Abstract: Dominance has been assumed to be a quality of overwhelming social importance but satisfactory definitions and measures have not been devised. As an indication of predictability of outcome of interaction between animals, it can be explained in terms of ordinary learning processes previous to and during a specific relationship. Agonistic interactions are usually determined and often initiated by the subordinate's behavior, and subordinate behavior is correlated with physiological changes, so that a subordination hierarchy is probably a more useful concept than a dominance hierarchy. Hierarchies develop in stressful conditions, especially in captivity where animals with overresponsive adrenal cortices are at a selective disadvantage. In wild groups hierarchies are tenuous or absent and stress-responsive members are probably advantageous to a group. Group defense and leadership roles are not correlated with rank, but policing is characteristic of high-ranking animals in species where it occurs. There is no evidence that formation of a hierarchy reduces aggression--hierarchies are actually associated with high rates of aggression in primate groups. There is no conclusive evidence that high ranking males have greater overall reproductive success, and an alternative hypothesis that adult males are sexually active for a relatively short stage of their lives fits existing data equally well.

Abstract: In the normal chick, conspicuous visual stimuli induce targetting and pecking together, with vocalization. All three are abolished by lesion of the intercollicular area (ICo) or of connections passing through its medial margin. After such lesions, chicks also cease to treat significant visual stimuli as if they were startling and exciting, and may delay response as a result. However, they are still able to recognise, orient accurately to, and respond appropriately to, a variety of complex visual stimuli (e.g. food grains, copulation object). In addition, they are little affected by strange surroundings. Lesion evidence suggests the mammalian subcollicular area to have similar functions to the ICo and to be homologous with it. A route (present in bird), which is well-known in mammals for its association with threat, defense and escape evoked by strange and frightening objects (amygdala-diencephalic periventricular system-central mesencephalic grey, A-DPS-CMG) is stimuli via the 2 ICo (subcollicular area). Two different mechanisms may be involved caudal to the ICo. One consists of tectal afferents which might modulate the evocation of targetting, pecking and other responses via the tectum. The other is the predorsal system of tectal efferents which may mediate such responses. Classical syndromes of tameness and unresponsiveness produced by various interruptions of the A-DPS-CMG route may depend on interruption of connections to these midbrain mechanisms. Attack is depressed by ICo lesions as one aspect of reduced responsiveness to conspicuous and startling visual stimuli. Avoidance, which is apparently mediated by a separate system, much as in Anura, is facilitated.

Abstract: Seven major types of sampling for observational studies of social behavior have been found in the literature. These methods differ considerably in their suitability for providing unbiased data of various kinds. Below is a summary of the major recommended uses of each technique: In this paper, I have tried to point out the major strengths and weaknesses of each sampling method. Some methods are intrinsically biased with respect to many variables, others to fewer. In choosing a sampling method the main question is whether the procedure results in a biased sample of the variables under study. A method can produce a biased sample directly, as a result of intrinsic bias with respect to a study variable, or secondarily due to some degree of dependence (correlation) between the study variable and a directly-biased variable. In order to choose a sampling technique, the observer needs to consider carefully the characteristics of behavior and social interactions that are relevant to the study population and the research questions at hand. In most studies one will not have adequate empirical knowledge of the dependencies between relevant variables. Under the circumstances, the observer should avoid intrinsic biases to whatever extent possible, in particular those that direcly affect the variables under study. Finally, it will often be possible to use more than one sampling method in a study. Such samples can be taken successively or, under favorable conditions, even concurrently. For example, we have found it possible to take Instantaneous Samples of the identities and distances of nearest neighbors of a focal individual at five or ten minute intervals during Focal-Animal (behavior) Samples on that individual. Often during Focal-Animal Sampling one can also record All Occurrences of Some Behaviors, for the whole social group, for categories of conspicuous behavior, such as predation, intergroup contact, drinking, and so on. The extent to which concurrent multiple sampling is feasible will depend very much on the behavior categories and rate of occurrence, the observational conditions, etc. Where feasible, such multiple sampling can greatly aid in the efficient use of research time.

Abstract: The green monkey,Cercopithecus sabaeus, has not been studied in its natural habitat in West Africa. This paper reports observations made during a 3-month study in Senegal. Green monkeys live in multimale groups averaging some 12 individuals. Information is given on home range size, use of habitat, daily activity patterns, diet and birth seasonality. Social organization is discussed and data are given on the relationships between age-sex classes, aggression and leadership. Inter-group relations are discussed and it is suggested that groups defend their ranges as territories. The ecology and social organization of green monkeys is compared with that of populations ofC. aethiops studied in East Africa and they are found to be similar.