Abstract: Herding behavior in ungulates is executed mainly by males. There are several forms of herding: guarding a single estrous female; rounding up a bunch of females during the rutting season; territorial herding by which a male keeps females inside his territory; herding of a moving, permanent, harem group; social herding in which group members of both sexes are herded by one dominant male. When put into this sequence, a phenotypical trend is illustrated, leading from an intimate connection of herding with mating behavior toward an increasing independence from sexual behavior and culminating in a complete socialization of herding. Aspects and problems of herding behavior are the recognition of, and the animal's respect for, partners in gregarious species; the animal “taking offense” at activities of others which deviate from its own activity; the active coordination and synchronization of group activities; the use of, and the effects of, threat, dominance and courtship displays in herding; the possibility of substitution among expressive displays in relation to partners of different sex; the communicative function of the animal's orientation relative to the partner; social hierarchy and leadership in a group; the possibility of interspecific herding, particularly in man-animal relationships, which is closely linked to the process of domestication.

Abstract: Summary The introduction of game-theoretical thinking into evolutionary biology has laid the groundwork for a heuristic view of animal behaviour in which individuals employ “strategies” – rules that instruct them how to behave in a given circumstance to maximize relative fitness. Axelrod and Hamilton (1981) found that a strategy called Tit-For-Tat (TFT) is one robust cooperative solution to the iterated Prisoner's Dilemma game. There exists, however, little empirical evidence that animals employ TFT. Predator inspection in fish provides one ecological context in which to examine the use of the TFT strategy.

Abstract: Feeding habits of free-ranging wildebeest and zebra were monitored in a semi-arid nature reserve, bordering the southwestern part of Kruger National Park, South Africa. The purpose of study was to distinguish and define the feeding niches of two roughage grazers that occur in similar habitat types. The monthly compositions of diets were evaluated by direct observations of feeding bouts over a period of two years when rainfall patterns were average and animal populations were stable. Other analyses evaluated the standing biomass of grass species in the reserve during the wet summer and dry winter seasons.
A considerable overlap of grass species composition was found in the diets of wildebeest and zebra. Ordination of bi-monthly records of the diet composition showed greater variations in scores of grasses in zebra diet in comparison to wildebeest. Seasonal patterns were more apparent in the wildebeest diet. Preference ranking of grass species indicated that zebra diet remained constant in winter and summer. Wildebeest diet however, alternated with seasons, showing high preferences during the winter months for grass species which were rejected during summer.
The combined assessment of results from three separate statistical methods analysing temporal patterns and preferences in diet composition revealed contradictory trends. The solution, however, relied on the initial assumptions posed. Hence, wildebeest and zebra are essentially generalist feeders which show a limited amount of preference in their choice of diet.

Abstract: Forced copulation and induced abortion were investigated in a herd of feral horses inhabiting a coastal barrier island. Eight mares were diagnosed pregnant in August and October 1989 by means of urinary and fecal steroid metabolites, prior to documented changes in herd stallions. These mares were observed for harassment and forced copulation by the new stallions and for the presence of foals during the spring and summer of 1990. No incidents of harassment or attempts at forced copulation were witnessed and seven of the eight mares produced foals in 1990. These data indicate that forced copulation and induced abortion are not common events among all feral horse herds and suggest reinvestigation of this hypothesized phenomenon.

Abstract: Alliances among kin play a major role in a female's acquisition of her mother's dominance rank in many species of cercopithecines. It is noteworthy, however, that kin rarely form coalitions to challenge females from higher-ranking matrilines, and that matrilineal hierarchies are remarkably stable. One possible reason for the rarity of destabilizing coalitions is that members of high-ranking matrilines form alliances against lower ranking ones. In this paper the patterning of aggressive support among non-kin, and its effect on the stability of rank relations are analysed in a captive group of Japanese macaques, Macaca fuscata, composed of three unrelated matrilines. Analysis of the distribution of non-kin interventions in conflicts between matrilines over a 52-month period revealed a clear pattern of preferential support between the two dominant matrilines against the third-ranking one. This pattern was confirmed experimentally. Any member of the two dominant matrilines was unable, individually, to maintain its rank above the third-ranking matriline, but was able to do so in the presence of the other dominant matriline. Non-kin alliances appear to prevent subordinate females from challenging higher ranking females through revolutionary coalitions (formed among subordinates) or through bridging coalitions (formed among individuals ranking above and below the target). Non-kin support is interpreted in terms of cooperation versus reciprocal altruism.