(Referenced according to Journal of Animal Science)
Assignment 2.2: Review outline
How do resource abundance and distribution affect the social structure of primate societies? Introduction
Originating in the 1970s, research on the relationship between ecology and social structures in nonhuman primates was partially centered on the effect of food abundance and distribution, on group size and of diet on group size and population density (Isbell, 1991). (Wrangham 1980) paper on the evolution of female-bonded groups in general and ape social structure in specific moved the focus to female social relationship. Primate social structures are the results of natural selection in a specific habitat. Most primates, including humans, spend their lives in large social group or communities (van Schaik, 1983). Some species are semi-terrestrial e.g. baboons. In their case being in large community provide them with protection against predatory dogs and hyenas (Altmann, 1974). Social structure also helps protect scarce food resources. This is mostly true for nonhuman primate which consumes fruit. Leaf-eaters, such as langurs, tend to form smaller social groups since there is little competition for food. Nonhuman primate communities closed to contact with members of other communities. Most often, they are tied to their local habitat and rarely migrate outside other of their home range. Primates are among the most social of animals, so primate social behavior is one of the major topics in this review. Primatologists aimed to build the network of behavior interaction (Hinde 1976), with reference to variation in resource distribution and feeding competition. The variety of primate social systems has been described and analyzed in review by van Schaik (1983). Aspect of this diversity included grouping and matting patterns, as well as variability in patterns and quality of social structures. Furthermore, diversity in social system is not only evident in inter species but also exists in intra species and even within populations (Cheney, 1992). However for reason of simplicity I will look at how resource abundance and distribution will affect the social structures of the primate societies (Kappeler and van Schaik, 2002).
Factors that influence primate social structures:
Body size- larger animals require fewer calories per unit of weight then smaller animals. Therefore, larger animals are able to retain heat and their overall energy requirements are less than for smaller animals. Being a smaller size primate is also advantageous because small primates are highly mobile through dense forest; this is so because they can move quickly from tree to tree. Large primates move more deliberately through trees, since not every branch can withstand their weight. Also large primate can defend themselves against big cats, but many small ones cannot (Altmann, 1974). Distribution of resources-The distribution of resources affects the type of competition in primate which can either be clumped or dispersed (Isbell, 1991). Clumped also known as contest competition, resources are scarce and valuable. Moreover, resources are worth fighting over and primate contest access to particular resources. Dispersed also known as scramble competition it has low valuable patches. Food item is not worth fighting over, primate species they scramble to get enough food and there is no direct competition. The distribution of food affects the group size (social structure). Foraging for food is one of the major activities that primates conduct on a daily basis. Whether a group of primate is large or small, every individual must eat. Life is convenient for a group of primate that has a huge tree with ripe fruit. This means that they can eat and stay there as long as they are not driven off by competitors or predators. If such large patches are common enough, than the primate can stay in a large group and move from...