Variation in the choice of foods
on a daily, seasonal, and yearly basis is one of the greatest differences
between primate species.
Primate diets have generally been divided into three main food categories -- fruit, leaves and fauna (including insects, spiders, and bird's eggs for the most part.) The different diets also are referred to as FRUGIVORES, FOLIVORES, and INSECTIVORES (fruits, leaves and insects respectively.) These gross dietary categories are correlated with aspects of primate activity patterns such as home range and group size. There are different problems that have to be overcome in order to obtain a balanced diet on a day-to-day basis. New leaves and mature leaves, for example, may have different nutritional bases or availabilities. Some fruits appear in large clumps while others are spread thinly over a larger area. Foods such as gums, seeds and nectar often require unique adaptations.
Aside from diet, primates have tended to either adapt through specialized dentition and digestive systems or rely on a variety of different foods. Those that chose this second route have tended to have larger brain sizes relative to their overall body size. This may be due to the need to know where different types of food can be found at different times throughout the year.
Have you ever looked at a picture
of a gorilla or a monkey that has what appears to be a "beer belly" look?
Those primates that specialize on eating large amounts of vegetation have
difficulty digesting their meals. Different solutions have been found including
double stomachs or multichewes, but the problem usually requires an individual
to sit back and let the digestive system work - and on the side expel gas....
