Herbivorous Birds: Examples and Characteristics

Written and verified by the biologist Cesar Paul Gonzalez Gonzalez

Written by Cesar Paul Gonzalez Gonzalez

Last update: 24 June, 2023

Birds come in different species, shapes, sizes, colors, and appearances. In fact, there are about 29 different taxonomic orders of this type of animal, which group together the more than 10,500 species that exist in the world. In this article, we’re going to take a look at herbivorous birds.

Birds have adapted to their ecosystems and the resources they find there. Thanks to this, birds have developed different food preferences, which can be classified into herbivores, carnivores, scavengers, omnivores, and insectivores. We’ll be focusing on the first one on the list in this article!

What are the characteristics of herbivorous birds?

Within the animal kingdom, the herbivorous diet is one of the most complicated and difficult to maintain, as it isn’t always easy to obtain nutrients from plant matter. Because of this, birds that have this type of preference have had to develop different adaptations that allow them to facilitate the digestion of their food. Among the most common features of these animals are:

1. A modified beak

Their beaks are a horny (hardened) structure that allows them to manipulate, chop, and grind their food. In the case of herbivorous birds, their beaks tend to be short and wide, as this makes it easier to crush, cut, and open different types of seeds, fruits, and some herbs.

2. A digestive system modified to fruits and plants

Although it’s true that the beak is a fundamental structure to begin the digestion of plant species, the reality is that it isn’t enough to obtain their nutrients. Because of this, herbivorous birds have had to modify their digestive system to better process their food.

The main problem with a herbivorous diet is that the cell wall of plant cells is harder and more resistant. Consequently, the crushing of the beak is not enough for them to release their contents (the nutrients). This is why birds have developed structures such as the gizzard, which is a special stomach muscle that helps to crush food.

3. A long intestine

Although birds are characterized by a shorter intestine than any other animal, herbivorous species tend to have a slightly longer than average intestine. This is because plant foods need to go through a fermentation process to be fully digested. Therefore, it’s more efficient for their intestine to be longer.

4. Maintain compact sizes

Despite all the biological modifications that herbivorous birds have in order to digest their food, they’re not able to obtain many nutrients from their diet. Because of this, their bodies tend to be more compact because their maintenance requires fewer resources than those of a large specimen.

Types of birds with herbivorous diets

Within the group of herbivorous birds, there are also certain preferences in their diet, since everything depends on the needs and resources that exist in their own particular environment. This causes that several subtypes of these specimens can be distinguished, for example:

• Granivores: These feed on seeds or grains such as wheat, corn, or sorghum. In fact, they also often consume some stones to serve as additional crushers in their gizzard.
• Frugivores: Their diet is based on the consumption of fruits. Because this type of food isn’t as hard and is easier to digest, their beak and digestive system aren’t usually so modified.
• Nectarivores: Their tongue is adapted to eat the nectar produced by flowers, which is a substance rich in sugars. This type of food is usually consumed by species that have very high energy demands, as is the case of hummingbirds.
• Pollinivores: Certain birds tend to feed on pollen produced by flowers, since they contain nutrients and sugars that are “easy” to obtain.
• Muscivores: Certain species of trees produce an oily liquid inside their bark that has different functions. However, some birds take advantage of eating these substances because they usually contain minerals, sugars, and a lot of water.

Despite the existence of this classification, birds don’t always maintain a single preference in their diet. In some cases, they consume whatever resources are available in their environment, so they may change from being granivorous to frugivorous between one season and another.

Examples of herbivorous birds

If we want to be strict, there are few species of birds that have an exclusively herbivorous diet. This is because most get to consume animal protein, such as insects, on an occasional basis, which excludes them from the list. Therefore, the following examples contain some birds whose diet is mainly herbivorous:

1. European goldfinch (Carduelis carduelis)

This is a small bird with beautiful plumage that is characterized by its compact size, colorful plumage, and cheerful song. It has a granivorous diet for most of its life. However, it’s also capable of consuming small insects to supplement its diet, especially during the breeding season.

2. Hoatzin (Opisthocomus hoazin)

The hoatzin is a medium-sized tropical bird that lives in South America, which stands out for its peculiar “topknot” that protrudes from its head. To the naked eye it has a similar appearance to the galliformes, but with a more colorful and exuberant plumage. Its diet is based on the consumption of leaves, plants, and various types of fruits.

3. Parrots (Psittacidae)

Parrots are one of the most popular birds among bird lovers, as they have beautiful plumage and the ability to imitate the human voice. Of course, due to overexploitation of the species, many of them are illegal to keep in captivity. In the wild, these birds feed on seeds, fruits, and shoots, but also on insects and even carrion.

4. Sapsucker (Sphyrapicus spp)

Sapsuckers are close relatives of woodpeckers, so they share the typical behavior of pecking at trees to pierce their bark. As can be imagined, such behavior allows them to extract the sap produced by the tree and consume it.

5. Hummingbirds (Trochilidae)

These birds are famous for their compact size and their particular way of flying, which consists of flapping their wings at high speed. Because they expend a lot of energy to stay airborne, these birds require high-energy food such as floral nectar.

As you can see, birds are a pretty impressive group of animals. Each one of them has adapted in different ways to their environment, so it’s normal to see that they have different habits, behavior, and diets. However, this great variability is one of their most attractive features and the reason why they tend to attract our attention.