *Paleodontology; Species Specificity | ||||
| Abstract | Greater precision in North American Pleistocene equid taxonomy makes it now possible to exploit the ubiquitous horse remains in Paleoindian sites as ecological index-fossils. The horses of Central Mexico and the Southern Plains can be sorted by tooth size alone, except for two rare large horses of the Southern Plains. The species endemic to these grasslands and south to Central Mexico are Equus pacificus (large), E. conversidens (small), E. francisci (smallest). The Southern Plains were also occupied by a specialized grazer E. excelsus (Burnet and Sandia caves) and E. occidentalis (Dry and Sandia caves). West of the Rocky Mountains E. occidentalis was dominant. East of the Mississippi River two woodland species are found: E. fraternus and E. littoralis. | ||||
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| ISSN | 0003-5548 | ISBN | Medium | ||
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| Notes | PMID:11082786 | Approved | no | ||
| Call Number | Equine Behaviour @ team @ | Serial | 2648 | ||
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