What Do Cardinals Eat? | Diet of Wild & Backyard Birds

Northern Cardinals eat mostly seeds and fruit, plus insects that are vital for nesting season and for feeding their young.

If you’re wondering what to put in your feeder — or what a wild cardinal finds on its own — the answer starts with seeds and fruit, then shifts to protein when chicks arrive. The northern cardinal is an omnivore whose diet flexes through the year. Understanding that seasonal swing is the difference between a yard cardinals visit and one they ignore.

What Do Cardinals Eat in the Wild?

Cardinals forage mostly on the ground and in low shrubs, where they find seeds, fruits, and insects. Their natural menu includes grape and smartweed seeds, beetle larvae, grasshoppers, crickets, and katydids. They also eat mantises — a protein source most backyard birds skip.

That insect-heavy list matters more than most people realize. During breeding season, insects become the main food for nestlings; parent cardinals need the extra protein too. Birds of the World’s species account confirms: insects matter most in spring and summer, while fruits and seeds dominate in fall.

What Do Cardinals Eat at Feeders?

Black oil sunflower seeds are the single best choice for cardinals. They also reliably eat striped sunflower seeds, sunflower chips, safflower seeds, peanuts, cracked corn, and suet. Audubon’s guide to attracting cardinals highlights sunflower seeds as the top draw at feeders.

One detail to know before you buy seed: cardinals are larger perching birds, so they struggle with small tube feeders designed for chickadees and goldfinches. Hopper feeders and open platform trays give them room to land and eat comfortably. A platform feeder with black oil sunflower seeds is the easiest way to get cardinals into view.

If you’re looking for the best seed mixes and feeder options that cardinals actually eat, see our tested cardinal bird food picks — we compared the top blends for seed quality and value.

How a Cardinal’s Diet Changes by Season

Cardinals don’t eat the same thing year-round, and that’s a point the sources stress. In fall and winter, seeds and fruits carry them through. As breeding season begins, their diet shifts toward insects — which provide the protein nestlings need to grow.

It’s a common mistake to assume seeds alone cover a cardinal’s needs. A feeder full of sunflower seeds is great for winter, but in spring and summer, cardinals in your yard are also hunting insects to feed their young. Consider suet and mealworms as spring supplements alongside your seed.

The University of Florida’s cardinal guide reinforces that a varied diet is key — cardinals thrive when they can pick from natural foods, not just whatever’s in the feeder.

FAQs

Do Cardinals Eat Suet?

Yes, cardinals visit suet feeders, especially in colder months when they need extra calories. Suet provides a concentrated source of fat that helps them maintain body heat in winter. Offer suet cakes in a cage-type feeder or spread suet on a platform tray, since cardinals prefer a flat surface to land on while eating.

What Seeds Attract Cardinals Most?

Black oil sunflower seeds are the most attractive seed for cardinals, followed by striped sunflower seeds, sunflower chips, and safflower seeds. Cracked corn and peanuts also draw them in. Safflower is a useful option because squirrels and many other birds dislike it, giving cardinals a quieter place to eat.

Do Cardinals Eat Insects or Just Seeds?

Cardinals eat both. While seeds and fruit form the base of their diet, insects are essential during spring and summer breeding season. Beetles, grasshoppers, crickets, and caterpillars provide the protein needed for egg production and for feeding nestlings, which rely almost entirely on insects in their first weeks.