Omnivore (Omnivorous Animal)

Omnivores are animals that regularly eat both plant-derived and animal-derived foods as part of their normal diet. They may also consume fungi, detritus, or microbes, with the proportions of each dietary component varying by their species, habitat, season, or life stage.¹

Their plant-derived foods typically include fruits, seeds, nuts, leaves, roots, nectar, and grains, while their animal-derived foods can include insects, eggs, larvae, fish, small vertebrates, and carrion.

Omnivore vs Herbivore vs Carnivore

An animal is considered an omnivore only if it consumes both plant-derived and animal-derived foods as a regular, meaningful part of its diet. This is what separates omnivores from herbivores and carnivores. Herbivores have a primarily plant-heavy diet, whereas carnivores have a primarily animal-heavy diet. Omnivores fall between these two categories because their diets normally include both.

However, the balance is not perfectly equal. For example, some omnivores tend to be plant-heavy (plant-feeding omnivores), such as brown bears feeding on berries, nuts, and roots. In contrast, others tend to be more animal-heavy (prey-feeding omnivores), such as foxes that eat insects, eggs, or carrion while also consuming fruit when available.² Some are generalist omnivores, meaning they consume a broad mix of plant and animal matter, instead of leaning toward either.

In many omnivores, these dietary patterns are also opportunistic or seasonal, meaning they can switch their diet depending on which resources are easiest to find at a particular time of year.

Examples

Omnivores occur across many animal groups, but they do not all use mixed diets in the same way. The table below shows common examples of omnivores and the type of omnivory each one best represents.

Animal Group	Example	Type
Mammals	Pigs	Generalist omnivore (opportunistic, seasonal)
	Raccoons	Generalist omnivore (opportunistic, seasonal)
	Rats	Generalist omnivore (opportunistic)
	Mice	Generalist omnivore (opportunistic)
	Dogs	Generalist omnivore (opportunistic)
	Foxes	Prey-feeding omnivore (opportunistic, seasonal)
	Skunks	Prey-feeding omnivore (opportunistic, seasonal)
	Badgers	Prey-feeding omnivore (opportunistic, seasonal)
	Brown Bears	Generalist omnivore (opportunistic, seasonal)
	Black Bears	Plant-feeding omnivore (opportunistic, seasonal)
	Humans	Generalist omnivore (culturally variable)
Birds	Crows	Generalist omnivore (opportunistic)
	Chicken	Generalist omnivore (opportunistic)
	Ducks	Generalist omnivore (seasonal)
	Gulls	Prey-feeding omnivore(opportunistic, seasonal)
Reptiles	Many Turtles	Generalist omnivore (Life-stage dependent)
Fish	Catfish	Generalist omnivore (opportunistic)
Insects	Cockroaches	Generalist omnivore (opportunistic)
	Ants	Generalist omnivore (opportunistic)

Although omnivores can feed on a wide variety of sources, they are usually not specialized for a particular food type. While a specialist herbivore can handle tough plant material, or a specialist carnivore may be better at catching and killing animal prey, omnivores lie in between the two in terms of efficiency.

Since these animals feed at different trophic levels,³ they affect several components of the ecosystem at once. While plant-feeding omnivores considerably affect plant communities, those that lean toward animals can affect prey populations.⁴ Additionally, those that scavenge on carrion contribute to the recycling of nutrients in the environment.