Hedrick, P. W., Parker, K. M., Miller, E. L., & Miller, P. S. (1999). Major Histocompatibility Complex Variation in the Endangered Przewalski's Horse. Genetics, 152(4), 1701–1710.
Abstract: The major histocompatibility complex (MHC) is a fundamental part of the vertebrate immune system, and the high variability in many MHC genes is thought to play an essential role in recognition of parasites. The Przewalski's horse is extinct in the wild and all the living individuals descend from 13 founders, most of whom were captured around the turn of the century. One of the primary genetic concerns in endangered species is whether they have ample adaptive variation to respond to novel selective factors. In examining 14 Przewalski's horses that are broadly representative of the living animals, we found six different class II DRB major histocompatibility sequences. The sequences showed extensive nonsynonymous variation, concentrated in the putative antigen-binding sites, and little synonymous variation. Individuals had from two to four sequences as determined by single-stranded conformation polymorphism (SSCP) analysis. On the basis of the SSCP data, phylogenetic analysis of the nucleotide sequences, and segregation in a family group, we conclude that four of these sequences are from one gene (although one sequence codes for a nonfunctional allele because it contains a stop codon) and two other sequences are from another gene. The position of the stop codon is at the same amino-acid position as in a closely related sequence from the domestic horse. Because other organisms have extensive variation at homologous loci, the Przewalski's horse may have quite low variation in this important adaptive region. N1 -
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Erhart, E., & Overdorff, D. (1999). Female Coordination of Group Travel in Wild Propithecus and Eulemur. Int. J. Primatol., 20(6), 927-940.
Abstract: Coordination of primate group movements by individual group members is generally categorized as leadership behavior, which entails several steps: deciding where to move next, initiating travel, and leading a group between food, water sources, and rest sites. Presumably, leaders are able to influence their daily foraging efficiency and nutritional intake, which could influence an individual's feeding ecology and long-term reproductive success. Within anthropoid species, females lead group movements in most female-bonded groups, while males lead groups in most nonfemale-bonded groups. Group leadership has not been described for social prosimians, which are typically not female-bonded. We describe group movements in two nonfemale-bonded, lemurid species living in southeastern Madagascar, Propithecus diadema edwardsi and Eulemur fulvus rufus. Although several social lemurids exhibit female dominance Eulemur fulvus rufus does not, and evidence for female dominance is equivocal in Propithecus diadema edwardsi. Given the ecological stresses that females face during reproduction, we predict that females in these two species will implement alternative behavioral strategies such as group leadership in conjunction with, or in the absence of, dominance interactions to improve access to food. We found that females in both species initiated and led group movements significantly more often than males did. In groups with multiple females, one female was primarily responsible for initiating and leading group movements. We conclude that female nutritional needs may determine ranging behavior to a large extent in these prosimian species, at least during months of gestation and lactation.
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Hopster, H., van der Werf, J. T., Erkens, J. H., & Blokhuis, H. J. (1999). Effects of repeated jugular puncture on plasma cortisol concentrations in loose-housed dairy cows. J Anim. Sci, 77(3), 708–714.
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Powell, D. M. (1999). Preliminary evaluation of porcine zona pellucida (PZP) immunocontraception for behavioral effects in feral horses (Equus caballus). J Appl Anim Welf Sci, 2(4), 321–335.
Abstract: Successful management of captive populations of wild animals requires effective control of reproduction. Contraception is one tool for controlling reproduction of animals in zoos; however, the options available to the animal manager are limited. Contraceptives vary in efficacy, reversibility, and side effects, and thus may not be suitable for widespread use. One consideration when selecting a contraceptive is its potential for side effects on behavior, especially given the fact that reproduction plays such a prominent role in the biology of any species. To date, there have been few evaluations of contraceptives for behavioral effects, and those that have been conducted have focused on hormone-based contraceptives. This study sought to evaluate a novel method of population control, immunocontraception, for behavioral effects in a population of feral horses. Porcine zona pellucida (PZP) immunocontraception prevents fertilization of ova and does not alter normal hormone secretion patterns. It therefore should leave the animal behaviorally intact in terms of reproductive behavior. The study examined the behavior of 43 sexually mature mares on Assateague Island during the 1997 breeding season and, with help from Earthwatch volunteers, collected observations over a 3-month period. The study found no significant differences between treated and untreated mares in general activity budget, aggression given or received, and spatial relationships relative to the stallion. These preliminary findings indicate that PZP contraception seems to have no acute behavioral effects on the behavior of individuals. The study findings also suggest that PZP could be a desirable and effective management tool for captive species in which social behavior plays an integral role in group dynamics. Analyses of group level effects and population level effects are continuing.
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Lilienfeld, S. O., Gershon, J., Duke, M., Marino, L., & de Waal, F. B. (1999). A preliminary investigation of the construct of psychopathic personality (psychopathy) in chimpanzees (Pan troglodytes). J Comp Psychol, 113(4), 365–375.
Abstract: Although the construct of psychopathy has received considerable attention in humans, its relevance to other animals is largely unknown. We developed a measure of psychopathy for use in chimpanzees (Pan troglodytes), the Chimpanzee Psychopathy Measure (CPM), and asked 6 raters to complete this index on 34 chimpanzees. The CPM (a) demonstrated satisfactory interrater reliability and internal consistency; (b) exhibited marginally significant sex differences (males > females); (c) correlated positively with measures of extraversion, agreeableness, and observational ratings of agonism, sexual activity, daring behaviors, teasing, silent bluff displays, and temper tantrums, and negatively with observational ratings of generosity; and (d) demonstrated incremental validity above and beyond a measure of dominance. Although further validation of the CPM is needed, these findings suggest that the psychopathy construct may be relevant to chimpanzees.
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Aureli, F., Preston, S. D., & de Waal, F. B. (1999). Heart rate responses to social interactions in free-moving rhesus macaques (Macaca mulatta): a pilot study. J Comp Psychol, 113(1), 59–65.
Abstract: Heart rate telemetry was explored as a means to access animal emotion during social interactions under naturalistic conditions. Heart rates of 2 middle-ranking adult females living in a large group of rhesus macaques (Macaca mulatta) were recorded along with their behavior. Heart rate changes during 2 types of interactions were investigated, while controlling for the effects of posture and activity. The risk of aggression associated with the approach of a dominant individual was expected to provoke anxiety in the approachee. This prediction was supported by the heart rate increase after such an approach. No increase was found when the approacher was a kin or a subordinate individual. The tension-reduction function of allogrooming was also supported. Heart rate decelerated faster during the receipt of grooming than in matched control periods.
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Hanggi, E. B. (1999). Interocular transfer of learning In horses (Equus caballus). J Equine Vet Sci, 19(8), 518–524.
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Zentall, T. R. (1999). Support for a theory of memory for event duration must distinguish between test-trial ambiguity and actual memory loss. J Exp Anal Behav, 72(3), 467–472.
Abstract: Staddon and Higa's (1999) trace-strength theory of timing and memory for event duration can account for pigeons' bias to “choose short” when retention intervals are introduced and to “choose long” when, following training with a fixed retention interval, retention intervals are shortened. However, it does not account for the failure of pigeons to choose short when the intertrial interval is distinct from the retention interval. That finding suggests that stimulus generalization (or ambiguity) between the intertrial interval and the retention interval may result in an effect that has been attributed to memory loss. Such artifacts must be eliminated before a theory of memory for event duration can be adequately tested.
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Farmer-Dougan, V., & Dougan, J. (1999). The Man Who Listens To Behavior: Folk Wisdom And Behavior Analysis From A Real Horse Whisperer. J Exp Anal Behav, 72(1), 139–149.
Abstract: The popular novel and movie The Horse Whisperer are based on the work of several real-life horse
whisperers, the most famous of whom is Monty Roberts. Over the last 50 years, Roberts has developed
a technique for training horses that is both more effective and less aversive than traditional training
techniques. An analysis of Roberts` methods (as described in his book, The Man Who Listens to Horses)
indicates a deep understanding of behavioral principles including positive reinforcement, timeout,
species-specific defense reactions, learned helplessness, and the behavioral analysis of language.
Roberts developed his theory and techniques on the basis of personal experience and folk wisdom,
and not as the result of formal training in behavior analysis. Behavior analysts can clearly learn from
such insightful yet behaviorally incorrect practitioners, just as such practitioners can benefit from
the objective science of behavior analysts.
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Crystal, J. D. (1999). Systematic nonlinearities in the perception of temporal intervals. J Exp Psychol Anim Behav Process, 25(1), 3–17.
Abstract: Rats judged time intervals in a choice procedure in which accuracy was maintained at approximately 75% correct. Sensitivity to time (d') was approximately constant for short durations 2.0-32.0 s with 1.0- or 2.0-s spacing between intervals (n = 5 in each group, Experiment 1), 2.0-50.0 s with 2.0-s spacing (n = 2, Experiment 1), and 0.1-2.0 s with 0.1- or 0.2-s spacing (n = 6 in each group, Experiment 2). However, systematic departures from average sensitivity were observed, with local maxima in sensitivity at approximately 0.3, 1.2, 10.0, 24.0, and 36.0 s. Such systematic departures from an approximately constant d' are predicted by a connectionist theory of time with multiple oscillators and may require a modification of the linear timing hypothesis of scalar timing theory.
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