Nyjer seed, often mistakenly called thistle, is a tiny, black or brown seed imported primarily from Africa and India. This seed is highly prized by small finches like American Goldfinches because it contains approximately 40% oil, providing a rich source of energy. Because of this high oil content, Nyjer seed is susceptible to spoilage when exposed to moisture, warmth, or air over time. Feeding birds spoiled material can lead to illness.
Identifying Spoiled or Contaminated Seed
The high oil content makes Nyjer seed prone to rancidity and dangerous microbial growth. The most obvious sign of spoilage is the presence of mold, which often appears as white or green fuzzy patches. Mold causes the seed to clump together into solid blocks when moisture facilitates fungal growth, binding the seeds.
A rancid or sour odor is another clear indication that the seed is unfit for use. This smell results from the oxidation of the seed’s high-fat content, which breaks down the oils. The presence of insect pests, such as weevils or grain moths, also signals contamination and means the seed should be discarded.
Feeding birds spoiled seed carries significant health risks, particularly from molds. Fungi like Aspergillus can grow on damp or old seed, and when birds inhale the spores, they can develop Aspergillosis, a serious and often fatal respiratory disease. Even if visible mold is not apparent, excessive dust or fine powder at the bottom of a container can suggest degradation or the activity of pests. Any discoloration or change in texture is a sign that the seed’s quality has been compromised and should be replaced immediately.
Safe Disposal Methods for Unusable Seed
Once Nyjer seed is identified as spoiled, contaminated, or rancid, it must be disposed of in a manner that prevents harm to wild birds or the local environment. It is discouraged to scatter moldy seed on the ground or add it to a compost pile. Spores from molds, particularly the dangerous Aspergillus fungus, can survive and contaminate the soil, potentially infecting ground-feeding birds or other wildlife.
The safest method for disposal is to seal the unusable seed in a plastic bag and place it in the household trash destined for a landfill. Sealing the bag ensures that mold spores and insect pests are contained and cannot spread disease or infest other stored food.
If the seed is dry and only old or rancid, burning small amounts may be an option if local ordinances permit. However, the landfill remains the safest choice for disposing of spoiled Nyjer seed. This disposal process must also include raking up and discarding any spilled or moldy seed found on the ground beneath the feeder.
Extending Usability and Preventing Spoilage
The best approach is to prevent seed from spoiling through proper storage and purchasing habits. Nyjer seed will remain fresh for about six to twelve months when kept under ideal conditions. It is advisable to buy the seed in smaller quantities that can be used within a few months, especially during humid or warm weather.
Storing the seed in a cool, dry location is important because heat and moisture are the primary causes of spoilage. An airtight container, such as a metal bin or heavy-duty plastic tote with a tight-fitting lid, will prevent air exposure, moisture infiltration, and pest infestation. Keeping the container off the ground and in a stable environment, like a garage or utility room, helps maintain consistent temperature and humidity levels.
For seed that is only slightly old but not moldy or rancid, simple stirring can sometimes break up minor clumping and refresh the material. If longer-term storage is necessary, placing the seed in the freezer can significantly extend its freshness by slowing the oxidation of the oils. When filling feeders, only add a small amount of seed that birds can consume quickly, ensuring the food offered remains fresh.