The adjective "herbivorous" (her-BIH-vore-us; rhymes with "deliver us" and "purr shiver us") describes a diet composed primarily of plant material which may include seeds, grasses, grain, buds, nuts, fruit, nectar, leaves, tubers, sap, pollen, and algae. While many birds include a variety of plant materials in their diets, to be considered herbivorous their diet must be mostly plant-based for much of the year.
Herbivorous Bird Diet
In the broadest sense, herbivorous birds eat plants, but there's much more to it than that. For a balanced, nutritious diet, most plant-eating birds eat a wide range of different plant parts, including tree buds, new leaves, and grass shoots, bits of bark, flowers, lichens, moss, nuts, fruit, seeds, sap, and more. Many birds that rely on plants for much of their diet will shift their eating patterns to consume plants or plant parts that are most widely available at different times of the year. For example, herbivorous birds may eat more buds and blossoms in spring, but shift to nectar or leaves in summer, fruit and nuts in the fall, and seeds throughout the winter.
There are several more specific herbivorous diets that describe dietary preferences that focus on just one part of a plant, including:
- Frugivorous: Fruit-Eating (apples, cherries, berries, bananas, citrus, etc.)
- Granivorous: Seed or grain-eating (wildflower seeds, birdseed, wheat, rice, etc.)
- Muscivorous: Sap-eating (sipping sap from trees)
- Nectivorous: Nectar-eating (sipping nectar from flowers)
- Palynivorous: Pollen-eating (from wildflowers or flowerbeds)
Many herbivorous birds also eat a substantial amount of grit, including rocks, sand, bits of gravel, or other coarse material. While these rough bits are not nutritious, they are stored in the bird's gizzard to help break down the tough fibers of plants for easier digestion.
While a herbivorous diet should be mainly plants, many plant-eating birds do occasionally eat other things. In particular, many herbivorous birds add a greater proportion of insects or other protein to their diet during the nesting season in order for their chicks to receive appropriate nutrition for healthy growth. As they mature, however, the young birds transition to a plant-based diet, and the adults return to their preferred plant foods.
Few birds are strict, consistent herbivores, but those that have largely herbivorous diets include the nene, snow goose, and other large waterfowl. The greater sage-grouse and other types of sage-grouse and related species are herbivores, as well as many parrots. The hoatzin is a tropical herbivore, and many smaller goldfinches are also largely plant-eating.
It is important to note that not every bird species that appears to be grazing or nibbling on plants may actually be herbivorous. Many birds, such as ibises, shorebirds, and wading birds will peck at the ground in search of worms and insects. Similarly, arboreal birds may seem to be nibbling at leaves or bark when they are actually foraging for insects.
Backyard Bird Feeding
It is easy to feed plant-loving birds in the yard, both with natural food sources as well as supplemental feeders. Popular options include:
- Planting fruit trees for birds as well as berry bushes birds can feast on. To tempt the greatest number of species, opt for several different types of fruit-bearing plants and choose varieties that yield ripe fruit at different times so birds have a steady food source.
- Create flowerbeds filled with seed-bearing flowers and allow the seed heads to ripen and dry on the stems so the seeds will be accessible to different birds. Smaller birds will cling directly to the flowers, while ground-feeding birds will forage underneath the plants.
- Plant top nectar-producing flowers for hummingbirds, and even consider creating a complete garden of nectar-rich blooms for hummingbirds. Remove flowers that hummingbirds don't like rather than wasting space with blooms they can't feed from.
- Offer different types of birdseed in feeders, choosing different feeder sizes and styles to accommodate different birds. Keep feeders filled and clean them regularly to avoid any problems with insect infestations or diseases in the yard.
- Use nectar feeders with a simple, classic nectar recipe to feed hummingbirds and orioles when flowers aren't blooming. Take steps to keep the feeders clean and discourage insects so birds can feed comfortably.
- Leave leaf litter intact during the fall and winter so birds can forage for seeds, nuts, and bits of plants leftover from earlier seasons. This will also help protect delicate plant roots for better growth the following spring.
- Minimize chemical use in the yard, particularly herbicides that would eliminate the very plants birds will rely on as natural food sources. Even so-called weeds such as dandelions can feed many different types of birds.