Westlin-van Aarde, L. M., van Aarde, R. J., & Skinner, J. D. (1988). Reproduction in female Hartmann's zebra. J Reprod Fert, 84, 505–511.
Abstract: Ovaries, fetuses and plasma were collected from zebra mares shot in the Etosha National Park in Namibia between 15 and 25 August 1983. Ovarian weight was affected by reproductive status and most of the non-pregnant mares were anoestrous. The number of follicles varied between individuals and only pro-oestrous/oestrous mares had follicles larger than 20 mm in diameter. The largest follicle in pregnant mares was only 9 mm in diameter. Corpora lutea and corpora albicantia were found in non-pregnant as well as pregnant mares: 4 pregnant mares had only corpora albicantia. The presence of secondary corpora lutea could not be confirmed in any of the pregnant mares. Implantation was estimated to occur at around 73 days of gestation, and most mares (84%) had conceived between November and April. Peripheral concentrations of plasma progesterone during pregnancy varied from 0·5 to 2·4 ng/ml.
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Berger, J.,. (1988). Social systems, resources, and phylogenetic inertia: an experimental test and its limitations. In C. N. Slobochikoff (Ed.), Ecology of Social Behavior (pp. 157–186). San Diego: Academic Press.
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Byrne, R., & Whiten, A. (1988). Machiavellian Intelligence. Oxford: Oxford Univ Press.
Abstract: This book presents an alternative to conventional ideas about the evolution of the human intellect. Instead of placing top priority on the role of tools, the pressure for their skillful use, and the related importance of interpersonal communication as a means for enhanced cooperation, this<BR>volume explores quite a different idea-- that the driving force in the evolution of human intellect was social expertise--a force which enabled the manipulation of others within the social group, who themselves are seen as posing the most challenging problems faced by primitive humans. The need to<BR>outwit one's clever colleagues then produces an evolutionary spiraling of “Machiavellian intelligence.” The book forms a complete and self-contained text on this fast-growing topic. It includes the origins of the basic premise and a wealth of exciting developments, described by an international<BR>team of authors from the fields of anthropology, psychology, and zoology. An evaluation of more traditional approaches is also undertaken, with a view to discovering to what extent Machiavellian intelligence represents a complementary concept or one that is truly an alternative. Readers and<BR>students will find this fascinating volume carries them to the frontiers of scientific work on the origin of human intellect.
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Byrne, R., & Whiten, A. (1988). The machiavellian intelligence hypothesis:Editorial. In Machiavellian Intelligence (pp. 1–9). Oxford: Oxford Univ Press.
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Hauser M.D. (1988). Invention and social transmission: new data from wild vervet monkeys. In Machiavellian Intelligence (pp. 327–343). Oxford: Oxford Univ Press.
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Cheney, D. L., & Seyfarth, R. M. (1988). Social and non.social knowledge in vervet monkeys. In Machiavellian Intelligence (pp. 255–270). Oxford: Oxford Univ Press.
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Dasser V. (1988). Mapping social concepts in monkeys. In Machiavellian Intelligence (pp. 85–93). Oxford: Oxford Univ Press.
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Hayes, K. (1988). Temperament tip-offs. Horse and Rider, 11, 47–84.
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Clutton-Brock, T. H., Green, D., Hiraiwa-Hasegawa, M., & Albon, S. D. (1988). Passing the buck: resource defence, lek breeding and mate choice in fallow deer. Behav. Ecol. Sociobiol., 23, 281–296.
Abstract: lsquoLekrsquo breeding systems, where males defend small, clustered mating territories, are thought to occur where the distribution of females is heavily clumped but males are unable to defend resources used by females. In this paper, we describe a breeding system in fallow deer where males are able to defend resources used by females but the most successful bucks instead defend small territories on a traditional mating ground; where the lek is sited in an area not heavily used by females at other times of year and is visited primarily by females in or close to oestrus; and where mating success on the lek is related to territory position and to male phenotype but not to the resources available on different lek territories. Comparisons with other ungulates suggest that lek breeding species fall into two groups: those where leks are regularly visited by herds of females many of which are not in oestrus and those, like fallow deer, where leks are visited primarily by oestrous females. In the latter species, it is unlikely that females visit the lek for ecological reasons.
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Leonard, M. L., Horn, A. G., & Eden, S. F. (1988). Parent-offspring aggression in moorhens. Behav. Ecol. Sociobiol., 23, 265–270.
Abstract: The purpose of this study was to explain parental aggression to offspring in the moorhen (Gallinula chloropus). Males and females did not feed different subsets of chicks. In addition, there was a positive correlation between feeding rates of each parent to a particular chick and the number of attacks (tousles) directed to that chick, contrary to what was expected if aggression served to divide the brood. In moorhens, large chicks outcompeted small chicks for parental feedings. However, adults were more aggressive to large chicks and as a result small chicks spent significantly more time closer to parents and received more feedings than large chicks. In 84% of broods every chick was attacked at least once, although large chicks were attacked more often than small chicks. The behaviour of chicks changed immediately after an attack (Table 2). Before an attack chicks were <1 m from the parents while after an attack they were >1 m. The apparent effect of parental aggression in moorhens is to reduce demands by chicks for feedings. Aggression appears to reduce sibling competition and to encourage chick independence.
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