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Petherick, J. C., Waddington, D., & Duncan, I. J. H. (1991). Learning to gain access to a foraging and dustbathing substrate by domestic fowl: is `out of sight out of mind'? Behav. Process., 22(3), 213–226.
Abstract: Domestic fowl were deprived of the opportunity to perform litter-related behaviour for three or four days and were tested in a Y-maze (which they had previously been trained to run) for their ability to associate a coloured cue with gaining access to peat. When the goal boxes were within sight of the choice point, most birds chose peat. However, when the birds had to rely solely on the coloured cue only one bird from 12 showed learning. However, the birds seemed to have some expectation of a reward, as they ran faster if, on the previous trial, they had chosen peat. The inability of the birds to learn the association may have been an artefact of the schedule of deprivation and testing, for when they were hungry and tested in the same way they were again unable to learn an association between the same coloured cue and food reward. The experiment with peat was repeated using “massed” trials (several trials in immediate succession) during training and testing and six from 15 birds showed learning. These results suggest that the initial failure to learn was probably due to the training and testing schedule, that access to peat appears to be rewarding and that hens can learn an association between an abstract cue and a rewarding consequence. This is consistent with the possibility that domestic fowls may have some cognitive representation of peat when it is out of sight.
Keywords: Domestic fowl; Dustbathing; Welfare; Learning; Cognition
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Vallortigara, G., & Andrew, R. J. (1994). Differential involvement of right and left hemisphere in individual recognition in the domestic chick. Behav. Process., 33(1-2), 41–57.
Abstract: Right hemisphere advantage in individual recognition (as shown by differences between response to strangers and companions) is clear in the domestic chick. Chicks using the left eye (and so, thanks to the complete optic decussation, predominantly the right hemisphere) discriminate between stranger and companion. Chicks using the right eye discriminate less clearly or not at all. The ability of left eyed chicks to respond to differences between strangers and companions stimuli is associated with a more general ability to detect and respond to novelty: this difference between left and right eyed chicks also holds for stimuli which are not social partners. The right hemisphere also shows advantage in tasks with a spatial component (topographical learning; response to change in the spatial context of a stimulus) in the chick, as in humans. Similar specialisations of the two hemispheres are also revealed in tests which involve olfactory cues presented by social partners. The special properties of the left hemisphere are less well established in the chick. Evidence reviewed here suggests that it tends to respond to selected properties of a stimulus and to use them to assign it to a category; such assignment then allows an appropriate response. When exposed to an imprinting stimulus (visual or auditory) a chick begins by using right eye or ear (suggesting left hemisphere control), and then shifts to the left eye or ear (suggesting right hemisphere control), as exposure continues. The left hemisphere here is thus involved whilst behaviour is dominated by vigorous response to releasing stimuli presented by an object. Subsequent learning about the full detailed properties of the stimulus, which is crucial for individual recognition, may explain the shift to right hemisphere control after prolonged exposure to the social stimulus. There is a marked sex difference in choice tests: females tend to choose companions in tests where males choose strangers. It is possible that this difference is specifically caused by stronger motivation to sustain social contact in female chicks, for which there is extensive evidence. However, sex differences in response to change in familiar stimuli are also marked in tests which do not involve social partners. Finally, in both sexes there are two periods during development in which there age-dependent shifts in bias to use one or other hemisphere. These periods (days 3-5 and 8-11) coincide with two major changes in the social behaviour of chicks reared by a hen in a normal brood. It is argued that one function of these periods is to bring fully into play the hemisphere most appropriate to the type of response to, and learning about, social partners which is needed at particular points in development. Parallels are discussed between the involvement of lateralised processes in the recognition of social partners in chicks and humans.
Keywords: Right hemisphere; Left hemisphere; Domestic fowl; Lateralization; Chick
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Hogue, M. - E., Beaugrand, J. P., & Lague, P. C. (1996). Coherent use of information by hens observing their former dominant defeating or being defeated by a stranger. Behav. Process., 38(3), 241–252.
Abstract: This study examines the role of observation during the formation of triads in female domestic hens. Results indicate that during hierarchy formation, a hen observing agonistic interactions and conflict settlement between its former dominant and a stranger uses this information when in turn confronted by the latter. Under a first condition (E, N = 15 triads), bystanders witnessed their prior dominant being defeated by a stranger before being introduced to them. In a second condition (C1, N = 16 triads), bystanders witnessed the victory of their prior dominant over a stranger. In a third condition (C2, N = 15 triads), bystanders witnessed two strangers establishing a dominance relationship before being introduced to their prior dominant and to a stranger the former had just defeated. The behavioural strategies of bystanders depended on the issue of the conflict they had witnessed. Bystanders of the E condition behaved as having no chance of defeating the stranger. They never initiated an attack against it, and upon being attacked, readily submitted in turn to the stranger. On the contrary, bystanders of the C1 condition behaved as having some chances against the stranger. They initiated attacks in 50% of cases, and won 50% of conflicts against the stranger. Under condition C2, bystanders first initiated contact with the strangers in only 27% of cases, which approximates the average of their chances for defeating the stranger. However, bystanders finally defeated the strangers in 40% of cases. These results suggest that bystanders of conditions E and C1 gained some information on the relationship existing between their prior dominant and the stranger and that they used it coherently, perhaps through transitive inference, thus contributing to the existence of transitive relationships within the triads. Alternate explanations are examined.
Keywords: Domestic fowl; Dominance; Hierarchy formation; Observation; Transitive inference
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Abeyesinghe, S. M., Nicol, C. J., Wathes. C.M., & Randall, J. M. (2001). Development of a raceway method to assess aversion of domestic fowl to concurrent stressors. Behav. Process., 56(3), 175–194.
Abstract: The requirement for assessing the effects of stressor combinations in improving the welfare of animals has not been widely recognised. Knowledge of the effects of concurrent stressors is needed to improve environments such as transport, where animals are presented with many simultaneous challenges. However, no method for measuring the effects of different stressors with a common unit is currently available. A locomotor passive avoidance method was developed as a common currency measure of the aversion of domestic fowl to concurrent stressors, using vibrational and thermal stressors as an exemplar. Juvenile fowl, fasted overnight, were trained to run a raceway into a goal-box for small food rewards (FR1). When running consistently, the reinforcement schedule was superimposed with a FR5 treatment schedule (60 min confinement in the goal-box with either a control of no other stressors [N] or concurrent vibration and thermal stressors [VT]). Subsequent latency to return to the goal-box was recorded as a measure of aversion. The factors affecting bird response were addressed in a series of experiments to optimise the method and clarify interpretation of results. Pre-feeding (20% ration 2 h prior to testing) did not affect response, but increasing the number of treatment presentations facilitated learning and increased method sensitivity. Treatment responses were consistent across experiments; overall VT was avoided (P<0.001), but N was not. However, there was large individual variation in response to VT. A final experiment indicated that, given a visual discriminatory cue, birds were capable of learning the required association between entering the goal-box and receiving the treatment, suggesting that the delay responses were due to aversion rather than the immediate impact of treatment on ability to respond. Further work is required to test the singular stressors, but the method retains common currency potential for assessing aversion to multiple stressors.
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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.
Keywords: Domestic fowl; Asymmetry; Skeletal traits; Comb size; Cannibalism
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Wilson, R. T. (2003). Biodiversity of Domestic Livestock in the Republic of Yemen. Tropical Animal Health and Production, 35(1), 27–46.
Abstract: Abstract This paper describes the domestic livestock of the Republic of Yemen and aspires to complement earlier sources listing or partially describing `breeds'. It attempts to cover all species and provide indications of production parameters through a literature review and via field observations made by the author in 1999. Information is provided on livestock numbers and the economic importance of animal production. Most animals are kept in sedentary mixed crop-livestock production systems; transhumant systems have the next greatest number of stock; with nomadic systems being of least and declining importance. Yemen's livestock appear to comprise at least 11 breeds of sheep, 5 breeds of goat, 2 breeds of cattle, 4 breeds of camel, 2 breeds of donkey and 1 breed of horse. There are no data on breeds of poultry but domestic fowl (where clearly considerable diversity exists) and pigeons are kept. There is little formal information on the history and relationships of most breeds. Some appear to be of ancient local origin, whereas others show affinities with those of neighbouring and other countries. None of the identified types is considered endangered, so conservation would be premature. A more formal and detailed genetic characterization, to add to the largely morphological and traditional classification, may, however, reveal such a need.
Keywords: Abstract This paper describes the domestic livestock of the Republic of Yemen and aspires to complement earlier sources listing or partially describing `breeds'. It attempts to cover all species and provide indications of production parameters through a literature review and via field observations made by the author in 1999. Information is provided on livestock numbers and the economic importance of animal production. Most animals are kept in sedentary mixed crop-livestock production systems; transhumant systems have the next greatest number of stock; with nomadic systems being of least and declining importance. Yemen's livestock appear to comprise at least 11 breeds of sheep, 5 breeds of goat, 2 breeds of cattle, 4 breeds of camel, 2 breeds of donkey and 1 breed of horse. There are no data on breeds of poultry but domestic fowl (where clearly considerable diversity exists) and pigeons are kept. There is little formal information on the history and relationships of most breeds. Some appear to be of ancient local origin, whereas others show affinities with those of neighbouring and other countries. None of the identified types is considered endangered, so conservation would be premature. A more formal and detailed genetic characterization, to add to the largely morphological and traditional classification, may, however, reveal such a need.
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