This particular species of bird is very easy to recognize because of its fairly limited variation of plumage. Both males and females have two distinctive black stripes that extend along the crown of the head and behind the eyes, which boldly outlines the solid white feathers on its head. The white-crowned sparrow has a solid light gray breast and dark brown flight feathers. The coverts are each tipped with a white band. Though juveniles have very similar plumage, they tend to be more brown (instead of gray) and the head has brown, not black, stripes that surround a slightly darker "white" patch. There is no seasonal variation in Zoneotrichia leucophrys' plumage, but there has been geographical variation noted (Chilton et al. 1995).
The body mass of males tends to be slightly higher than females throughout the year. During the summer, the average weight of males is 28.27g for males, while it is about 25.47g for females (Chilton et al. 1995). Both sexes' mass, however, decreases at the beginning of the breeding season (more so in females), and increase by that same amount at the start of winter (Chilton et al. 1995).
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Average mass: 25.82 g.
Average basal metabolic rate: 0.336 W.