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.

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.

Abstract: To investigate whether learning to discriminate between visual compound stimuli depends on decomposing them into constituting features, hens were first trained to discriminate four features (red, green, horizontal, vertical) from two dimensions (colour, line orientation). After acquisition, hens were trained with compound stimuli made up from these dimensions in two ways: a separable (line on a coloured background) stimulus and an integral one (coloured line). This compound training included a reversal of reinforcement of only one of the two dimensions (half-reversal). After having achieved the compound stimulus discrimination, a second dimensional training identical to the first was performed. Finally, in the second compound training the other dimension was reversed. Two major results were found: (1) an interaction between the dimension reversed and the type of compound stimulus: in compound training with colour reversal, separable compound stimuli were discriminated worse than integral compounds and vice versa in compound training with line orientation reversed. (2) Performance in the second compound training was worse than in the first one. The first result points to a similar mode of processing for separable and integral compounds, whereas the second result shows that the whole stimulus is psychologically superior to its constituting features. Experiment 2 repeated experiment 1 using line orientation stimuli of reversed line and background brightness. Nevertheless, the results were similar to experiment 1. Results are discussed in the framework of a configural exemplar theory of discrimination that assumes the representation of the whole stimulus situation combined with transfer based on a measure of overall similarity.

Abstract: Animal welfare, or well-being, is a social issue with ethical, scientific, political, and aesthetic properties. Answering questions about the welfare of animals requires scientific definition, assessment, solutions, and public acceptance. With respect to the actual well-being of the animal, most issues are centered on how the animal “feels” when managed within a specific level of confinement, during special agricultural practices (e.g., tail docking, beak trimming, etc.) and handling. Questions of this nature may require exploration of animal cognition, motivation, perception, and emotional states in addition to more commonly recognized indicators of well-being. Several general approaches have emerged for solving problems concerning animal well-being in intensive production systems: environmental, genetic, and therapeutic. Environmental approaches involve modifying existing systems to accommodate specific welfare concerns or development of alternative systems. Genetic approaches involve changing the behavioral and (or) physiological nature of the animal to reduce or eliminate behaviors that are undesirable within intensive system. Therapeutic approaches of a physical (tail docking, beak trimming) and physiological (drug and nutritional therapy) nature bring both concern and promise with regard to the reduction of confinement stress. Finally, the recent focus on commodity quality assurance programs may indirectly provide benefits for animal well-being. Although research in the area of animal well-being will provide important information for better animal management, handling, care, and the physical design of intensive production systems there is still some uncertainty regarding public acceptance. The aesthetics of modern intensive production systems may have as much to do with public acceptance as with science.

Abstract: 1. The aim of the study was to compare the management and husbandry of free-range flocks in the UK where feather pecking was either present (case) or absent (control). 2. One hundred flocks were enrolled into a concurrent case-control study: 50 where birds had recently started feather pecking, and 50 matched control flocks where birds of the same age had not started feather pecking. 3. Information was obtained from a detailed interview with the flock manager, and by direct inspection of the flock, house and range. 4. Initial univariate analyses revealed that case flocks were more likely to comprise ISA Brown than Lohmann, were more likely to be restricted from litter areas to prevent floor eggs, and were less likely to use the outside range. 5. Cluster analysis indicated that feather pecking was not associated with any particular husbandry system. 6. The only influential risk factor significant in the multivariable conditional logistic regression analysis was use of the outdoor range. The risk of feather pecking was reduced 9-fold in flocks where more than 20% of birds used the range on sunny days (odds ratio = 0.12). Use of the range was positively associated with the presence of trees and/or hedges on the range.