The question of whether squirrels consume Nyjer seed, often mislabeled as thistle seed, is common among backyard bird enthusiasts looking to protect their feeders. Nyjer seed, which is a tiny, black seed from the African yellow daisy (Guizotia abyssinica), is a highly nutritious food source for small finches. Squirrels generally avoid these seeds, though the answer is not an absolute denial.
Squirrel Preference for Nyjer Seed
Squirrels are opportunistic feeders, meaning they will sample a wide variety of foods based on what is readily available in their environment. However, Nyjer seed is typically not a preferred item in their diet. Squirrels generally favor larger, higher-fat foods that offer a greater caloric reward for the effort involved in consumption, such as sunflower seeds, peanuts, and corn.
Compared to preferred foods, the small shape and quantity needed to satisfy a squirrel make Nyjer seed an inefficient meal. Feeders containing only Nyjer seed are often left alone, unlike those filled with more desirable seeds. Squirrels may only attempt to eat Nyjer seed if other, more appealing food sources are scarce or completely unavailable.
Physical and Nutritional Reasons for Rejection
The term “thistle seed” is a common misnomer for Nyjer seed, which comes from the Guizotia abyssinica plant, not the true thistle plant (Cirsium or Carduus species). The seeds are tiny, resembling miniature rice grains, and are best dispensed through specialized feeders with small ports.
A significant factor in the squirrel’s rejection is the effort-to-reward ratio. Although Nyjer seed is approximately 35% fat and 18% protein, its small size requires a squirrel to spend excessive time and energy to consume a sufficient quantity. This makes it a poor investment compared to cracking open a large peanut or sunflower seed. Furthermore, the seed’s taste and smell are generally considered unappealing to squirrels, contributing to their low interest.
Deterring Squirrels from Bird Feeders
For the rare occasions when a squirrel does attempt to raid a Nyjer feeder, simple physical and management strategies can be highly effective. Weight-activated feeders are one method, as they are designed to close the feeding ports under the weight of a squirrel or other larger animal. Using feeders specifically designed for Nyjer seed, which often feature very small openings, can also prevent larger animals from accessing the food.
Strategic placement of the feeder is also highly beneficial for deterring squirrels. Feeders should be placed at least ten feet away from any structure or tree that a squirrel could use as a launching point to leap onto the feeder. Installing a wide baffle, which is a dome or cone-shaped barrier, on the pole beneath a feeder can prevent squirrels from climbing up to reach the seed. As an alternative, adding capsaicin, the compound found in chili peppers, to bird seed will deter squirrels, as mammals are sensitive to the spicy flavor while birds are not affected.