Last updated: 18 December 2023
As you can imagine, with over 10,000 species of birds in the world, the diets and what they eat vary tremendously. But which are birds omnivores?
Many species of birds are considered omnivores, including crows, ducks, thrushes, blackbirds, woodpeckers, orioles, cranes, pheasants, gulls, robins, starlings and chickens. These birds have highly varied diets, which depend on what food sources are available in and around their habitat.
While the list of birds above is considered omnivorous, some of them are stronger omnivores than others. However, they are all not fussy and will eat a mixture of plant-based and animal-based foods.
Woodpeckers are strong omnivores
Omnivore is the term given to animals and birds with a diet that regularly includes significant amounts of plant-based and animal-based food. The adjective to describe these animals and birds is omnivorous.
The diet of an omnivorous bird can be highly variable and can depend on the abundance of certain food sources within both their range and habitat.
To be considered omnivorous, birds do not need to eat every single type of plant or animal food. However, the diet does need to contain significant amounts of both animal and plant-based foods.
Classification of diets is usually only done when birds reach their adult stage, as both the chick and juvenile stages of their lives may eat significantly different diets. This is because younger birds depend on foods rich in nutrients and proteins, which helps with growth and development.
Nuthatch feeding hungry nestling (chick) caterpillars
Technically speaking, most birds could be considered omnivores, as most birds consume insects as part of their diets, as they provide reasonable amounts of protein.
However, birds that only eat a small portion of insects and other animal materials and have a diet that mainly comprises plant-based things are generally not classified as omnivores.
Birds generally classified as omnivorous have more of an equal balance between the amount of plant-based and animal-based foods consumed in their diet.
Examples of birds that are considered omnivorous include:
Omnivorous birds have to change their diets primarily down to the time of year and what food sources are available.
This means that insects can be the primary source of food during spring and summer, as the insect populations are booming and there are plenty around.
When summer is starting to come to an end, insect populations can begin to decline, and instead, omnivorous birds often feed on fruits that are now more readily available as the crops ripen. During fall, both grains and seeds may also be consumed more regularly, as they are generally more available.
During winter, omnivorous birds become less fussy and will eat most things that can, as food can be scarce during this time. Many birds can store foods such as grains and seeds for this time.
The highly variable diet and adaptability of omnivorous birds mean they generally have a greater chance of survival, as there's a broader choice of food they can and will eat. This is much more apparent for species of birds that are resident and do not migrate during the colder winter months.
Crows foraging for seeds in a field, during winter
Not only the weather determines what omnivorous birds eat as, during the breeding season, female birds often consume foods that contain more calcium. This is because it promotes the healthier development of their eggs.
When birds are moulting, more animal-based foods can be consumed, as the higher levels of protein and nutrients greatly assist the development and growth of new feathers.
Birds that are migrating require diets high in calories and fats, both before and during migration. This extra energy is crucial to allow the birds to complete long-distance migrations successfully.
Chicks and Juvenile birds often have diets where they eat more animal materials. This is because high levels of protein and nutrients are required for growth and development at such a crucial point in their lives.
Omnivorous birds reaching more mature parts of their lives often switch their diets to become an entirely herbivorous diet, as they don't rely on as much protein and nutrients daily. At this point, they technically wouldn't be considered omnivorous anymore.
Because of the varied diet birds have, this means having a mixture of both animal-based and plant-based foods placed on your feeder will cater to all species and attract a more diverse collection of hungry birds.
Animal-based garden bird foods include mealworms, crickets and anything, including fat-based suet. Minimising the number of pesticides and insecticides will mean that there is an abundance of insects and rodents for birds to hunt and feed on.
Some examples of plant-based backyard bird foods include seed mixes, sunflower seeds, niger seeds, peanut butter, pieces of fruit, sugar or nectar water, berry bushes, fruit trees, seed-bearing flowers and pumpkin seeds.
Keeping your feeders stocked with a mix of the above will not only supply birds with a great source of food but will also attract more diversity in the species of birds in your backyard.
Having many different types of feeders helps attract more birds, too, as different styles of feeders are more accessible than others for specific birds.
Ensure that feeders are regularly cleaned to stop the spreading of any disease and make them less attractive to rodents and pests. Also, consider installing baffles to keep unwanted visitors away.
Birds feeding on a selection of food in winter
Different bird feeders attract different birds
Eagles are not omnivores and are instead generally classified as carnivores, and this is because their diets consist mainly of primarily other animals. Eagles will only eat plant-based vegetation to prevent starvation or help with digestion; however, this is very rare.
The majority of owls are carnivorous and have diets that mainly consist of small mammals, including mice and rabbits, lizards and snakes. There are a few exceptions to this rule, where smaller owls like the burrowing owl, who on occasion may also consume seeds and fruits.
Owls will rarely consume vegetation, and when they do, it is usually in the act of desperation to prevent starvation, where there is no other food around. It can also be to help with digestion too, but this is reasonably unusual behavior.
Birds of prey are not omnivorous and, instead, are all classified as carnivorous. This is because the majority of the food they predate and consume is the meat of other animals. Most birds of prey will hunt and eat reptiles, mammals, other birds and fish for their diets.
Technically birds can be either herbivores, carnivores and omnivores. Birds that consume only plant materials (like hoatzins) are classified as herbivores, birds that eat a mixture of plant-based and animal-based (like crows and many others) are omnivores, and birds that only eat meat (like owls, eagles and hawks) are classified as carnivores.