The Northern Cardinal (Cardinalis cardinalis) is one of North America’s most recognizable songbirds, known for its vibrant color and distinct song. These birds are frequent visitors to backyard feeders, leading many people to observe their feeding behaviors closely. The nature of their diet is often more complex than casual observation suggests, prompting questions about what they eat in the wild.
Are Cardinals Predators?
The short answer is that Northern Cardinals are not true predators of other birds, including nestlings. They are scientifically classified as omnivores, with a diet that leans heavily toward plant matter, making them primarily granivores, or seed-eaters. The widespread idea that cardinals habitually prey on the young of other species is a myth or a significant misinterpretation of their behavior.
In extremely rare instances, an individual cardinal might opportunistically scavenge on a deceased or critically injured bird, but this is an isolated occurrence, not a standard predatory behavior. The powerful, cone-shaped beak of the cardinal is perfectly adapted for crushing seeds, not for tearing flesh or actively hunting vertebrate prey. They generally pose no threat to the nests of other songbirds.
The Typical Cardinal Menu
The Northern Cardinal’s diet consists overwhelmingly of plant-based materials throughout the year. Their favored food source, especially at feeders, is seeds, with black oil sunflower seeds being a particular favorite. They use their strong, thick beaks to effectively crack the hard shells of these seeds, accessing the nutritious kernels inside.
Beyond seeds, they consume a wide variety of wild fruits and berries, which provide necessary moisture and carbohydrates. Common plant foods include the fruits of dogwood, wild grape, mulberry, and sumac. They also forage for leaf buds and flower parts, sustaining them outside of the breeding season.
High-Protein Needs During Nesting
The period when cardinals are most often observed consuming animal matter is during the spring and summer breeding season. Although adult cardinals primarily eat seeds, their nestlings require an extremely high-protein diet for rapid growth and development. This protein is supplied almost exclusively in the form of invertebrates.
Parents intensely forage for soft-bodied creatures like beetles, spiders, grasshoppers, snails, and various caterpillars. This insect-heavy diet provides the young with the protein and moisture they need to survive and fledge quickly. Both parents ensure the nestlings grow from hatching to fledging in about ten days.
This intense, protein-focused foraging is the likely source of confusion, as observers see cardinals actively hunting for animal life. The sight of a cardinal aggressively pulling a large caterpillar from a branch is sometimes mistakenly interpreted as a threat to a bird nest. This insectivorous phase is a temporary, yet vital, requirement for successfully raising their young.