What is the primary preference displayed by White-crowned Sparrows when selecting seeds during their non-breeding season diet?

Seeds of grasses and weeds

When seeds constitute the primary dietary staple for the White-crowned Sparrow, particularly during late fall and winter, their selection is generally opportunistic, though a clear preference exists. They exhibit a leaning toward the seeds produced by native grasses and various weeds. These food sources are typically abundant and readily available on the ground during the colder months, often accessed by walking through leaf litter and debris. While they might consume small grains or sunflower fragments, the foundational element of their preferred seed diet consists of these naturally occurring grass and weed seeds, which provide the necessary balance of carbohydrates and fats for survival.