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Heyes, C. M. (1993). Imitation, culture and cognition. Anim. Behav., 46(5), 999–1010.
Abstract: Abstract. This paper examines the significance of imitation in non-human animals with respect to the phylogenetic origins of culture and cognitive complexity. It is argued that both imitation (learning about behaviour through nonspecific observation) and social learning (learning about the environment through conspecific observation) can mediate social transmission of information, and that neither is likely to play an important role in supporting behavioural traditions or culture. Current evidence suggests that imitation is unlikely to do this because it does not insulate information from modification through individual learning in the retention period between acquisition and re-transmission. Although insignificant in relation to culture, imitation apparently involves complex and little-understood cognitive operations. It is unique in requiring animals spontaneously to equate extrinsic visual input with proprioceptive and/or kinaesthetic feedback from their own actions, but not in requiring or implicating self-consciousness, representation, metarepresentation or a capacity for goal-directed action.
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Barton, R. A., & Whiten, A. (1993). Feeding competition among female olive baboons, Papio anubis. Anim. Behav., 46(4), 777–789.
Abstract: Abstract. Competition for food is thought to play a key role in the social organization of group-living female primates, leading to the prediction that individual foraging success will be partly regulated by dominance relationships. Among adult females in a group of free-ranging olive baboons, dominance rank was significantly correlated with nutrient acquisition rates (feeding rates and daily intakes), but not with dietary diversity or quality, nor with activity budgets. The mean daily food intake of the three highest-ranking females was 30% greater than that of the three lowest-ranking females, providing an explanation for relationships between female rank and fertility found in a number of other studies of group-living primates. The intensity of feeding competition, as measured by supplant rates and spatial clustering of individuals, increased during the dry season, a period of low food availability, seemingly because foods eaten then were more clumped in distribution than those eaten in the wet season. Implications for models of female social structure and maximum group size are discussed.
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Barton, R. A. (1993). Sociospatial mechanisms of feeding competition in female olive baboons, Papio anubis. Anim. Behav., 46(4), 791–802.
Abstract: Abstract. Social and spatial mechanisms of feeding competition among adult female olive baboons were studied in two free-ranging groups, one foraging for natural foods, and one that was being provisioned. Similar behavioural processes were found to underlie rank-related differences in food intake in the two situations. Dominance rank of females in the naturally foraging group was positively correlated with the rate at which other animals were supplanted from feeding sites, the ratio of supplants of others to supplants received, and the number of near neighbours while feeding on clumped foods. It is unlikely that the latter result was due to rank-related differences in matriline size, because no significant correlations between rank and neighbour density were found for non-feeding activities. Step-wise regression analysis indicated that both number of neighbours and the supplant ratio explained significant proportions of inter-individual variance in daily food intake, though only the supplant ratio contributed significantly to feeding rate. High-ranking females also had priority of access to feeding sites within trees, and competition was most intense for foods that were spatially clumped. Similarly, in the provisioned group, rank was correlated with the rate at which supplants were received, and with spatial indices estimating centrality and the area of unoccupied space around an individual. Over 99% of the inter-individual variance in feeding rate was explained in a step-wise regression with supplant rates and spatial indices as independent variables. It is concluded that both active supplanting and individuals' spatial positions within the group mediate rank-related differences in food intake.
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Goldschmidt, T., Bakker, T. C. M., & Feuth-de Bruijn, E. (1993). Selective copying in mate choice of female sticklebacks. Anim. Behav., 45(3), 541–547.
Abstract: There is evidence that female three-spined sticklebacks, Gasterosteus aculeatus L., prefer to mate with males whose nests contain eggs rather than with males with empty nests. While there is consensus on this point, a dispute exists about whether this preference should be attributed to a direct effect of the eggs on the female's entering the nest or, alternatively, to a positive impact of the eggs on the courtship behaviour and breeding coloration of the male. In the field experiment reported here females strongly preferred nests with eggs over empty nests. Additionally, females were less likely to enter risky nests with eggs: nests that contained fewer eggs than one average clutch or more eggs than the average nest content of parental males in this population. However, in the field possible differences in male attractiveness were not controlled for. In supplementary laboratory experiments the effect on female choice of possible changes in male attractiveness (intensified courtship and coloration) as a result of the presence of eggs in the nest was tested. Other differences in male attractiveness as a result of differences in male quality (body size, breeding coloration before the test, territory quality and size) were controlled for. When females had no access to the nests, they showed no preference for males with eggs in their nests in simultaneous choice tests. These results, together with the earlier published data, make it likely that the preference of females for nests with eggs is partly a direct consequence of the eggs themselves. So female sticklebacks are influenced by the mate choice behaviour of other females, but remain selective as to the actual nest content.
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Genov, P. W., & Kostava, V. (1993). Untersuchungen zur zahlenmäßigen Stärke des Wolfes und seiner Einwirkung auf die Haustierbestände in Bulgarien. Zeitschrift für Jagdwissenschaft, 39(4), 217–223.
Abstract: Die Untersuchung wurde in der Zeitspanne von 1984 bis 1988 durchgeführt. Es wurden die Protokolle des Staatlichen Versicherungsinstituts benutzt, die Angaben für Raubüberfälle von Wölfen auf Haustiere beinhalten (Tabelle 1). Außerdem wurden Angaben über die während dieser Zeitspanne erlegten Wölfe zusammengefaßt. Die Abschußzahlen lauten: 1984 – 163, 1985 – 147, 1986 – 179, 1987 – 211 und 1988 – 220 Tiere. Die Anzahl der in den einzelnen Gebirgen lebenden Wölfe wurde nach einer Umfrage festgestellt. Für die in Betracht kommenden Gebirge werden folgende Bestandszahlen angenommen: Rhodopen -- 60-80 Individuen, 189 bis 264 km2 pro Tier, Rila- und Piringebirge -- 60-80 Tiere, 109 bis 145 km2 pro Tier, Ossogowo-Belassiza Gebirgssystem -- 40-50 Individuen, 57-70 km2 pro Tier, West- und Mittelbalkan -- 35-38 Wölfe, 200 km2 pro Tier. Dazu kommen noch 10-15 Wölfe im Flußbecken von Beli Lom und etwa 20 Exemplare in Strandscha- und Sakargebirge. Insgesamt lebten in Bulgarien im Jahre 1988 etwa 260-330 Wölfe (Abb. 1).
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