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Dunbar, R. I., & Dunbar, E. P. (1976). Contrasts in social structure among black-and-white colobus monkey groups. Anim. Behav., 24(1), 84–92.
Abstract: Three types of Colobus guereza groups may be distinguished on the bases of size and composition, namely small one-male groups, large, one-male groups and multi-male groups. The social structure of each type of group is described in terms of the distribution of non-agonistic interactions, the frequency and distribution of agonistic behaviour and the organization of the roles of vigilance, territorial defence and leadership. A number of differences are found between the group types which appear to be related to the differences in group size and composition. It is suggested that these group types represent stages in the life-cycle of colobus groups, and that such an interpretation may help to resolve some of the conflicting reports in the literature.
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McGregor, P. K., & Dabelsteen, T. (1976). Communication Networks. In D. E. Kroodsma, & E. H. Miller (Eds.), Ecology and evolution of acoustic communication in birds (pp. 409–425). Ithaca: Cornell University Press.
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Clabby, J. (1976). The Natural History of the Horse. New York: Taplinger Publishing Company.
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Joubert, E., & Louw, G. N. (1976). Preliminary observations on the digestive and renal efficiency of Hartmann's zebra Equus zebra hartmannae. Madoqua, 10, 119–121.
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Feist, J. D., & McCullough, D. R. (1976). Behavior patterns and communication in feral horses. Z. Tierpsychol., 41(4), 337–371.
Abstract: The social behavior of feral horses was studied in the western United States. Stable harem groups with a dominant stallion and bachelor hermaphrodite hermaphrodite groups occupied overlapping home ranges. Groups spacing, but not territoriality, was expressed. Harem group, stability resulted from strong dominance by dominant stallions, and fidelity of group members. Eliminations of group members were usually marked by urine of the dominant stallion. Hermaphrodite-hermaphrodite aggression involved spacing between harems and dominance in bachelor groups. Marking with feces was important in hermaphrodite-hermaphrodite interactions. Foaling occurred in May and early June, following the post-partum estrous. All breeding was done by harem stallions. Young were commonly nursed through yearling age. These horses showed social organizations similar to other feral horses and plains zebras.
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Smith, J. M., & Parker, G. A. (1976). The logic of asymmetric contests. Anim. Behav., 24(1), 159–175.
Abstract: A theoretical analysis is made of the evolution of behavioural strategies in contest situations. It is assumed that behaviour will evolve so as to maximize individual fitness. If so, a population will evolve an [`]evolutionarily stable strategy', or ESS, which can be defined as a strategy such that, if all members of a population adopt it, no [`]mutant' strategy can do better. A number of simple models of contest situations are analysed from this point of view. It is concluded that in [`]symmetric' contests the ESS is likely to be a [`]mixed' strategy; that is, either the population will be genetically polymorphic or individuals will be behaviourally variable. Most real contests are probably asymmetric, either in pay-off to the contestants, or in size or weapons, or in some [`]uncorrelated' fashion; i.e. in a fashion which does not substantially bias either the pay-offs or the likely outcome of an escalated contest. An example of an uncorrelated asymmetry is that between the [`]discoverer' of a resource and a [`]late-comer'. It is shown that the ESS in asymmetric contests will usually be to permit the asymmetric cue to settle the contest without escalation. Escalated contests will, however, occur if information to the contestants about the asymmetry is imperfect.
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Schaller, G. B.:. (1976). The Serengeti Lion: A Study of Predator-Prey Relations (Wildlife Behavior and Ecology series). Chicago: University Of Chicago Press.
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Bernstein, I. S. (1976). Dominance, aggression and reproduction in primate societies. J. Theor. Biol., 60(2), 459–472.
Abstract: Dominance relationships in primate societies are generally inferred by analyses of agonistic interactions. This aspect of social organization is so striking in macaque and baboon societies that many theoreticians have postulated selective mechanisms operating on the genetic attributes which contribute to high dominance rank. Alpha males were hypothesized to increase their genetic fitness by successfully competing with other males for access to ovulating females. Evidence relevant to these speculations has been mixed. Whereas some investigators found alpha males had near exclusive sexual access to females, others failed to confirm preferential access to ovulating females. Indeed, considerable variability in competition for females existed not only among species, but also among troops of the same species living in different habitats. Further, partner selection was not an exclusive male prerogative; females proved to express active preferences for particular males as sexual partners, and these preferences were not related to high male aggressivity. Alpha males, however, were noted to maintain their positions through social skills as members of a central core or alliance, and high rank was related primarily to seniority. Moreover, alpha males responded actively to challenges to the troop and were judged to contribute significantly to the survival of infants. It was therefore hypothesized that increased genetic fitness related to the increased survival of immature animals in the troop, most of which would already be the offspring of senior (and hence alpha) males. Selection would then be for the social skills leading to successful alliances in troop defense. Such skills might also relate to female partner preferences thus increasing the reproductive effectiveness of alpha males at any point in their careers, including years prior to and following their assumption of alpha rank.
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Humphrey, N. K. (1976). The social function of intellect. In P. P. G. Bateson, & R. A. Hinde (Eds.), Growing Points in Ethology (pp. 303–317). Cambridge: Cambridge University Press.
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Ziegler, W. H. (1976). [Endocrinological studies in arterial hypertension. Search for phaeochromocytoma]. Schweiz Med Wochenschr, 106(34), 1148–1150.
Abstract: Elevated urinary catecholamines and their metabolites are the only findings which confirm the presence of pheochromocytoma. This examination is of particular interest if carried out in urine produced after spontaneous hypertensive episodes. Pharmacologic tests when carried out under standard conditions have proven to be a reliable aid in cases of suspected pheochromocytoma. Roentgenographic studies, determination of local plasma catecholamine concentrations and blood volume control should be undertaken in these patients before surgical procedure.
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