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Wilson, D. S., & Dugatkin, L. A. (1996). A reply to Lombardi & Hurlbert. Anim. Behav., 52(2), 423–425.
Abstract: No abstract
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Galef, B. G. (1996). The adaptive value of social learning: a reply to Laland. Anim. Behav., 52(3), 641–644.
Abstract: No abstract
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Schwarzenberger, F., Mostl, E., Palme, R., & Bamberg, E. (1996). Faecal steroid analysis for non-invasive monitoring of reproductive status in farm, wild and zoo animals. Animal Reproduction: Research and Practice, 42(1-4), 515–526.
Abstract: Non-invasive faecal oestrogen and progesterone metabolite evaluations are well established approaches for monitoring reproductive function in a variety of mammalian species. The route of excretion of steroid hormone metabolites varies considerably among species, and also between steroids within the same species. Steroid concentrations in faeces exhibit a similar pattern to those in plasma, but have a lag time, which depending upon the species, can be from 12 h to more than 2 days. Faecal steroid metabolites in mammals are mainly unconjugated compounds. Faecal oestrogens consist predominantly of oestrone and/or oestradiol-17α or -17β. Therefore, specific oestrogen antibodies or antibodies against total oestrogens can be used for their determination. Progesterone is metabolised to several 5α- or 5β-reduced pregnanediones and hydroxylated pregnanes prior to its faecal excretion. Therefore, relevant antibodies for their determination show considerable cross-reactivities with several pregnane metabolites, whereas specific progesterone antibodies are less suitable. Faecal oestrogen evaluations have been used as reliable indicators of pregnancy in several ungulate and some primate species. They have also been used to determine the preovulatory period in carnivores, corpus luteum activity in New World primates, and to diagnose cryptorchidism in horses. Faecal progesterone metabolite analysis has been successfully used for monitoring corpus luteum function and pregnancy, abortion, seasonality and treatment therapies in an ever expanding list of species.
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Atwill, E. R., Mohammed, H. O., & Lopez, J. W. (1996). Evaluation of travel and use as a risk factor for seropositivity to Ehrlichia risticii in horses of New York state. Am J Vet Res, 57(3), 272–277.
Abstract: OBJECTIVES--To determine whether mean annual frequency and destination of equine travel was associated with exposure to Ehrlichia risticii and whether these associations were modified by horses' place of residence. DESIGN--Cross-sectional study. SAMPLE POPULATION--511 equine operations containing 2,587 horses were visited in New York state from a target population of 39,000 operations. PROCEDURE--Each horse was tested for serum antibodies against E risticii, using indirect fluorescent antibody. Information on the horse's travel history, farm's management practices, and surrounding ecology was obtained by personal interview and resource maps. Statistical analyses were performed on 2 cohorts of animals: all horses enrolled in the study and horses born on the property or that resided at least 4 years on the farm. Three county-based risk regions (RR) were identified by use of cluster analysis. RESULTS--Mean seroprevalence for each of the 3 RR was 2.4 (low risk), 8.5 (moderate risk), and 18.5% (high risk) for cohort 1 and 2.5, 8.0, and 18.4% for cohort 2. Among cohorts 1 and 2, pleasure riding and breeding trips were associated with exposure to E risticii, but horse residence (low, moderate, or high RR) was an effect modifier for these associations. Among cohort 1 and stratifying the analysis according to the RR for the travel destination, trail riding at low RR and trail riding at high RR were associated with exposure. Among cohort 2 and stratifying the analysis according to the RR for the travel destination, breeding trips were associated with exposure, and strong effect modification was present for horse residence (low, moderate, or high RR). CONCLUSIONS--Only certain types of travel to specific RR were associated with higher risk of exposure to E risticii. In many instances, travel was not associated, or was associated, with a reduced risk of exposure.
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Whiten, A., Custance, D. M., Gomez, J. C., Teixidor, P., & Bard, K. A. (1996). Imitative learning of artificial fruit processing in children (Homo sapiens) and chimpanzees (Pan troglodytes). J Comp Psychol, 110(1), 3–14.
Abstract: Observational learning in chimpanzees and young children was investigated using an artificial fruit designed as an analog of natural foraging problems faced by primates. Each of 3 principal components could be removed in 2 alternative ways, demonstration of only one of which was watched by each subject. This permitted subsequent imitation by subjects to be distinguished from stimulus enhancement. Children aged 2-4 years evidenced imitation for 2 components, but also achieved demonstrated outcomes through their own techniques. Chimpanzees relied even more on their own techniques, but they did imitate elements of 1 component of the task. To our knowledge, this is the first experimental evidence of chimpanzee imitation in a functional task designed to simulate foraging behavior hypothesized to be transmitted culturally in the wild.
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Sekuler, A. B., Lee, J. A., & Shettleworth, S. J. (1996). Pigeons do not complete partly occluded figures. Perception, 25(9), 1109–1120.
Abstract: One of the most common obstacles to object perception is the fact that objects often occlude parts of themselves and parts of other objects. Perceptual completion has been studied extensively in humans, and researchers have shown that humans do complete partly occluded objects. In an effort to understand more about the mechanisms underlying completion, recent research has extended the study of perceptual completion to other mammalian species. Monkeys and mice also seem to complete two-dimensional representations of partly occluded objects. The present study addresses the question of whether this capacity generalizes to a nonmammalian species, the pigeon (Columba livia). The results point to a limit of the generalizability of perceptual completion: pigeons do not complete partly occluded figures.
Keywords: Animals; *Columbidae; *Visual Perception
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Kaseda, Y., & Khalil, A. M. (1996). Harem size and reproductive success of stallions in Misaki feral horses. Appl. Anim. Behav. Sci., 47(3-4), 163–173.
Abstract: Over a 16-year period (1979-1994), long-term investigations were carried out on 14 Misaki feral stallions to analyze changes in harem size and the reproductive success. Harem size changed with the age of the stallions. Most stallions formed harem groups with four to five mares at the age of 4-6 and then the number of mares increased rapidly to the maximum at the age of 6-9 years. Thereafter, harem size decreased gradually to a minimum with advancing age. The harem size of 60 stable harem groups ranged from 1 to 9, and the average varied from a minimum mean of 1.8 in 1988 to a maximum mean of 5.3 in 1982. Mean harem size increased as adult sex ratio increased and a significant and positive correlation was found between them. One hundred and ninety-eight sire-foal pairs were determined by a paternity test with blood types and consort relations between stallions and mares during the study period. Out of 99 foals which were born in the stable harem groups, the true sires of 84 foals (85%) were the harem stallions in which the foals were born but the remaining 15 foals (15%) were sired by other harem stallions. Two out of three stallions which were studied throughout their lifetime produced 24 and 25 foals in 10 and 11 years of their reproductive lifespan, respectively. Another one produced only five foals in 6 years. The number of foals sired by the harem stallions was less than two over harem size 7 and some of the foals born in the harem were sired by other harem stallions. These results suggest that if a particular stallion monopolizes too many mares, he could not sire so many offspring because he could not always prevent his rival stallions from mating with his mares in wild or feral circumstances.
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Barton, R. A., Byrne, R. W., & Whiten, A. (1996). Ecology, feeding competition and social structure in baboons. Behav. Ecol. Sociobiol., 38(5), 321–329.
Abstract: Predictions of the model of van Schaik (1989) of female-bonding in primates are tested by systematically comparing the ecology, level of within-group contest competition for food (WGC), and patterns of social behaviour found in two contrasting baboon populations. Significant differences were found in food distribution (percentage of the diet from clumped sources), feeding supplant rates and grooming patterns. In accord with the model, the tendencies of females to affiliate and form coalitions with one another, and to be philopatric, were strongest where ecological conditions promoted WGC. Group fission in the population with strong WGC was “horizontal” with respect to female dominance rank, and associated with female-female aggression during a period of elevated feeding competition. In contrast, where WGC was low, females' grooming was focused on adult males rather than other females. Recent evidence suggests that group fission here is initiated by males, tends to result in the formation of one-male groups, and is not related to feeding competition but to male-male competition for mates. An ecological model of baboon social structure is presented which incorporates the effects of female-female competition, male-male competition, and predation pressure. The model potentially accounts for wide variability in group size, group structure and social relationships within the genus Papio. Socio-ecological convergence between common baboons and hamadryas baboons, however, may be limited in some respects by phylogenetic inertia.
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Treichler, F. R., & Van Tilburg, D. (1996). Concurrent Conditional Discrimination Tests of Transitive Inference by Macaque Monkeys: List Linking. J Exp Psychol Anim Behav Process, 22(1), 105–117.
Abstract: Processing of serial information was assessed by training six macaques on a five-item list of objects arranged into the four conditional pairs, A-B+, B-C+, C-D+, and D-E+. An analogous list (F through J) was similarly trained. Subsequently, both lists were linked by training on E-F+, a pair that provided adjacent elements from each list. Then, all unique and trained object pairs from both lists were presented as a test. Results indicated that the objects were retained as a single, linearly organized list with choice accuracy directly related to interitem distance between paired objects. A second experiment explored the consequences of incidence of conflicting information on list organization. In both experiments, selections depended on representational processes and supported the view that monkeys and pigeons retain serial lists in qualitatively different ways.
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Davis, M. H. (1996). Empathy: A Social Psychological Approach. Boulder, CO: Westview Press.
Abstract: Product Description
Empathy has long been a topic of interest to psychologists, but it has been studied in a sometimes bewildering number of ways. In this volume, Mark Davis offers a thorough, evenhanded review of contemporary empathy research, especially work that has been carried out by social and personality psychologists.Davis’ approach is explicitly multidimensional. He draws careful distinctions between situational and dispositional “antecedents” of empathy, cognitive and noncognitive “internal processes,” affective and nonaffective “intrapersonal outcomes,” and the “interpersonal behaviora l outcomes” that follow. Davis presents a novel organizational model to help classify and interpret previous findings. This book will be of value in advanced undergraduate and graduate courses on altruism, helping, nad moral development. About the Author Mark H. Davis is associate professor of psychology at Eckerd College in St. Petersburg, Florida. |