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Desire L., Boissy A., & Veissier I. (2002). Emotions in farm animals: – a new approach to animal welfare in applied ethology. Behav. Process., 60, 165–180.
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Davies Morel, M. C. G., Newcombe, J. R., & Holland, S. J. (2002). Factors affecting gestation length in the Thoroughbred mare. Animal Reproduction Science, 74(3-4), 175–185.
Abstract: In order to assist in the accurate prediction of the timing of parturition in the mare true gestation length, along with the potential effect of a number of factors, was investigated. Data from 433 Thoroughbred foal pregnancies were used. Sequential ultrasonic scanning allowed the true gestation length (fertilisation-parturition) to be ascertained, as apposed to previous work, which used the mating-parturition interval. An average gestation length of 344.1+/-0.49 days was evident. Colt foal pregnancies were significantly (P<0.001) longer (346.2+/-0.72) than fillies (342.4+/-0.65). Month of birth had a significant effect on gestation length in all foals (P<0.001). With foals born in January having the shortest gestation lengths and those born in April the longest. Mare age, year of birth, stallion age, stud farm and the interval between ovulation and mating had no significant effect. It is concluded that (i) the gestation length range (315-388 days), all resulting in viable foals is noteworthy and of clinical importance when considering the classification of dysmaturity in foals, (ii) mares carrying colt foals due to be born in the middle of the breeding season (April) are likely to have the longer gestation lengths.
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Davidson, N., & Harris, P. (2002). Nutrition and Welfare. In The Welfare of Horses (pp. 45–76).
Abstract: The horse is a social species living in herds and spending the majority of its time roaming and foraging in a diverse and seasonally-varying environment. As a non-ruminant herbivore it is well suited to a high fibre, low starch diet. Domestication has resulted in a number of benefits to the horse, reflected in its continued prevalence and apparently increased life expectancy, but it has not been without its price. Especially in developed countries, horses kept for leisure purposes (which includes all competition and racing horses) are often confined, possibly away from conspecifics, within a stable for a large proportion of the day. Due to increased energy requirements many horses now receive one to two large meals a day, consisting of feedstuffs with a low water content and often a radically different nutritional profile from the diet that they would be able or would choose to select in the wild. These modern practices have benefits but also potential disadvantages to the horse both nutritionally and behaviourally which may have an impact on welfare. This chapter highlights areas where dietary imbalances or inappropriate feeding practices may potentially have an adverse effect on welfare and gives suggestions on how these may be ameliorated.
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Couzin, I. D., Krause, J., James, R., Ruxton, G. D., & Franks, N. R. (2002). Collective Memory and Spatial Sorting in Animal Groups. J. Theor. Biol., 218(1), 1–11.
Abstract: We present a self-organizing model of group formation in three-dimensional space, and use it to investigate the spatial dynamics of animal groups such as fish schools and bird flocks. We reveal the existence of major group-level behavioural transitions related to minor changes in individual-level interactions. Further, we present the first evidence for collective memory in such animal groups (where the previous history of group structure influences the collective behaviour exhibited as individual interactions change) during the transition of a group from one type of collective behaviour to another. The model is then used to show how differences among individuals influence group structure, and how individuals employing simple, local rules of thumb, can accurately change their spatial position within a group (e.g. to move to the centre, the front, or the periphery) in the absence of information on their current position within the group as a whole. These results are considered in the context of the evolution and ecological importance of animal groups.
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Cooper, M. A., & Bernstein, I. S. (2002). Counter aggression and reconciliation in Assamese macaques (Macaca assamensis). Am. J. Primatol., 56(4), 215–230.
Abstract: Patterns of aggressive and affiliative behavior, such as counter aggression and reconciliation, are said to covary in the genus Macaca; this is referred to as the systematic variation hypothesis. These behavior patterns constitute a species dominance style. Van Schaik's [1989] socioecological model explains dominance style in macaques in terms of within- and between-group contest competition. Dominance style is also said to correlate with phylogeny in macaques. The present study was undertaken to examine phylogenetic and socioecological explanations of dominance style, as well as the systematic variation hypothesis. We collected data on counter aggression and reconciliation from a habituated group of Assamese macaques (Macaca assamensis) at the Tukeswari Temple in Assam, India. The proportion of agonistic episodes that involved counter aggression was relatively low. Counter aggression, however, occurred more often among males than among females, and it was most common when females initiated aggression against males. The conciliatory tendency for this group of Assamese macaques was 11.2%. The frequency of reconciliation was low for fights among males and for fights among females, but reconciliation was particularly rare for opposite-sexed opponents. Female social relationships were consistent with the systematic variation hypothesis, and suggest a despotic dominance style. A despotic dominance style in Assamese macaques weakens the correlation between dominance style and phylogeny in macaques, but it is not inconsistent with the socioecological model. Male-female relationships were not well explained by the despotic-egalitarian framework, and males may well have more tolerant social relationships than do females. Sex differences need to be considered when categorizing species according to dominance style.
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Cooper, J., & McGreevy, P. (2002). Stereotypic Behaviour in the Stabled Horse: Causes, Effects and Prevention without Compromising Horse Welfare. In The Welfare of Horses (pp. 99–124).
Abstract: Apparently functionless, repetitive behaviour in horses, such as weaving or crib-biting has been difficult to explain for behavioural scientists, horse owners and veterinarians alike. Traditionally activities such as these have been classed amongst the broad descriptor of undesirable stable vices and treatment has centred on prevention of the behaviours per se rather than addressing their underlying causes. In contrast, welfare scientists have described such activities as apparently abnormal stereotypics, claiming they are indicative of poor welfare, citing negative emotions such as boredom, frustration or aversion in the stable environment and even suggesting prevention of the activities alone can lead to increased distress. Our understanding of equine stereotypics has advanced significantly in recent years with epidemiological, developmental and experimental studies identifying those factors closely associated with the performance of stereotypics in stabled horses. These have allowed the development of new treatments based on removing the causal factors, improving the horses“ social and nutritional environment, re-training of horses and their owners and redirection of the activities to less harmful forms. Repetitive activities conventionally seen as undesirable responses to the stable environment, their causal basis and the effectiveness of different approaches to treatment are discussed, both in terms of reducing the behaviour and improving the horse”s quality of life.
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Clow, A., & Hucklebridge, F. (2002). International Review of Neurobiology: Neurobiology of the Immune System (Vol. 52). Amsterdam: Academic Press.
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Cloutier, S., Newberry, R. C., Honda, K., & Alldredge, J. R. (2002). Cannibalistic behaviour spread by social learning. Anim. Behav., 63(6), 1153–1162.
Abstract: We hypothesized that social learning is involved in the spread of cannibalism in domestic fowlGallus gallus domesticus . To investigate this hypothesis without harming birds, we used an inanimate chicken model as our cannibalism stimulus. We randomly assigned flocks of 12 White Leghorn pullets to one of two treatments: (1) flocks with two trained demonstrators (N=9) and (2) control flocks (N=8). Demonstrators were trained to pierce a membrane covering a dish of chicken blood and consume the blood. To assess the effect of access to the cannibalism stimulus during demonstrations, we randomly assigned observer pairs to one of two observer treatments: (1) observe stimulus through a wire mesh partition and (2) observe stimulus within the same enclosure. We conducted five 10-min demonstration sessions, each followed by a 10-min test of each observer pair in the absence of demonstrators, over a period of 15 days when the birds were 41-55 days of age, and two further tests at 63-64 and 91-92 days of age. Pairs that observed demonstrators piercing a membrane and consuming blood were more likely to perform this task when tested than control pairs. Learning of the task was enhanced by direct access to the cannibalism stimulus rather than observing it through a wire mesh partition. Blood consumption during tests was increased by direct access to the cannibalism stimulus during demonstration sessions. The birds made bigger holes in the membrane when tested after observing trained demonstrators and after having direct access to the stimulus. Our results provide the first experimental evidence that social learning can contribute to the spread of cannibalistic behaviour in domestic fowl. We suggest that stimulus enhancement and observational conditioning were the social-learning mechanisms involved. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.
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Cloutier, S., & Newberry, R. C. (2002). Differences in skeletal and ornamental traits between laying hen cannibals, victims and bystanders. Appl. Anim. Behav. Sci., 77(2), 115–126.
Abstract: We compared the size of skeletal and ornamental traits, and asymmetries in bilateral skeletal traits, between victims of cannibalism, cannibals and bystanders within small groups of caged female White Leghorns at the time of cannibalistic attacks (i.e. injurious pecks resulting in bleeding). We hypothesised that victims of cannibalism have discernible morphological traits that predispose them to cannibalistic attack. We predicted that victims would have smaller skeletal traits (body length, ulna length, metatarsus length and width, toe length), lower body weight, poorer body condition, smaller combs and more asymmetrical bilateral skeletal traits than their flock mates. Contrary to our prediction, victims of cannibalistic attacks to the head/neck area (N=23) tended to have larger combs than their flock mates (Wilcoxon matched-pairs signed-ranks test, S=59, P=0.037, NS after sequential Bonferroni adjustment). Their cannibals were more asymmetrical than non-cannibalistic bystanders (metatarsus length, S=48, P=0.011 and composite asymmetry, S=62.5, P=0.002, significant after sequential Bonferroni adjustment). In agreement with our prediction, victims of cannibalistic attacks to other body parts (N=27), including the back, wings, rump, tail, cloaca, abdomen and toes, were more asymmetrical (composite asymmetry, S=78, P=0.022, significant after sequential Bonferroni adjustment) and tended to have lower body weights (S=79.5, P=0.029, NS after sequential Bonferroni adjustment) than their flock mates. Their cannibals did not differ in skeletal or ornamental traits from the non-participating bystanders. The results suggest that large combs either elicit attacks to the head and neck area or increase vulnerability to injury during such attacks. Attacks to other body parts appear to be directed towards birds with signs of weakness relative to their flock mates. In these attacks, there were no distinguishing features separating cannibals from bystanders, suggesting that the bystanders could all be potential cannibals.
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Clement, T. S., & Zentall, T. R. (2002). Second-order contrast based on the expectation of effort and reinforcement. J Exp Psychol Anim Behav Process, 28(1), 64–74.
Abstract: Pigeons prefer signals for reinforcement that require greater effort (or time) to obtain over those that require less effort to obtain (T. S. Clement, J. Feltus, D. H. Kaiser, & T. R. Zentall, 2000). Preference was attributed to contrast (or to the relatively greater improvement in conditions) produced by the appearance of the signal when it was preceded by greater effort. In Experiment 1, the authors of the present study demonstrated that the expectation of greater effort was sufficient to produce such a preference (a second-order contrast effect). In Experiments 2 and 3, low versus high probability of reinforcement was substituted for high versus low effort, respectively, with similar results. In Experiment 3, the authors found that the stimulus preference could be attributed to positive contrast (when the discriminative stimuli represented an improvement in the probability of reinforcement) and perhaps also negative contrast (when the discriminative stimuli represented reduction in the probability of reinforcement).
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