Birds are diverse creatures that eat a variety of things. The majority of birds are actually herbivores, which means that they primarily eat plants supplemented with a few insects, but most birds will eat what is most readily available to them.
Some birds, however, like hawks, eagles and vultures are carnivores and eat mostly meat as their digestive system does not tolerate plants well.
Most birds are omnivores and they typically eat various things, including fruits, vegetables, seeds, nuts, and insects.
In fact, only 2% of bird species eat a diet consisting of more than 95% plants! These include the hoatzin of the amazon rainforest and certain waterfowl.
Different bird species have different diets depending on what is available to them in their environment. For example, finches primarily eat seeds while parrots enjoy eating fruit, and birds of prey are pure carnivores.
The diet of a bird also depends on its size. Smaller birds tend to eat more seeds and insects since they require more protein to maintain their body weight. But larger birds may have an easier time overwhelming other animals, so they can be primarily carnivores.
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So most birds eat plants?
Almost all birds, with the exception of the predatory types, are herbivores to some extent, yes!
So most birds’ diets consist largely of vegetable matter, although a few species, the flamingos, or crows, for example, can be almost entirely carnivorous if needed.
Most birds consume their vegetable food in the form of seeds, fruit, and other plant parts, but the great majority of them feed chiefly on the seeds, leaves, buds, and flowers of plants.
Birds that feed on insects may do so extensively, as, for example, those that eat locusts, grasshoppers, or caterpillars as their main diet, or they may prefer insects but will take an occasional plant, fruit, or seed when the opportunity arises. These omnivorous but mainly carnivorous birds include the Jays and the crows that are largely omnivorous.
Many birds, such as sparrows, feed mainly on grains, berries, and nuts but their exact diet depends on their habitat and the season of the year. As such, the animal content of their diet varies throughout the year.

Many birds eat more fruit in autumn and more insects when available in the spring and summer. And some birds that do not naturally eat a lot of animals in their diet, have become much more opportunistic in their dietary preferences after human cities started to emerge.
For example, birds like pigeons and seagulls only became truly omnivores when they became adapted to human settlements, where they will eat whatever, animal or plant, that is available to them. This ability to consume a broad diet is now part of their immense success!
A broad diet makes birds important to the ecosystem
Birds are important for the ecosystem for a variety of reasons. As omnivores, they help to control populations of other animals by eating them, and as herbivores they help to spread seeds and pollinate flowers.
The presence of certain bird species is therefore also an indication of environmental health!
Birds play an important role in controlling populations of for example insects by eating them. This helps to keep the population of the insects, but also the other animals eating the insects in check and prevents them from becoming too abundant.

This is important because if one species becomes too abundant, it can upset the balance of the ecosystem and lead to problems such as disease outbreaks or habitat destruction.
Birds also help to spread seeds and pollinate flowers. By doing this, they help to ensure that plants can continue to grow and thrive. However, some birds also eat the actual flowers, which, ironically can also help the pollination of the flowers that survive!
This is important because plants are a vital part of the ecosystem and provide food and shelter for many other animals.
Finally, birds can be indicators of environmental health. Because they are so sensitive to changes in their environment, they can be used to monitor pollution levels or other factors that may be adversely affecting the ecosystem.
Are All Birds Either Carnivores, Herbivores, or Omnivores?
The terms carnivore and omnivore as applied to birds are often misunderstood. Many bird watchers and ornithologists use carnivore and omnivore in a very broad sense for the entire class Aves, and this is where the confusion arises.
Carnivores and herbivores in this case refer to animals that eat mostly meat or mostly eat plants, respectively. However, many species of bird are difficult to categorize, as many are facultative carnivores and omnivores and very few eat plants exclusively.
Very few birds are pure herbivores because they will almost always eat an insect or two or some other animals. For example, most geese and swans do not want to eat other animals, but they do so unintentionally when eating from the water where thousands of microscopic animals (zooplankton) is found!
In fact, only 2% of bird species have a diet mostly consisting of plants, and even fewer are purely vegetarian!
One bird that is a true herbivore is the hoatzin bird of the Amazon rainforest. The hoatzin is a South American bird that is only found in the Amazonian rainforest. Its diet consists of leaves, flowers, and fruit but no animals at all!
The hoatzin has a long neck and legs, and it can grow to be about two feet tall and 2lbs heavy.
Its wings are short and rounded, and it does rarely fly but it lives high up in the trees, usually near rivers, so that predators cannot get to them!
They have a strong smell that is produced by bacteria in their gut. These bacteria are important for their digestion and are the main reason that they are able to survive on leaves alone.
The hoatzin is a bit like the proboscis monkey or a cow in that it can survive on plants alone via fermentation of the plant material into the proteins and fats that they need to grow!
Examples of mostly herbivorous birds are:
- Geese (especially the Snow Goose and Nene Goose)
- Grebes
- Swans
- Emus
- Takahe
- Kakapo
- Lorikeets
- Most parrots
- sage-grouse
These birds, especially the waterfowl, will accidentally eat small animals like zooplankton, when they sieve through the water for plants and algae, so they are not strictly herbivorous.
You might wonder: why are hummingbirds not on this list as they eat nectar? But in fact, no bird can live exclusively on nectar as it lacks some vital proteins, fats, and vitamins for the bird to grow!
So even though they may seem to eat nectar all the time, they do indeed snap an insect out of the air once in a while!
Omnivorous birds:
- Pigeons
- Crows and ravens
- Jays (such as the blue jay)
- Blackbirds
- Starlings
- Flamingos
- Sparrows
The list is in fact much longer as most birds are in reality omnivorous, but these are some of the most “balanced” omnivores eating almost equal ratios of plants and animals.
Other birds may occasionally ingest plants, but aim to eat a purely carnivorous diet.
These carnivorous birds are:
- Eagles
- Ospreys
- Falcons
- Owls
- Hawks
- Vultures
- Herons
- Storks

Is a Bird a Producer, Consumer, or Decomposer?
All animals can technically be considered consumers, as they need to consume their energy from plants or other animals.
The herbivorous birds described above are considered primary consumers, whereas omnivorous birds can be both primary and secondary consumers.
Those on the last list are purely carnivorous and are therefore considered tertiary or quaternary consumers (apex predators).
Where are herbivorous birds in the Food Chain?
Birds are in the middle of the food chain and most are secondary or primary consumers. Herbivorous birds are exclusively primary consumers, and many omnivorous birds belong mostly to this category as well.
But whereas they mostly eat plants, seeds and berries they do also eat the insects that live in plants or worms they find in the ground. Therefore most birds also act as secondary consumers.
Plant eating birds are heterotrophs because they obtain energy from the food they eat rather than using sunlight for energy as some bacteria, algae, and plants do. This means that they channel energy up through the food chain into, the much less energy-efficient, carnivores.
Birds may also use other animals such as insects or fish for energy, which classifies them as facultative carnivores. However, most species of birds are exclusively herbivores, as they eat only plants for food.
What Eats Herbivorous Birds? (Who are their enemies?)
Birds are eaten by mammals, reptiles, amphibians, fish, some insects, and other birds.
The birds that are herbivores are usually also less defensive than those that are predators and birds of prey, such as hawks, eagles, and owls will also hunt and kill smaller birds.

Mammals such as foxes, cats raccoons, and opossums will sometimes eat bird eggs, but birds like magpies, crows, and jays will also do so.
Birds have evolved different strategies to avoid predators. Some species will form flocks and take turns sleeping and standing watch.
Others will roost in trees with dense foliage that makes it difficult for predators to approach. Still, others will nest in cavities or on ledges where they can see approaching predators.
Birds also have a variety of vocalizations they use to warn other birds of danger and in addition to being alert to the presence of predators; many birds will also try to camouflage themselves or their nests by building them to blend in with the surroundings.
Conclusion
Birds can be both herbivores, omnivores and carnivores. The majority of birds are actually herbivores, which means that they primarily eat plants. Some birds, however, are carnivores and eat mostly meat.
Some birds may even act as cannibals that kill their own offspring!
Different bird species have different diets depending on what is available to them in their environment, but most birds are primarily herbivorous and will eat various things, including fruits, vegetables, seeds, nuts, but also insects.
For example, finches primarily eat seeds while parrots enjoy eating fruit and do not seek out animal food very often.
Almost all birds, with the exception of the predatory types, are herbivores to some extent. Their diet consists largely of vegetable matter, although a few species, the flamingos, for example, are partially carnivorous but eat mostly algae.
Birds are important for the ecosystem for a variety of reasons. As omnivores, they help to control populations of other animals by eating them, and as herbivores, they help to spread seeds and pollinate flowers. The presence of certain bird species is therefore also an indication of environmental health!