| Home | << 1 2 3 4 >> |
|
Foster, T. M., Temple, W., Cameron, B., & Poling, A. (1997). Demand curves for food in hens: Similarity under fixed-ratio and progressive-ratio schedules. Behav. Process., 39(2), 177–185.
Abstract: Demand curves were generated for five domestic hens under progressive-ratio 5 schedules of food delivery and under fixed-ratio schedules of food delivery that began at fixed-ratio 5 and were incremented by 5 each session. All sessions ended after 10 consecutive minutes without a response. Although response rates at a given ratio were higher under the progressive-ratio schedule, all hens completed higher ratios under the fixed-ratio schedule. Similar, but not identical, demand curves were generated under progressive-ratio and fixed-ratio schedules. Under both schedules, consumption (reinforcers earned) decreased as cost (ratio size) increased. Data generally were well described by an equation in which elasticity of demand is constant, although an equation in which elasticity could vary accounted for slightly more of the variance.
|
|
Rogers, L. J. (2000). Evolution of hemispheric specialization: advantages and disadvantages. Brain Lang, 73(2), 236–253.
Abstract: Lateralization of the brain appeared early in evolution and many of its features appear to have been retained, possibly even in humans. We now have a considerable amount of information on the different forms of lateralization in a number of species, and the commonalities of these are discussed, but there has been relatively little investigation of the advantages of being lateralized. This article reports new findings on the differences between lateralized and nonlateralized chicks. The lateralized chicks were exposed to light for 24 h on day 19 of incubation, a treatment known to lead to lateralization of a number of visually guided responses, and the nonlateralized chicks were incubated in the dark. When they were feeding, the lateralized chicks were found to detect a stimulus resembling a raptor with shorter latency than nonlateralized chicks. This difference was not a nonspecific effect caused by the light-exposed chicks being more distressed by the stimulus. Instead, it appears to be a genuine advantage conferred by having a lateralized brain. It is suggested that having a lateralized brain allows dual attention to the tasks of feeding (right eye and left hemisphere) and vigilance for predators (left eye and right hemisphere). Nonlateralized chicks appear to perform these dual tasks less efficiently than lateralized ones. Reference is made to other species in discussing these results.
|
|
Wilkins, L. J., Brown, S. N., Zimmerman, P. H., Leeb, C., & Nicol, C. J. (2004). Investigation of palpation as a method for determining the prevalence of keel and furculum damage in laying hens. Vet. Rec., 155(18), 547–549.
Abstract: Old breaks of the keel and furculum were identified by palpation in 500 end-of-lay hens from 10 flocks housed in free-range and barn systems, and the results were compared with the results obtained by a full dissection and inspection. The method was considered to be sufficiently precise to be used as a diagnostic tool although people using it would need to be trained. The results obtained by dissection indicated that 50 to 78 per cent of the birds in the flocks had breaks of the furculum and keel, but no other breaks of bones were detected.
Keywords: Animal Husbandry/methods; Animal Welfare; Animals; Bone and Bones/*injuries; Chickens/*injuries; Female; Fractures, Bone/diagnosis/epidemiology/*veterinary; Great Britain/epidemiology; Housing, Animal/standards; Oviposition; Palpation/methods/*veterinary; Poultry Diseases/*diagnosis/epidemiology; Prevalence; Sensitivity and Specificity
|
|
Croney, C. C., Prince-Kelly, N., & Meller, C. L. (2007). A note on social dominance and learning ability in the domestic chicken (Gallus gallus). Appl. Anim. Behav. Sci., 105(1-3), 254–259.
Abstract: Relatively little is known about the relationship between social behavior and specific cognitive abilities of the chicken. It is uncertain whether dominant birds have a cognitive advantage over subordinate birds that might facilitate their superior position in the social hierarchy. Likewise, it is unknown whether subordinate birds compete successfully with higher ranking birds because their cognitive capacities compensate for physical deficits. In this study, the relationship between the chicken's position in the dominance hierarchy and its performance on a cognitive task was explored. Ten pairs of New Hampshire domestic roosters (Gallus gallus) were observed to determine dominance or subordinance within dyads. All birds were then trained and tested on a visual discrimination learning task. Discriminative stimuli were orange and green plastic discs. Correct stimuli (orange or green) were randomly assigned to birds. Placement of the discs (left or right of center) was also randomly assigned and counterbalanced to avoid a side bias. Birds were rewarded with food for pecking at the correct disc. Criterion for task completion was 80% correct responses on three consecutive test sessions or 86% correct on two consecutive sessions. All subjects met the test criterion. The number of trials to criterion was compared between dominant and subordinate birds using a paired t-test. No difference was found in performance between dominant and subordinate birds (p > 0.05) suggesting that in chickens, ability to learn a novel visual discrimination task is not well correlated with rank. Additional studies, particularly using different learning paradigms, are needed to confirm these results.
|
|
Nicol, C. J. (2006). How animals learn from each other. Appl. Anim. Behav. Sci., 100(1-2), 58–63.
Abstract: This paper explores ways by which animals may learn from one another, using examples drawn mostly from the chicken, an animal for which social learning is likely to be less dangerous than individual learning. In early life, the behaviour of the hen is important in encouraging chicks to peck at edible items. Maternal display not only attracts chicks to profitable food items, but also redirects their attention away from harmful or non-profitable items. Older chicks can enhance their foraging success by observing the behaviour of conspecifics within their own social group. Hens have been trained to perform a novel behaviour (key-pecking for food) by observation of a trained demonstrator bird. Moreover, observers learnt most from watching dominant demonstrators. Thus the ability to learn from others is not `fixed', but depends on the context and the social identity of both the observer and the demonstrator.
Keywords: Social learning; Chickens; Demonstrators; Dominance
|
|
Houpt, K. A. (1976). Animal behavior as a subject for veterinary students. Cornell Vet, 66(1), 73–81.
Abstract: Knowledge of animal behavior is an important asset for the veterinarian; therefore a course in veterinary animal behavior is offered at the New York State College of Veterinary Medicine as an elective. The course emphasizes the behavior of those species of most interest to the practicing veterinarian: cats, dogs, horses, cows, pigs and sheep. Dominance heirarchies, animal communication, aggressive behavior, sexual behavior and maternal behavior are discussed. Play, learning, diurnal cycles of activity and sleep, and controls of ingestive behavior are also considered. Exotic and zoo animal behaviors are also presented by experts in these fields. The critical periods of canine development are related to the optimum management of puppies. The behavior of feral dogs and horses is described. The role of the veterinarian in preventing cruelty to animals and recognition of pain in animals is emphasized. Whenever possible behavior is observed in the laboratory or on film.
|
|
Dixon, G., Green, L. E., & Nicol, C. J. (2006). Effect of diet change on the behavior of chicks of an egg-laying strain. J Appl Anim Welf Sci, 9(1), 41–58.
Abstract: Injurious pecking has serious welfare consequences in flocks of hens kept for egg laying, especially when loose-housed. Frequent diet change is a significant risk for injurious pecking; how the mechanics of diet change influence pecking behavior is unknown. This study investigated the effect of diet change on the behavior of chicks from a laying strain. The study included a 3-week familiarity phase: 18 chick pairs received unflavored feed (Experiment 1); 18 pairs received orange oil-flavored (Experiment 2). All chicks participated in a dietary preference test (P); a diet change (DC); or a control group (C), 6 scenarios. All P chicks preferred unflavored feed. In Experiment 1, DC involved change from unflavored to orange-flavored; Experiment 2, orange- flavored to unflavored. Compared with controls, Experiment 2 DC chicks exhibited few behavioral differences; Experiment 1 DC chicks exhibited increased behavioral event rates on Days 1 and 7. They pecked significantly longer at their environment; by Day 7, they showed significantly more beak activity. There was little evidence of dietary neophobia. Change from more preferred to less preferred feed led to increased activity and redirected pecking behavior.
|
|
Haslam, S. M., Brown, S. N., Wilkins, L. J., Kestin, S. C., Warriss, P. D., & Nicol, C. J. (2006). Preliminary study to examine the utility of using foot burn or hock burn to assess aspects of housing conditions for broiler chicken. Br Poult Sci, 47(1), 13–18.
Abstract: 1. Eleven broiler chicken farms, representing 4 production system types, were visited during the last 5 d of the flock cycle: bird and flock details were recorded. Litter friability was assessed at 9 sites within the house, atmospheric ammonia was measured at three sites and bird cleanliness was assessed on a numerical rating scale. 2. For these flocks, hock burn, foot burn and breast burn were measured at the processing plant by standardised assessors. 3. Significant correlations were identified between the percentage of birds with foot burn and average litter score, average house ammonia concentrations and feather score. 4. No correlation was found between the percentage of birds with hock burn or breast burn and average litter scores, average ammonia concentrations or feather score. 5. No correlation was found between stocking density and foot burn, hock burn or breast burn.6. If confirmed, these findings may have implications for the draft EU Broiler Directive, for which it is proposed that permitted stocking density on farm may be determined by the incidence and severity of contact dermatitis measured on plant.
|
|
Nicol, C. J. (2004). Development, direction, and damage limitation: social learning in domestic fowl. Learn Behav, 32(1), 72–81.
Abstract: This review highlights two areas of particular interest in the study of social learning in fowl. First, the role of social learning in the development of feeding and foraging behavior in young chicks and older birds is described. The role of the hen as a demonstrator and possible teacher is considered, and the subsequent social influence of brood mates and other companions on food avoidance and food preference learning is discussed. Second, the way in which work on domestic fowl has contributed to an understanding of the importance of directed social learning is examined. The well-characterized hierarchical social organization of small chicken flocks has been used to design studies which demonstrate that the probability of social transmission is strongly influenced by social relationships between birds. The practical implications of understanding the role of social learning in the spread of injurious behaviors in this economically important species are briefly considered.
|
|
Freire, R., Wilkins, L. J., Short, F., & Nicol, C. J. (2003). Behaviour and welfare of individual laying hens in a non-cage system. Br Poult Sci, 44(1), 22–29.
Abstract: 1. A leg band containing a transponder was fitted to 80 birds in a perchery containing 1,000 birds. 2. The transponder emitted a unique identification number when a bird walked on one of 8 flat antennae on the floor. The recording apparatus was used to measure the amount of time that each of the tagged birds spent on the slatted and littered areas in a 6-week period. 3. Some birds spent long periods of time on the slats, possibly as a means of avoiding repeated attacks. Duration on the slats was greatest in birds with the worst (as opposed to better) feather scores of the head, back and tail regions. 4. Birds that spent long periods on the slats were lighter than other birds at both 39 weeks of age and 72 weeks of age and had greater back, head and tail feather damage, consistent with these birds being victims of pecking. 5. Tagged birds received a social avoidance test outside the perchery at 39 weeks of age, which suggested that birds retreated to the slats in response to pecks rather than just to close proximity to other birds. 6. The failure to find that duration on the slats was related to anatomical indicators of stress (liver, spleen and bursa of Fabricius) suggests that retreating to the slats following pecking attenuates physiological stress responses. 7. We conclude that the provision of areas where birds in a large group can avoid pecking may improve the welfare of a minority of victimised birds.
|