An adult bird bearing food in its bill plunged into the willow just as another adult departed. A flutter of wings and more commotion ensued as four youngsters vied to lay claim to the newly fetched prize. To my surprise, I noticed that juvenile white-crowneds, unlike immature birds seen in winter through much of the continent, display heavy streaking on their chest and flanks. I attended to their goings-on for several minutes, and remained, for the entire time, delightfully oblivious to the soggy condition of my person. Although nestlings and dependent young receive a diet composed mostly of insects, the diet of adult birds skews heavily toward seeds and other plant material.
Young birds begin foraging on their own somewhere between two and three weeks of age.
They do not, however, become fully independent of their parents until about one month after hatching. It should come as no surprise that white-crowneds frequently build their nests on the ground. Ground nests hold heat better than nests constructed among branches a few inches or feet above the ground, and therefore allow for lower energy expenditures by incubating birds. Even so, late spring and early summer snowstorms represent a leading cause of nest failure among white-crowneds. Ideal breeding habitat for all races occurs near a source of water.