What is a frugivore?
Frugivores are animals whose preferred food is fruits and thus have adaptations for foraging fruits. Highly frugivorous animals eat mainly fruits, but most frugivores also eat other types of foods. Frugivores can be a sub-class of omnivores or herbivores.
Frugivores are mainly found in tropical areas, where wild fruits are bigger and more nutritious than those that the temperate flora can produce. In the tropics, fruits are available throughout the entire year and can sustain frugivorous animals.
Frugivores are often the seed-disperser of the fruit-bearing plant. One plant can have more than one fruit-disperser, but generally, fruits and their frugivore evolve together. This is also called the “dispersal syndrome,” where fruit traits are shaped by the frugivores’ preferences.
Depending on the animal type (birds, mammals, insects, etc., see below), the frugivores’ adaptations to fruit foraging and fruit preference are very different! This is also the reason why some types of fruits can be toxic to one frugivorous species but not to another species – depending if they have co-evolved or not.
Types of frugivores
There are frugivorous animals among many animal classes, like mammals (including primates), birds, reptiles, and insects. Weirdly, frugivore research has long mainly focused on birds – not on our closest relatives, the primates. Research on frugivory in primates includes humans and should therefore be of major interest to understanding our natural diet.
Examples of different types of frugivores: Orangutans, toucans, grey parrots, maned wolves, iguanas, fruit bats (flying fox), some turtles and lizards, and fruit flies. All of the larger frugivores are tropical species.
Are humans frugivores?
Humans are taxonomically placed within the family of great apes, of which all are highly frugivorous (including gorillas). Humans are not only genetically closely related to other apes, we are also highly attracted to fruits in nature, and our biology is typical for a tropical frugivorous (primate) species. When looking at human dietary anatomy and physiology, it is hard to deny the frugivorous traits of humans – and that we should consider a re-classification as frugivorous omnivores, like our closest relatives, the chimpanzees. A frugivorous omnivore is able to eat a broad range of foods, but their preferred and optimal foods are fruits in the wild.
We, humans, do not live in our original natural habitat like chimpanzees do. We have learned to cook and eat “non-foods,” which are not really our natural foods from an evolutionary perspective. We are cultural omnivores, but biologically we are still frugivores! This is why we are so confused about our diet today.
Are humans adapted to a fruit diet?
Humans share most diet-related biological characteristics with frugivorous primates: Digestive tract, microbiome, and color-vision are just a few examples. One interesting trait is that we have lost the internal production of vitamin C (genetic mutation). This means we need to obtain a large amount of vitamin C from our diet, while most mammals produce vitamin C themselves! Many frugivore species have lost vitamin C production independently, like frugivorous bats, guinea pigs, and all primates (read more here).
Many more features are perfectly shaped for fruit-eating, which equips humans as specialized frugivores in nature! Learn more:
Aren’t chimpanzees omnivores?
Yes, chimpanzees are classified as omnivores. More specifically, chimpanzees are frugivorous omnivores. Chimpanzees are animals that can eat meat and plant matter, therefore they are omnivores. However, their preferred food in tropical forests is fruits. Thus the sub-classification is clearly frugivore. This is reflected in scientific literature, which refers to chimpanzees as frugivores, or highly frugivorous primates. So what does such a diet look like in nature?
In the wild, chimpanzees (Pan troglodytes) eat mainly fruits, but also other plant foods and also some animal foods. Bonobos (Pan paniscus) – the chimpanzee species which is closest related to humans – are classified as omnivorous frugivores. This is because they eat even less animal foods than Pan troglodytes.
According to the Jane Goodall Institute, Chimpanzees eat fruits (preferred), figs, nuts, and seeds. Flowers, barks, and leaves are second choice foods when fruits are scarce. Insects make up to 4% of the diet. Animal products (which include eggs, insects, and meat) can make up to 6% of the diet. Read our in-depth article on the chimpanzee diet here:
What is a frugivorous diet?
A frugivorous diet describes the foods foraged by frugivorous animals in nature. For frugivorous primates, this means ripe tropical fruits, greens, nuts, and tubers, but also eggs, insects, and sometimes meat. Frugivorous primates can only exist in the tropics, where fruits are larger, more nutritious, and abundant throughout the year.
Diets of frugivorous animals vary among species and even populations or within populations depending on food availability. For example, the generally frugivorous primates – macaques, chimpanzees and capuchins – in Thailand are known to eat shellfish. They use tools, a specialized behavior, in which the capuchin monkey seems to apply their shell-cracking skills on shellfish, which they already know from the handling of their favorite hard-husked palm-tree fruit called Cumare. Frugivorous chimpanzees even hunt smaller monkeys. However, there are strong indications that hunting is not a dietary or nutritional “thing” but rather a socially motivated behavior among males.
To know more about the human version of a frugivorous diet, visit this article:
What is a fruitarian diet?
A fruitarian diet is most often described and understood as a fruit-only diet. However, some fruitarians include greens, nuts, sprouts, raw veggies, or sometimes even cooked sweet potatoes, depending on food availability in their area. In its optimal form, a fruitarian diet relies on tropical fruits and stands on the observation that humans are most likely frugivores. However, being a fruitarian is a choice – like being vegan. On the contrary, being frugivorous is not a choice – it is the dietary ecology of an animal naturally given by its biological features.
Learn more here:
What about hunter-gatherers?
Before agriculture, humans were hunter-gatherers with locally varying diets, including meat, plant foods, and cooking. However, humans originated in the tropics, where they likely had more of a frugivorous diet – and we are still biologically adapted to fruit-eating. Humans were able to migrate out of the tropics mainly through cultural adaptations, not biological adaptations. Thus our hunter-gatherer past does not exclude our frugivore biology. Read more about this here:
Have humans co-evolved with fruits?
Primates – and originally humans – are seed dispersers and have coevolved with their fruits. This is also called the “dispersal syndrome.” Because primates are tropical animals, we have evolved with tropical fruits, while most ancient temperate fruits were dispersed by birds. Because of the symbiotic relationship between fruits and frugivores, both species are shaped by each other: the fruits evolve according to the frugivores’ preferential taste, color, etc., while the frugivores’ dietary traits specialize in foraging and digesting their foods.
Go to How to do the Frugivore Diet
References
- Frugivore (2022) Wikipedia. Wikimedia Foundation. Available at: https://en.wikipedia.org/wiki/Frugivore#Frugivore_adaptations_for_fruit_consumption (Accessed: April 3, 2023).
- K. Valenta, O. Nevo, The dispersal syndrome hypothesis: How animals shaped fruit traits, and how they did not. Functional Ecology. 34, 1158–1169 (2020), doi:10.1111/1365-2435.13564. (link)
- Dani Sarusi, 10 things chimpanzees eat. Jane Goodall (2022) (available at https://janegoodall.ca/our-stories/10-things-chimpanzees-eat/). (link)
- Woodward, A. (2017) Tool-wielding monkeys push local shellfish to the edge of extinction, New Scientist. New Scientist. Available at: https://www.newscientist.com/article/mg23531441-900-toolwielding-monkeys-push-local-shellfish-to-edge-of-extinction/ (Accessed: April 3, 2023).
- Izawa, K. (1979) “Foods and feeding behavior of wild black-capped capuchin (Cebus apella),” Primates, 20(1), pp. 57–76. Available at: https://doi.org/10.1007/bf02373828. (link)
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