Langen, T. A. (1999). How western scrub-jays (Aphelocoma californica) select a nut: effects of the number of options, variation in nut size, and social competition among foragers. Anim. Cogn., 2(4), 223–233.
Abstract: Western scrub-jays (Aphelocoma californica) often visually assess and handle several whole (unshelled) peanuts before selecting one to transport and cache; this behavior is a search for a preferred heavy nut. I repeatedly video-taped individually identifiable jays as they landed on a feeding platform and chose from presentations of peanuts that varied in the number of items or in the distribution of sizes. I examined how differences among these presentations and a bird's social status affected the amount of assessment and the economic consequences of choice. I also examined the specific patterns of handling peanuts, called sampling, to quantify the degree to which sampling sequences were typified by repeated comparisons among sampled peanuts (retrospective sampling), or sequential assessment and rejection of peanuts (prospective sampling). Peanut assessment was more extensive and prospective when there were many options from which to choose than when there were few. Peanut assessment was more extensive and retrospective when options were similar in size than when they varied. Scrub-jays were more likely to make repeated comparisons immediately before selecting a peanut than elsewhere in a sampling sequence. Subordinate scrub-jays, who were at the greatest risk of pre-emption by competitors, assessed peanuts less extensively and were more prospective in their sampling than dominants. Unless peanuts were very similar in size, jays were more accurate at selecting a high-quality peanut and achieved a higher rate of food storage than if they had not assessed. These results show that scrub-jays can adaptively modify how they search to improve their rate of food storage, and also suggest some of the specific search tactics used by jays when assessing peanuts.
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Weed M.R., Taffe M.A., Polis I., Roberts A.C., Robbins T.W., Koob G.F., et al. (1999). Performance norms for a rhesus monkey neuropsychological testing battery: acquisition and long-term performance. Cognitive Brain Research, 8, 185–201.
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Vallortigara G., Regolin L., & Pagni P. (1999). Detour behaviour, imprinting and visual lateralization in the domestic chick. Cognitive Brain Research, 7, 307–320.
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Thomas R. Zentall. (1999). Animal Cognition: The Bridge BetweenAnimal Learning and Human Cognition. Psychological Science, 10, 206–208.
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Mullin, M. H. (1999). MIRRORS AND WINDOWS: Sociocultural Studies of Human-Animal Relationships. Annual Review of Anthropology, 28(1), 201–224.
Abstract: Humans' relationships with animals, increasingly the subject of controversy, have long been of interest to those whose primary aim has been the better understanding of humans' relationships with other humans. Since this topic was last reviewed here, human-animal relationships have undergone considerable reexamination, reflecting key trends in the history of social analysis, including concerns with connections between anthropology and colonialism and with the construction of race, class, and gender identities. There have been many attempts to integrate structuralist or symbolic approaches with those focused on environmental, political, and economic dimensions. Human-animal relationships are now much more likely to be considered in dynamic terms, and consequently, there has been much interdisciplinary exchange between anthropologists and historians. Some research directly engages moral and political concerns about animals, but it is likely that sociocultural research on human-animal relationships will continue to be as much, if not more, about humans.
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Rogers, C. W., Davies, A. S., Pfeiffer, D. U., & Davie, P. S. (1999). Linear and temporal stride characteristics of 3-day event horses at a CCI*** 3-day event horse inspection. N Z Vet J, 47(6), 193–197.
Abstract: AIMS: To quantify the linear and temporal characteristics of the trot of 3-day event horses during the preliminary horse inspection of an advanced grade CCI* 3-day event. METHODS: A cross sectional study was made of the kinematics of 24 3-day-event horses during the first horse inspection at a CCI* level S-day event. Video footage was digitised and linear and temporal measurements were made. RESULTS: The horses trotted for an average of 10.44+/-1.55 strides. Spatial measurements were made on an average of 5.66+/-0.92 consecutive strides when the horses were within the calibration zone. The horses increased and then obtained a constant velocity within the calibration zone. Trotting on the asphalt track did not alter the relationships between stride length, stride duration and velocity when compared with previously published values. Horse-specific differences in stance and retraction percentages were identified. CONCLUSION: Horse specific differences were identified that may contribute to each horse's unique gait or kinematic fingerprint. It is proposed that the initiation of, and completion of, stance by the hind limb first may represent engagement of the hind quarters and be a response to dressage training.
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Gough, M. R. (1999). A note on the use of behavioural modification to aid clipping ponies. Appl. Anim. Behav. Sci., 63(2), 171–175.
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Mills, D. S., & Nankervis, K. J. (1999).
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Mladenoff, D. J., Sickley, T. A., & Wydeven, A. P. (1999). Predicting gray wolf landscape recolonization: logistic regression models vs. new field data. Ecol Appl, 9.
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Call, J., Aureli, F., & de Waal, F. B. M. (1999). Reconciliation patterns among stumptailed macaques: a multivariate approach. Anim. Behav., 58(1), 165–172.
Abstract: This study focused on two aspects of the dynamics of reconciliation in stumptailed macaques, Macaca arctoides. First, we investigated the combined effects of multiple variables (i.e. sex, age, rank, conflict intensity, outcome, or number of participants, interopponent distance, kinship and friendship) on the occurrence of reconciliation. Second, we investigated whether opponents used different behaviour patterns in their postconflict reunions depending on the characteristics of their conflicts or their relationship with their opponents. We studied a multimale, multifemale group of 38 stumptailed macaques housed in a large outdoor compound. Three types of data were collected: (1) instantaneous scan sampling of contact sitting to infer 'friendship'; (2) ad libitum data on bared-teeth and teeth-chattering displays to infer dominance rank; (3) 10-min focal observations during postconflict (PC) and matched control (MC) periods in which we recorded interopponent distance at the beginning of the observation and all aggressive and affiliative behaviours between former opponents. Our study confirmed the high conciliatory tendency of stumptailed macaques previously reported for other groups. A stepwise logistic regression revealed that initial interopponent distance in PC, friendship and kinship were the only factors that independently contributed to explain the occurrence of reconciliation. Two main clusters of postconflict behavioural patterns emerged: allogrooming+contact sitting and sociosexual behaviours (e.g. hold-bottom). It is hypothesized that postconflict allogrooming and contact sitting may be used for the maintenance of valuable relationships, whereas sociosexual behaviours may be used more indiscriminately by any pair of opponents as a buffering mechanism to prevent immediate recurrence of aggression. Copyright 1999 The Association for the Study of Animal Behaviour.
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