Feeding wild birds is a rewarding backyard activity, and nuts are a popular high-energy food choice. Walnuts are acceptable for many bird species, but offering them safely requires careful attention to preparation and presentation. Understanding the nutritional benefits and safety risks ensures a healthy treat for visiting wildlife.
Nutritional Value and Safety Considerations
Walnuts are a concentrated food source, providing healthy fats, protein, and micro-nutrients. Their high caloric density is valuable during winter or migration, supplying necessary energy for body heat and long flights. Omega-3 fatty acids contribute to cell membrane health and vibrant feather quality.
The most serious safety concern is contamination by mold and fungi. Aflatoxins, produced by the Aspergillus flavus mold, can be lethal to birds, primarily targeting the liver. Proper storage is paramount: nuts must be kept dry and cool, and moldy nuts must be discarded immediately. Always source nuts from a reputable supplier who tests for aflatoxin levels.
Never offer birds walnuts that have been salted, roasted with oil, or seasoned, as the sodium content is highly toxic. Ingestion of excess salt can quickly lead to dehydration, kidney failure, and neurological damage. Unshelled walnuts should be avoided for most small species, as the hard shell can be difficult to manage and may pose a choking hazard. The shell can also trap moisture, accelerating mold growth.
Preparation and Presentation Methods
Walnuts must be offered shelled and broken down into small pieces for accessibility and safety. The ideal size is roughly pea-sized or smaller, preventing small birds like chickadees and titmice from swallowing pieces that are too large. Crushing the nuts also allows birds with weaker bills to access the interior.
Use only plain, unflavored walnut kernels; nuts with sugar, honey, or artificial flavorings are inappropriate. While the natural oils can sometimes clog traditional tube feeders, walnuts are suited for open feeding styles. Platform or tray feeders are the most effective way to serve chopped walnuts, as their open design allows multiple birds to land and forage easily.
Ground-feeding birds, such as doves and towhees, will readily consume scattered pieces. Only put out a small amount of walnuts at a time—enough to be consumed within a day or two—to prevent spoilage and discourage rodents. Placing walnuts in a mesh wire feeder is another option, which forces birds to peck off small fragments rather than carrying away large pieces.
Walnut-Loving Bird Species
Walnuts attract species with bills adapted for handling or breaking hard items. Larger members of the Corvid family, such as Blue Jays, Steller’s Jays, and Crows, eagerly consume walnut pieces. These strong-billed birds often empty a feeder by carrying multiple pieces away in their throat or bill.
Smaller, acrobatic species also prefer crushed walnuts due to the energy they provide. Common visitors include:
- Nuthatches
- Titmice
- Chickadees
- Woodpeckers (Downy and Hairy)
These smaller birds typically take a single piece and fly off to a secluded location to consume it. Woodpeckers are attracted to the high-fat content and will hammer at the nuts to break them into smaller portions.
The high-fat content makes walnuts favored by caching species like Jays, Nuthatches, and Chickadees. Caching is the behavior where birds hide individual food items in locations like tree crevices or the ground for later retrieval. Providing walnuts assists these birds in building crucial food reserves that help them survive periods of food scarcity.