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.

Abstract: Much of the social behavior and organization of ungulates can be related to ecological parameters such as fiber content of forage, plant productivity, plant biomass, plant species diversity, productivity gradients, temporal and spatial fluctuations in productivity, habitat stability, food dispersion, three-dimensional structure of habitat, colonization, and predator density and diversity. These ecological variables can be linked via individual natural selection with the species' anti-predator strategies, emphasis on different channels of communication, relative frequency of damaging and non-damaging overt aggression, gregariousness and group structure, juvenile dispersal, home-range traditions, monogamy and polygamy, sexual dimorphism, territoriality, hierarchical rank structure, and plasticity of social structures. The ecological variables have primary manifestations which are behavior or which affect behavior, as well as secondary manifestations affecting behavior. There are logical links between the hypothesis linking ecology and behavior discussed here with some principles from bioenergetics, zoogeography, and paleontology. Although links do exist between ecology and behavior, they nevertheless represent distinct realms of natural selection in which social behavior appears as the more conservative element. The theoretical basis for this is discussed.

Abstract: Attempts to relate interspecific differences in social organisation among primates to gross differences in habitat or diet type have been largely unsuccessful. This is probably partly because distantly related species have adapted to similar ecological situations in different ways and partly because much finer ecological differences are important.