|
|
Munksgaard, L., DePassillé, A. M., Rushen, J., Herskin, M. S., & Kristensen, A. M. (2001). Dairy cows' fear of people: social learning, milk yield and behaviour at milking. Appl. Anim. Behav. Sci., 73(1), 15–26.
Abstract: We examined the effects of the presence of an unfamiliar, a gentle or an aversive handler during milking on behaviour and milk yield, and whether cows can learn to approach or avoid a handler by observing the neighbouring cow?s responses. In Experiment 1, Danish Friesian cows (n=16) were treated gently (offering hay and concentrates) by one handler and aversively (hit every 15s on the head with the hand) by another handler for six periods of 2min each. The two handlers wore different coloured overalls, and each cow received either gentle or aversive treatment in the first week and the other treatment the following week. All cows kept a longer distance to the aversive than to the gentle handler in a 1min test after treatment. Milk yield and residual milk did not differ when the aversive or the gentle handler was standing in front of the cow during milking, although the cows moved their legs and tail less when the aversive handler was present. When an unfamiliar person was standing in front of the cows during milking, behaviour and milk yield did not differ from control milkings. Cows and heifers (n=10) that had observed their neighbours receiving gentle treatment by one handler and aversive treatment from another handler did not differ in the distance they kept from these two handlers. In Experiment 2, cows (n=15) that had observed the neighbours receiving a gentle treatment (eight times for 2min) kept a shorter distance to that handler after treatment of their neighbours, and the distance they kept was correlated with the distance kept by the neighbouring cows. This suggests that responses of observer cows may be affected by the responses of the cows being treated. The cows rapidly learned to avoid an aversive handler, but although the cows showed clear avoidance response to the aversive handler there was no effect on milk yield when the aversive handler was present at milking.
|
|
|
|
Morley, K. I., & Montgomery, G. W. (2001). The genetics of cognitive processes: candidate genes in humans and animals. Behav Genet, 31(6), 511–531.
Abstract: It has been hypothesized that numerous genes contribute to individual variation in human cognition. An extensive search of the scientific literature was undertaken to identify candidate genes which might contribute to this complex trait. A list of over 150 candidate genes that may influence some aspect of cognition was compiled. Some genes are particularly strong candidates based on evidence for involvement in cognitive processes in humans, mice, and Drosophila melanogaster. This survey confirms that many genes are associated with cognitive variation and highlights the potential importance of animal models in the study of human cognition.
|
|
|
|
Bouchard, T. J. J., & Loehlin, J. C. (2001). Genes, evolution, and personality. Behav Genet, 31(3), 243–273.
Abstract: There is abundant evidence, some of it reviewed in this paper, that personality traits are substantially influenced by the genes. Much remains to be understood about how and why this is the case. We argue that placing the behavior genetics of personality in the context of epidemiology, evolutionary psychology, and neighboring psychological domains such as interests and attitudes should help lead to new insights. We suggest that important methodological advances, such as measuring traits from multiple viewpoints, using large samples, and analyzing data by modern multivariate techniques, have already led to major changes in our view of such perennial puzzles as the role of “unshared environment” in personality. In the long run, but not yet, approaches via molecular genetics and brain physiology may also make decisive contributions to understanding the heritability of personality traits. We conclude that the behavior genetics of personality is alive and flourishing but that there remains ample scope for new growth and that much social science research is seriously compromised if it does not incorporate genetic variation in its explanatory models.
|
|
|
|
Zentall, T. R. (2001). The case for a cognitive approach to animal learning and behavior. Behav Processes, 54(1-3), 65–78.
Abstract: The dangers of hypothesizing about unobservable cognitive mechanisms are well known to behavior analysts. I propose, however, that carefully fashioned cognitive theories that make predictions that are inconsistent with current behavioral theories can provide useful research tools for the understanding of behavior. Furthermore, even if the results of such research may be accommodated by modifying existing behavioral theories, our understanding of behavior is often advanced by the empirical findings because it is unlikely that the research would have been conducted in the absence of such cognitive hypothesizing. Two examples of the development of emergent relations are described: The first deals with the nature of a pigeon's 'representation' of two stimuli both of which are associated with correct responding to a third in a many-to-one matching task (stimulus equivalence or common representations). The second has to do with transitive inference, the emergent relation between two stimuli mediated by their relation to a common stimulus in a simultaneous discrimination.
|
|
|
|
Gibson, B. M., Shettleworth, S. J., & McDonald, R. J. (2001). Finding a goal on dry land and in the water: differential effects of disorientation on spatial learning. Behav. Brain. Res., 123(1), 103–111.
Abstract: Two previous studies, Martin et al. (J. Exp. Psychol. Anim. Behav. Process. 23 (1997) 183) and Dudchenko et al. (J. Exp. Psychol. Anim. Behav. Process. 23 (1997) 194), report that, compared to non-disoriented controls, rats disoriented before testing were disrupted in their ability to learn the location of a goal on a dry radial-arm maze task, but that both groups learned at the same rate in the Morris water maze. However, the radial-arm maze task was much more difficult than the water maze. In the current set of experiments, we examined the performance of control and disoriented rats on more comparable dry land and water maze tasks. Compared to non-disoriented rats, rats that were disoriented before testing were significantly impaired in locating a goal in a circular dry arena, but not a water tank. The results constrain theoretical explanations for the differential effects of disorientation on different spatial tasks.
|
|
|
|
Dugatkin, L. A. (2001). Bystander effects and the structure of dominance hierarchies. Behav. Ecol., 12(3), 348–352.
Abstract: Prior modeling work has found that pure winner and loser effects (i.e., changing the estimation of your own fighting ability as a function of direct prior experience) can have important consequences for hierarchy formation. Here these models are extended to incorporate “bystander effects.” When bystander effects are in operation, observers (i.e., bystanders) of aggressive interactions change their assessment of the protagonists' fighting abilities (depending on who wins and who loses). Computer simulations demonstrate that when bystander winner effects alone are at play, groups have a clear omega (bottom-ranking individual), while the relative position of other group members remains difficult to determine. When only bystander loser effects are in operation, wins and losses are randomly distributed throughout a group (i.e., no discernible hierarchy). When pure and bystander winner effects are jointly in place, a linear hierarchy, in which all positions (i.e., {alpha} to {delta} when N = 4) are clearly defined, emerges. Joint pure and bystander loser effects produce the same result. In principle one could test the predictions from the models developed here in a straightforward comparative study. Hopefully, the results of this model will spur on such studies in the future.
|
|
|
|
Anderson, C., & Franks, N. R. (2001). Teams in animal societies. Behav. Ecol., 12(5), 534–540.
Abstract: We review the existence of teams in animal societies. Teams have previously been dismissed in all but a tiny minority of insect societies. “Team” is a term not generally used in studies of vertebrates. We propose a new rigorous definition of a team that may be applied to both vertebrate and invertebrate societies. We reconsider what it means to work as a team or group and suggest that there are many more teams in insect societies than previously thought. A team task requires different subtasks to be performed concurrently for successful completion. There is a division of labor within a team. Contrary to previous reviews of teams in social insects, we do not constrain teams to consist of members of different castes and argue that team members may be interchangeable. Consequently, we suggest that a team is simply the set of individuals that performs a team task. We contrast teams with groups and suggest that a group task requires the simultaneous performance and cooperation of two or more individuals for successful completion. In a group, there is no division of labor--each individual performs the same task. We also contrast vertebrate and invertebrate teams and find that vertebrate teams tend to be associated with hunting and are based on individual recognition. Invertebrate teams occur in societies characterized by a great deal of redundancy, and we predict that teams in insect societies are more likely to be found in large polymorphic (“complex”) societies than in small monomorphic (“simple”) societies.
|
|
|
|
Doutrelant, C., McGregor, P. K., & Oliveira, R. F. (2001). The effect of an audience on intrasexual communication in male Siamese fighting fish, Betta splendens. Behav. Ecol., 12, 283–286.
|
|
|
|
Zuberbühler, K. (2001). Predator-specific alarm calls in Campbell's monkeys, Cercopithecus campbelli. Behav. Ecol. Sociobiol., 50(5), 414–422.
Abstract: One of the most prominent behavioural features of many forest primates are the loud calls given by the adult males. Early observational studies repeatedly postulated that these calls function in intragroup spacing or intergroup avoidance. More recent field experiments with Diana monkeys (Cercopithecus diana) of Taï Forest, Ivory Coast, have clearly shown that loud male calls function as predator alarm calls because calls reliably (1) label different predator classes and (2) convey semantic information about the predator type present. Here, I test the alarm call hypothesis another primate, the Campbell's monkey (C. campbelli). Like Diana monkeys, male Campbell's monkeys produce conspicuous loud calls to crowned hawk eagles (Stephanoaetus coronatus) and leopards (Panthera pardus), two of their main predators. Playback experiments showed that monkeys responded to the predator category represented by the different playback stimuli, regardless of whether they consisted of (1) vocalisations of the actual predators (crowned hawk eagle shrieks or leopard growls), (2) alarm calls to crowned hawk eagles or leopards given by other male Campbell's monkeys or (3) alarm calls to crowned hawk eagles or leopards given by sympatric male Diana monkeys. These experiments provide further evidence that non-human primates have evolved the cognitive capacity to produce and respond to referential labels for external events.
|
|
|
|
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.
|
|
