many birds eat both fruits and insects which makes them omnivores. mammals may eat both fruits and protein, or eat mostly fruit or nectar, such as many bats. one primate group is essentially herbivore/frugivore, the owl monkeys. they live in a non-seasonal area of the amazon that supports a constant supply of fruiting trees. elsewhere, an exclusively frugivore diet is impossible and is supplemented by insects or rougher plant matter. some people say that humans are frugivores; this is unlikely given the evolution of man in the dry tropical region of the rift valley. however, the climate in the rift valley at the time of our evolution was likely a tropical rainforest. that said, almost all primates and even carnivores will travel great distances to feast when a fruit tree has dropped its ripened fruit. many species will remember the exact fruiting date and location of a fruiting tree which highlights fruits great nutritional benefit. some people promote a frugivore diet for humans.