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Hanggi, E. B., & Ingersoll, J. F. (2009). Long-term memory for categories and concepts in horses (Equus caballus). Anim. Cogn., 13(3), 451–462.
Abstract: Three horses (Equus caballus) with a history of performing cognitive tasks including discrimination learning, categorization, and concept use were tested to evaluate their long-term memory (LTM) in three experiments. In addition, use of LCD multi-displays for stimulus presentation was incorporated into cognition testing protocol for the first time with horses. Experiment 1 tested LTM for discrimination learning that originally occurred 6 years earlier. Five sets of stimuli were used and the two horses tested showed no decrement in performance on four of the sets; however, both horses did score below chance on one set. Experiment 2 examined long-term categorization recall 10 years after horses had demonstrated the ability to make stimulus selections based on shared characteristics within a given category. The horse tested for LTM after the decade-long interval immediately and consistently applied the previously learned categorization rule to not only familiar but also novel sets of stimuli. Experiment 3 tested another horse for LTM for a relative size concept. This horse had originally demonstrated concept rule use in order to select stimuli based on their relative size to one another. More than 7 years later and without further training, this horse reliably applied the previously established size concept to both familiar and novel sets of stimuli. These findings are the first reports of long-term categorical and conceptual memory in horses and are consistent with observations of domestic and wild horses, which indicate that behavioral and ecological events may be remembered for long periods of time. These studies also demonstrate the adaptive nature of horses with regard to their ability to generalize over several different testing conditions.
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Kerr, R. A. (2006). PALEOCLIMATOLOGY. Atlantic mud shows how melting ice triggered an ancient chill. Science, 312(5782), 1860.
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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.
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Lensink, J., Veissier, I., & Boissy, A. (2006). Enhancement of performances in a learning task in suckler calves after weaning and relocation: Motivational versus cognitive control?: A pilot study. Appl. Anim. Behav. Sci., 100(3-4), 171–181.
Abstract: Weaning in suckler calves influences performance in a learning task. The aim of the present study was to investigate whether the improved performance after weaning, including relocation, is due to differences in motivation for the reward or in learning abilities. Forty Aubrac calves were used; half of them were weaned from their dams at around eight months, the other half were weaned one month later. After weaning, calves were housed in groups of four in a new setting. From the day after weaning of the last group of calves, the animals were subjected to two tests: (1) an arena test, (2) a T-maze test where one arm led to either a social or a food reward. The T-maze test consisted of three sessions: in Session 1, trials were conducted until the animal acquired the task (i.e. did not take the unrewarded arm on three consecutive trials); in Session 2, the motivation for the reward was assessed via the walking time of the animal to reach the reward; in Session 3, the place of reward was reversed and the animals were trained until they acquired the new task. Calves weaned for one day explored more (P < 0.05) and had lower heart rates during the arena test (P < 0.05) compared to the ones weaned for one month. During the T-maze test, calves weaned for one month versus one day did not differ in their capacities to learn the initial route (Session 1) or in their motivation for either the social or food reward (Session 2). Calves weaned for one day learned significantly faster (P < 0.05) the reversed route (Session 3) than calves weaned for one month. Hence, the better performances at reversal in the T-maze by calves that have just been weaned cannot be accounted for by a higher motivation for the reward. A better cognitive control of their behaviour due to a lower stress state is suggested by our results.
Keywords: Calves; Weaning; Learning; Cognition; Behavioural test
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Melis, A. P., Hare, B., & Tomasello, M. (2006). Engineering cooperation in chimpanzees: tolerance constraints on cooperation. Anim. Behav., 72(2), 275–286.
Abstract: The cooperative abilities of captive chimpanzees, Pan troglodytes, in experiments do not match the sophistication that might be predicted based on their naturally occurring cooperative behaviours. This discrepancy might partly be because in previous experiments potential chimpanzee cooperators were partnered without regard to their social relationship. We investigated the ability of chimpanzee dyads to solve a physical task cooperatively in relation to their interindividual tolerance levels. Pairs that were most capable of sharing food outside the test were also able to cooperate spontaneously (by simultaneously pulling two ropes) to obtain food. In contrast, pairs that were less inclined to share food outside of the test were unlikely to cooperate. Furthermore, previously successful subjects stopped cooperating when paired with a less tolerant partner, even when the food rewards were presented in a dispersed and divisible form to reduce competition between subjects. These results show that although chimpanzees are capable of spontaneous cooperation in a novel instrumental task, tolerance acts as a constraint on their ability to solve such cooperative problems. This finding highlights the importance of controlling such social constraints in future experiments on chimpanzee cooperation, and suggests that the evolution of human-like cooperative skills might have been preceded by the evolution of a more egalitarian social system and a more human-like temperament.
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Hansen, M. N., Estvan, J., & Ladewig, J. (2007). A note on resting behaviour in horses kept on pasture: Rolling prior to getting up. Appl. Anim. Behav. Sci., 105(1-3), 265–269.
Abstract: In previous studies on lying behaviour in horses kept in individual boxes we observed that most horses that had been lying down resting sometimes made a rolling behaviour prior to getting up. The rolling behaviour was seen in approximately 30% of the times the horses stood up. To analyse whether the behaviour was caused by individual housing in a box or whether it is a behaviour occurring also under free range conditions, we observed a group of 43 horses kept on pasture throughout the day and night. The horses were observed from 03:00 to 10:00 h over four consecutive mornings, at a time when lying behaviour was frequent. Of the 43 horses observed, the rising procedure was seen in 41 horses, and 25 of these horses (60.9%) performed the rolling behaviour at least once. A total of 135 rising episodes were observed, and 41 followed the performance of a rolling behaviour (30.4%). In contrast to the rolling behaviour seen indoors, the behaviour was more varied outdoors in that some horses rolled anywhere from 45 to 180[degree sign], some even repeatedly, whereas horses in a box only rolled 90[degree sign] and back. In all cases when horses rolled 180[degree sign] they rolled back to the original side before getting up. Also in contrast to previous observations, no horse was observed changing position during the roll. We conclude that the behaviour is a kind of comfort behaviour but that further studies are necessary to explain its function.
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Martin, T. I., Zentall, T. R., & Lawrence, L. (2006). Simple discrimination reversals in the domestic horse (Equus caballus): Effect of discriminative stimulus modality on learning to learn. Appl. Anim. Behav. Sci., 101(3-4), 328–338.
Abstract: The cognitive capacity of an organism, relative to that of other species, can be assessed by using a relative measure of learning. One such measure is the ability of an organism to learn about the reversal of a discrimination. The present study compared the performance of two groups of horses on a simple discrimination reversal task when the only difference between the groups was the modality of the relevant cue. For the visual group (absence or presence of a light), the spatial position was irrelevant. For the spatial group, a spatial cue (left/right) was available and the visual cue was irrelevant. Horses in the spatial group learned the original discrimination and six reversals; they also showed evidence of learning to learn. Horses in the visual group did not reach criterion during the study. As a result, there was no evidence of learning to learn.
Keywords: Horse; Learning-to-learn; Discrimination Reversal
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Heitor, F., do Mar Oom, M., & Vicente, L. (2006). Social relationships in a herd of Sorraia horses Part I. Correlates of social dominance and contexts of aggression. Behav. Process., 73(2), 170–177.
Abstract: Factors related to dominance rank and the functions of aggression were studied in a herd of Sorraia horses, Equus caballus, under extensive management. Subjects were 10 adult mares 5-18 years old and a stallion introduced into the group for breeding. Dominance relationships among mares were clear, irrespective of rank difference, and remained stable after introduction of the stallion. The dominance hierarchy was significantly linear and rank was positively correlated with age and total aggressiveness. Higher-ranking mares received lower frequency and intensity of agonistic interactions. Nevertheless, higher-ranking dominants were not more likely to elicit submission from their subordinates than lower-ranking dominants. Neither close-ranking mares nor mares with less clear dominance relationships were more aggressive towards each other. Agonistic interactions seemed to be used more importantly in regulation of space than to obtain access to food or to reassert dominance relationships. Contexts of aggression were related to mare rank. The results suggest that dominance relationships based on age as a conventional criterion were established to reduce aggressiveness in a herd where the costs of aggression are likely to outweigh the benefits.
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McGregor, A., Saggerson, A., Pearce, J., & Heyes, C. (2006). Blind imitation in pigeons, Columba livia. Anim. Behav., 72(2), 287–296.
Abstract: Pigeons that had been trained with a food reward both to peck at and to step on a horizontal plate were allowed to observe a conspecific demonstrator pecking at or stepping on the plate before a test in which the observers were not rewarded for either pecking or stepping. In experiment 1, the demonstrators were not rewarded while being observed. In spite of this, the observers provided evidence of imitation: those that had observed pecking made a greater proportion of pecking responses on test than observers of stepping. In experiment 2, each observer was exposed to a pecking or a stepping conspecific on two occasions. On one occasion, the demonstrator received a food reward for each demonstrated response (continuous reinforcement condition), and on the other the demonstrator's responses were rewarded only rarely (variable interval condition). The observers provided equally strong evidence of imitation in each of these conditions; on test, they made proportionally more of the observed response both when the demonstrators had been richly rewarded and when they had been rarely rewarded. These results show that pigeons engage in `blind' imitation, that is, their imitative behaviour is not always guided by observational learning about response outcomes.
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McBride, S. D., & Wolf, B. (2007). Using multivariate statistical analysis to measure ovine temperament; stability of factor construction over time and between groups of animals. Appl. Anim. Behav. Sci., 103(1-2), 45–58.
Abstract: The ovine arena test in conjunction with multivariate statistical analysis (factor analysis) may be a means of measuring ovine temperament for practical purposes. Stability of factor construction over time and between groups of animals is considered to demonstrate trait consistency and is, therefore, one of the first steps in validating a temperament/personality test from this perspective. The aim of this study, therefore, was to assess the stability of factor construction, as a measure of trait consistency, using arena test data from three groups of animals with one group (Group 1) tested repeatedly over three rounds (twice at 8 months and once at 22 months of age). Group 1 consisted of 193 mule (Bluefaced Leicester Sire x Scottish Blackface/Welsh Speckled Face dam), ewe lambs (8 months old). Groups 2 and 3 consisted of 189 and 185 mules, respectively (14 months old). All animals were tested for 6 min in a 13 m x 3 m arena. Factor analysis (varimax rotation) was performed twice on the behavioural data (latency to bleat, total number of vocalisations, distance travelled, time spent in different areas of the arena and number of times crossing in and out of pertinent areas), initially using all data recorded on a per minute basis (`Per Minute') for all 6 min of the test (10 factors extracted) and then using total values (`Total'), the summation of the 6 min for each behaviour measured (4 factors extracted). Stability of factor loadings between rounds and between groups was tested using Kendall's coefficient of concordance. For the `Per Minute' data, 5 out of the 10 factors showed significant (p < 0.05) concordance between rounds whilst 9 out of 10 factors showed significant (p < 0.05) concordance between groups. All four factors generated from the `Total' data demonstrated significant (p < 0.05) concordance between rounds and between groups. The four factors generated from the `Total' data were considered to be of potential merit for future studies. These factors were named--`conspecific motivation-fear', `conspecific motivation-distress', `activity' and `low conspecific motivation'.
Keywords: Arena test; Factor analysis; Temperament; Sheep
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