| Home | [11–20] << 21 22 23 24 25 26 27 28 29 30 >> [31–40] |
|
Visser, E. K., Van Reenen, C. G., Engel, B., Schilder, M. B. H., Barneveld, A., & Blokhuis, H. J. (2003). The association between performance in show-jumping and personality traits earlier in life. Appl. Anim. Behav. Sci., 82(4), 279–295.
Abstract: For a horse to succeed in a show-jumping career, the individual has to possess both excellent physical abilities as well as a suitable personality to perform under challenging conditions. Forty-one Dutch Warmblood horses were used to develop personality tests and correlations between test variables and early training performances in jumping were studied. In behavioural tests, during the first 2 years of the horses' lives, personality aspects like emotionality, reactivity to human and learning abilities were quantified. At the age of 3, horses were broken and received early training in show-jumping. The inter-relationship between several performance variables measured during this early training phase were studied using principal component analysis (PCA). Variables measured in the different personality tests (novel-object test, handling test, avoidance-learning test and a reward-learning test) showed no correlations, suggesting that these tests all triggered different aspects of a horse's personality. This study indicates that it is possible to predict a substantial part of the show-jumping performance of an individual horse later in life by personality traits earlier in life.
Keywords: Personality; Performance; Horses; Prediction; Individual differences; Behavioural tests
|
|
Schwarzenberger, F., Mostl, E., Palme, R., & Bamberg, E. (1996). Faecal steroid analysis for non-invasive monitoring of reproductive status in farm, wild and zoo animals. Animal Reproduction: Research and Practice, 42(1-4), 515–526.
Abstract: Non-invasive faecal oestrogen and progesterone metabolite evaluations are well established approaches for monitoring reproductive function in a variety of mammalian species. The route of excretion of steroid hormone metabolites varies considerably among species, and also between steroids within the same species. Steroid concentrations in faeces exhibit a similar pattern to those in plasma, but have a lag time, which depending upon the species, can be from 12 h to more than 2 days. Faecal steroid metabolites in mammals are mainly unconjugated compounds. Faecal oestrogens consist predominantly of oestrone and/or oestradiol-17α or -17β. Therefore, specific oestrogen antibodies or antibodies against total oestrogens can be used for their determination. Progesterone is metabolised to several 5α- or 5β-reduced pregnanediones and hydroxylated pregnanes prior to its faecal excretion. Therefore, relevant antibodies for their determination show considerable cross-reactivities with several pregnane metabolites, whereas specific progesterone antibodies are less suitable. Faecal oestrogen evaluations have been used as reliable indicators of pregnancy in several ungulate and some primate species. They have also been used to determine the preovulatory period in carnivores, corpus luteum activity in New World primates, and to diagnose cryptorchidism in horses. Faecal progesterone metabolite analysis has been successfully used for monitoring corpus luteum function and pregnancy, abortion, seasonality and treatment therapies in an ever expanding list of species.
|
|
Hausberger, M., & Muller, C. (2002). A brief note on some possible factors involved in the reactions of horses to humans. Appl. Anim. Behav. Sci., 76(4), 339–344.
Abstract: In order to investigate relationships of adult horses to humans, we developed a simple evaluation test and scores based on observations. The first reactions of 224 adult horses to the presence of an experimenter were observed and scored. All these horses belonged to the same riding school, had the same general housing conditions and were all geldings. The evaluation was based on the horse's posture. Individual differences that could be related to some extent to the breed but also to human factors emerged clearly. French saddlebreds showed more often friendly behaviour than Angloarabs, whereas thoroughbreds were more indifferent. Clear variations occurred between groups of horses that depended on different caretakers. In this school, one caretaker is responsible for the whole daily management of a group of horses and is probably a very important factor in their well-being. The effects of this daily relation to a human seemed to be involved in the reactions to a strange person. Further studies are required to investigate what, in practice, may be determinant.
|
|
Henry, S., Hemery, D., Richard, M. - A., & Hausberger, M. (2005). Human-mare relationships and behaviour of foals toward humans. Appl. Anim. Behav. Sci., 93(3-4), 341–362.
Abstract: We studied experimentally whether horse dams influenced foals' relationships with humans. We investigated the influence of the establishment of positive human-mare relationships on foals' behaviour toward humans. Forty-one foals and their dams were involved in this experiment. Half of the mares were softly brushed and fed by hand during a short period (total of 1.25 h) during the first 5 days of their foals' lives (experimental group, n = 21). The other mares were not handled experimentally and their foals received no contact with the experimenter (control group, n = 20). The reactions of both experimental and control foals were recorded under various conditions, first, for 5 min in the presence of a motionless experimenter, when foals were 15 and 30-35 days old, then in an approach test when they were 15 days old and in a saddle-pad tolerance test when they were 30-35 days old. Finally, approach-stroking tests were performed successively by the familiar experimenter when foals were 11-13 months old and by an unfamiliar person when they were 13-15 months old. Several observations strongly suggest that mares can influence their foals' behaviour toward humans: (1) during the handling procedure, experimental foals of protective mares were further from the handler than foals of calm mares (p < 0.001); (2) experimental foals remained, at all ages, closer to the experimenter (p < 0.05) and initiated more physical contacts (sniffing, licking, etc.) with the experimenter (p < 0.05) than control foals; (3) avoidance and flight responses of experimental foals were considerably reduced during approaches by the experimenter (p < 0.01) and they accepted saddle-pads on their backs more easily (p < 0.01) and more quickly (p < 0.01) than control foals. Lastly, the consequences of handling mares had effects that lasted at least until foals were one year old (p < 0.05) and became generalized from experimenter to unfamiliar humans, who could approach and stroke experimental foals rapidly during a test (p < 0.05). This is the first report of an attempt to use observation of mother by foals to facilitate human-foal relationships. The procedure is simple, takes little time and can easily be applied to any dam-foal pair, as it is not intrusive and presents no risks of disrupting mare-foal bonds.
|
|
Thorne, J. B., Goodwin, D., Kennedy, M. J., Davidson, H. P. B., & Harris, P. (2005). Foraging enrichment for individually housed horses: Practicality and effects on behaviour. Appl. Anim. Behav. Sci., 94(1-2), 149–164.
Abstract: The stabled (UK) or stalled (USA) horse is commonly fed a restricted-forage diet in contrast to the varied ad libitum high-fibre diet it evolved to consume. A low-forage diet has been linked to the performance of stereotypical behaviour and health problems including gastric ulceration and impaction colic (in cases where horses are bedded on straw). Provision of a diet closer to that which the horse is adapted to and which enables more natural feeding behaviour warrants investigation. This trial aimed to establish whether the behavioural effects observed in short-term trials when stabled horses were provided with a multiple forage diet persist over longer periods. It also aimed to develop a practical methodology for maintaining stabled horses under forage-enriched conditions. Nine horses (aged 5-20 years, various breeds), acting as their own controls, participated in an 18-day, cross-over, Latin Square designed trial, in which they received comparable weights of two dietary treatments: a Single Forage (SF, hay) diet and a Multiple Forage (MF) diet (three long-chop and three short-chop commercially available forages). Following a 2-day acclimatisation, horses were maintained on the forage treatments for 7 days. Horses were observed on alternate days, morning and afternoon, during the 25 min following forage presentation. Horses then crossed over onto their second treatment and, following a further 2 days' acclimatisation, the same protocol was followed for a further 7 days. Observations from video were made using The Observer 3.0(R) and SPPS (version 11). Horses on the MF treatment performed foraging behaviour significantly more frequently and for significantly longer periods than horses on the SF treatment. On the MF treatment horses sampled all forages during observations. However, there were significant differences in the frequency and duration of foraging on individual forages, indicating that horses demonstrated individual preferences for particular forages. Stereotypic weaving behaviour only occurred on the SF treatment. The results indicate that the potentially beneficial behavioural effects of short-term multiple forage provision do persist when horses are managed on a MF diet for a 7-day period. They suggest that a MF diet provides a means of enriching the stabled horse's environment, by offering variety and enabling patch foraging behaviour. The methodology proved practical for maintaining horses under forage-enriched conditions and could easily be adopted by horse owners to facilitate foraging behaviour.
Keywords: Horse; Foraging behaviour; Eating; Feeding; Enrichment; Welfare
|
|
King, S. R. B., & Gurnell, J. (2005). Habitat use and spatial dynamics of takhi introduced to Hustai National Park, Mongolia. Biol. Conserva., 124(2), 277–290.
Abstract: The successful introduction of captive bred takhi or Przewalski's horse, Equus ferus przewalskii, into Mongolia in the 1990s is a good example of the benefits of ex situ conservation and one of the few examples of the recovery of an animal after it became extinct in the wild. This is also particularly interesting because virtually nothing was known about how takhi lived before they died out, and the introductions have enabled us to study how they have settled, and their ecology and behaviour within their former natural range. In this paper, we describe the movement, home range size and shape, and habitat use of takhi at one of the release areas, the 570 km2 Hustai National Park in Mongolia. Harem home ranges varied between 129 and 2399 ha, with 80% core areas of between 61 and 1196 ha. There was no relationship between range size and harem size, or length of time since release. Initially, harems stayed near their release enclosures, but over time they established home ranges further away. There was little overlap between home ranges of different harems, but neither was there evidence of exclusive range use. The more nutritious vegetation at lower elevations was preferentially selected. Thus the present situation looks good, but, as the population continues to grow, we anticipate that there will be potential problems related to intraspecific competition for water and vegetation resources, and the potential for hybridisation with domestic horses belonging to the local people. We consider the time it may take for takhi to reach carrying capacity within Hustai National Park and emphasise that continual monitoring of the population is essential because interventional management is likely to be required in the future.
Keywords: Home range; Habitat use; Equus przewalskii; Takhi; Reintroduction
|
|
Clotfelter, E. D., & Paolino, A. D. (2003). Bystanders to contests between conspecifics are primed for increased aggression in male fighting fish. Anim. Behav., 66(2), 343–347.
Abstract: We performed two experiments in which we allowed a male fighting fish, Betta splendens, designated a bystander, to observe aggressive contests between pairs of male conspecifics. Another male (naive male) observed an empty tank or two nonaggressive males, depending on the experiment. Immediately after these observation periods, we allowed the bystander and naive male to interact in a neutral area. In both experiments, bystander males were dominant over naive males in a significant number of the encounters. Bystander males performed significantly more aggressive behaviours (displays, chases and bites) than did naive males. Differences in dominance were not due to chance differences in body size. These findings demonstrate that exposure to aggression between conspecifics increases aggressive motivation in bystander male fighting fish. We discuss briefly the implications of such social experience on the formation of dominance hierarchies. Copyright 2003 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.
|
|
Agrillo, C., Dadda, M., & Bisazza, A. (2007). Quantity discrimination in female mosquitofish. Anim. Cogn., 10(1), 63–70.
Abstract: The ability in animals to count and represent different numbers of objects has received a great deal of attention in the past few decades. Cumulative evidence from comparative studies on number discriminations report obvious analogies among human babies, non-human primates and birds and are consistent with the hypothesis of two distinct and widespread mechanisms, one for counting small numbers (<4) precisely, and one for quantifying large numbers approximately. We investigated the ability to discriminate among different numerosities, in a distantly related species, the mosquitofish, by using the spontaneous choice of a gravid female to join large groups of females as protection from a sexually harassing male. In one experiment, we found that females were able to discriminate between two shoals with a 1:2 numerosity ratio (2 vs. 4, 4 vs. 8 and 8 vs. 16 fish) but failed to discriminate a 2:3 ratio (8 vs. 12 fish). In the second experiment, we studied the ability to discriminate between shoals that differed by one element; females were able to select the larger shoal when the paired numbers were 2 vs. 3 or 3 vs. 4 but not 4 vs. 5 or 5 vs. 6. Our study indicates that numerical abilities in fish are comparable with those of other non-verbal creatures studied; results are in agreement with the hypothesis of the existence of two distinct systems for quantity discrimination in vertebrates.
|
|
Gardner, A., West, S. A. (2004). Cooperation and Punishment, Especially in Humans. Americ. Natur., 164(6), 753–764.
Abstract: Explaining altruistic cooperation is one of the greatest
challenges faced by sociologists, economists, and evolutionary biologists. The problem is determining why an individual would carry out a costly behavior that benefits another. Possible solutions to this problem include kinship, repeated interactions, and policing. Another solution that has recently received much attention is the threat of punishment. However, punishing behavior is often costly for the punisher, and so it is not immediately clear how costly punishment could evolve. We use a direct (neighbor-modulated) fitness approach to analyze when punishment is favored. This methodology reveals that, contrary to previous suggestions, relatedness between interacting individuals is not crucial to explaining cooperation through punishment. In fact, increasing relatedness directly disfavors punishing behavior. Instead, the crucial factor is a positive correlation between the punishment strategy of an individual and the cooperation it receives. This could arise in several ways, such as when facultative adjustment of behavior leads individuals to cooperate more when interacting with individuals who are more likely to punish. More generally, our results provide a clear example of how the fundamental factor driving the evolution of social traits is a correlation between social partners and how this can arise for reasons other than genealogical kinship. |
|
Wittig, R. M., Crockford, C., Wikberg, E., Seyfarth, R. M., & Cheney, D. L. (2007). Kin-mediated reconciliation substitutes for direct reconciliation in female baboons. Proc Biol Sci, 274(1613), 1109–1115.
Abstract: It has been hypothesized that group-living mammals engage in reconciliation (post-conflict affiliation between former opponents) to reduce the disruptive costs of aggression and restore opponents' tolerance to baseline levels. Recipients of aggression are sometimes reluctant to tolerate the proximity of a recent opponent, however, in apparent fear that aggression will be renewed. In such cases, reconciliatory behaviour by the aggressor's close kin may substitute for direct reconciliation. We describe a playback experiment with free-ranging baboons (Papio hamadryas ursinus) that examines whether friendly behaviour by the aggressor's kin can substitute for direct reconciliation by the aggressor herself. In the test condition, female subjects who had recently been threatened heard the friendly grunt of one of their aggressor's relatives, mimicking kin-mediated vocal reconciliation. In the control condition, subjects heard the grunt of a dominant female from a different matriline. Subjects responded significantly more strongly in test than in control trials. Moreover, in the next hour they were significantly more likely to tolerate the proximity of both their aggressor and the relative whose grunt they had heard. In contrast, subjects' behaviour towards both control females and other members of their aggressor's matriline was unaffected. We conclude that kin-mediated vocal reconciliation can substitute for direct reconciliation in baboons.
|