Stutz, W. A., Topliff, D. R., Freeman, D. W., Tucker, W. B., Breazile, J. W., & Wall, D. L. (1992). Effects of dietary cation-anion balance on blood parameters in exercising horses. Journal of Equine Veterinary Science, 12(3), 164–167.
Abstract: Summary Four geldings and four mares of primarily Thoroughbred and Quarter Horse breeding were used in simultaneous 4x4 Latin square experiments to test the effects of dietary cation-anion balance (DCAB), defined as meq ((Na+K)-C1)/kg diet dry matter, on blood pH, blood gases, acid-base status and plasma glucose in horses at rest and following anaerobic exercise. Four diets, consisting of a base concentrate of corn, soybean meal and cottonseed hulls fed in a 60:40 ratio with Bermudagrass hay, were formulated to provide a DCAB of 5 (L=Low), 107 (ML=Medium Low), 201 (MH=Medium High) and 327 (H=High) meq ((Na+K)-C1)/kg diet dry matter. Calcium chloride and ammonium chloride were added to treatment L and ML and sodium bicarbonate and potassium citrate were added to treatment H to achieve the desired cation-anion balance. Treatment MH was not supplemented and served as the control treatment. Prior to the experiment, horses performed six weeks of long, slow, distance (LSD) work. During the experimental periods, horses were subjected to an exercise regimen alternating LSD with an interval training protocol 6 days/week. Venous blood pH, pCO2 and bicarbonate levels were significantly lower in horses at rest consuming diet L versus diets MH and H. Blood pH and acid-base parameters decreased with decreasing DCAB. There were no significant differences in blood pH or acid-base parameters between treatments, after anaerobic exercise. Plasma glucose concentrations for treatment L were significantly lower than treatment H at 10, 20, and 30 minutes post-exercise. These data suggest that DCAB has significant effect on acid-base status and indicate that horses consuming diets with low DCAB may experience a metabolic acidosis.
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Nowak, M. A., & Sigmund, K. (1992). Tit for tat in heterogeneous populations. Nature, 355, 250–253.
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Dugatkin, L. A., Mesterton-Gibbons, M., & Houston, A. I. (1992). Beyond the prisoner's dilemma: Toward models to discriminate among mechanisms of cooperation in nature. Trends Evol. Ecol., 7, 202–205.
Abstract: The iterated prisoner's dilemma game, or IPD, has now established itself as the orthodox paradigm for theoretical investigations of the evolution of cooperation; but its scope is restricted to reciprocity, which is only one of three categories of cooperation among unrelated individuals. Even within that category, a cooperative encounter has in general three phases, and the IPD has nothing to say about two of them. To distinguish among mechanisms of cooperation in nature, future theoretical work on the evolution of cooperation must distance itself from economics and develop games as a refinement of ethology's comparative approach.
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Aureli, F., Cossolino, R., Cordischi, C., & Scucchi, S. (1992). Kin-oriented redirection among Japanese macaques: an expression of a revenge system? Anim. Behav., 44(2), 283–291.
Abstract: The ability to recognize the close associates of other group members may permit the display of redirected aggression against the relatives of the former aggressor. However, the dominance structure and the kin-based alliance system of macaque society are expected not to favour the occurrence of this kin-oriented redirection. Nevertheless, within 1 h of being the victim of an attack, Japanese macaques, Macaca fuscata, were more likely to attack the former aggressor's kin than without such a conflict. The conditions under which the victim redirected against the former aggressor's kin were investigated. This kin-oriented redirection did not occur preferentially either after conflicts between individuals with unstable and/or uncertain dominance relationships or after conflicts with individuals that were unlikely to intervene in favour of their kin. Victims redirected against individuals that were younger than the former aggressor and often subordinate to the victim. They also redirected in an opportunistic way by joining polyadic interactions against the former aggressor's kin. The possibility that this kin-oriented redirection may have a long-term function in changing the aggressive attitude of the aggressor towards the victim is also discussed. In addition, the victim's kin also displayed a form of kin-oriented redirection. They were more likely to attack the kin of an individual after it had attacked their own kin.
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Manson, J. H. (1992). Measuring female mate choice in Cayo Santiago rhesus macaques. Anim. Behav., 44, 405–416.
Abstract: Few studies of female mate choice have been carried out among free-ranging non-human primates. To qualify as female mate choice, behaviour by oestrous females must predict the occurrence or rate of potentially fertile copulations, in comparisons between heterosexual dyads. In this paper, data are presented to show three behaviour patterns that meet this criterion in free-ranging rhesus macaques, Macaca mulatta, at the island colony of Cayo Santiago: (1) selective cooperation with male sexual solicitations (hip-grasps), (2) restoration of proximity following attacks on females by intruding males, and (3) proximity maintenance (in one of two study groups). Oestrous females maintained proximity preferentially to lower ranking males, but this appeared to reflect differences in the tactics necessary to achieve copulations with males of different dominance ranks, rather than preference for lower ranking mates. Male-oestrous female dyads showed consistency over two consecutive mating seasons in which partner was responsible for proximity maintenance. Male dominance rank was positively correlated with copulatory rate with fertile females. However, in one study group, males to whom oestrous females maintained proximity more actively had higher copulatory rates with fertile females, independent of the effects of male dominance rank.
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Boyd, R., & Richerson, P. J. (1992). Punishment allows the evolution of cooperation (or anything else) in sizable groups. Ethol. Sociobiol., 13, 171–195.
Abstract: Existing models suggest that reciprocity is unlikely to evolve in large groups as a result of natural selection. In these models, reciprocators punish noncooperation by with-holding future cooperation, and thus also penalize other cooperators in the group. Here, we analyze a model in which the response is some form of punishment that is directed solely at noncooperators. We refer to such alternative forms of punishment as retribution. We show that cooperation enforced by retribution can lead to the evolution of cooperation in two qualitatively different ways. (1) If benefits of cooperation to an individual are greater than the costs to a single individual of coercing the other n − 1 individuals to cooperate, then strategies which cooperate and punish noncooperators, strategies which cooperate only if punished, and, sometimes, strategies which cooperate but do not punish will coexist in the long run. (2) If the costs of being punished are large enough, moralistic strategies which cooperate, punish noncooperators, and punish those who do not punish noncooperators can be evolutionarily stable. We also show, however, that moralistic strategies can cause any individually costly behavior to be evolutionarily stable, whether or not it creates a group benefit.
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Reeve, H. K. (1992). Queen activation of lazy workers in colonies of the eusocial naked mole-rat. Nature, 358, 147–149.
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Lamprecht, J. (1992). Variable Leadership in Bar-Headed Geese (Anser Indicus) : an Analysis of Pair and Family Departures. Behaviour, 122(1-2), 105–119.
Abstract: This paper reports quantitative leadership differences in semi-captive bar-headed geese (Anser indicus) at different times of the year, and in different types of groups. Leading is defined here as causing the departure or determining the direction of movement of the whole group. No permanent and exclusive leader of a pair or family group was found, rather relative leading frequencies of male, female and young showed a definite shifting pattern. Females led more often than their mates prior to breeding, and on nest pauses during the incubation period, but less often in summer, autumn and early winter. In families there was no difference between the frequencies of male and female leading. Family females led relatively more often than those of pairs without offspring. This difference was related to the presence, not the number, of young. Goslings led the family about as often as the parents during the rearing period in early summer, less often in autumn, winter and next spring. Such differences and changes are to be expected where competence in particular tasks and dependence on partners vary between group members, and where different situations require different abilities. For the geese, the results can be related to the different options of group members and to the different benefits they derive from leaving (or 'staying put') or following (or waiting for the others) in different situations.
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Krause, J., Bumann, D., & Todt, D. (1992). Relationship between the position preference and nutritional state of individuals in schools of juvenile roach (Rutilus rutilus). Behav. Ecol. Sociobiol., 30(3), 177–180.
Abstract: Position preferences of well-fed and food-deprived juvenile roach were investigated in schools of 2 and 4 fish in the laboratory. Food-deprived fish appeared significantly more often in the front position than their well-fed conspecifics. For fish at the same hunger level, individuals at the front of the school had the highest feeding rate. These results represent the first evidence for a relationship between the nutritional state of individual fish and their positions in a school and suggest a functional advantage of the preference.
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Romano, N., Vitale, F., Alesi, D. R., Bonura, F., La Licata, R., Intonazzo, V., et al. (1992). The changing pattern of human immunodeficiency virus type 1 infection in intravenous drug users. Results of a six-year seroprevalence study in Palermo, Italy. Am J Epidemiol, 135(11), 1189–1196.
Abstract: A cross-sectional seroepidemiologic study was carried out between 1985 and 1990 in 1,567 heterosexual intravenous drug users who had been seen at the AIDS Regional Reference Center in Palermo, Italy, to evaluate the rate of human immunodeficiency virus type 1 (HIV-1) seroprevalence in this group and its long-term trend. Sixty serum samples collected from drug users in 1980 and 1983, before the founding of the Center (1985), were tested as well. Some demographic and behavioral risk factors were studied in a subgroup of intravenous drug users enrolled in 1985, 1987, and 1990 for their possible association with HIV-1. These factors were also studied in relation to hepatitis B virus infection, since both viruses share the same modes of spread. These drug users had a higher prevalence of markers for hepatitis B virus than of HIV-1 antibodies, and the prevalence rates in sera collected declined over time for both infections. The presence of both antibodies to HIV-1 and markers for hepatitis B virus was independently associated with the age of the drug user, the duration of drug use, and the year of serum collection. Antibodies to HIV-1 were observed more frequently in females than in males. No relation was found between education or employment status and the presence of HIV-1 antibodies or hepatitis B virus markers. Although new HIV-1 infections still occur, the decline in seroprevalence observed at the end of the 1980s might be related to modifications in social behavior among newer drug users, partial exhaustion of the susceptible population, and increasing risk awareness in more experienced users.
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