White-crowned Sparrows are a common sight in Oregon, both as migratory visitors and, in some coastal populations, year-round residents. When it comes to distinguishing between males and females, the key characteristic to remember is that adult male and female White-crowned Sparrows look essentially alike in their plumage.

Overall Appearance (Both Sexes):
Size and Shape: They are relatively large sparrows, measuring around 6-8 inches in length, with a small bill and a long tail. Their head can appear peaked or flat depending on their posture.
Head Pattern: This is their most distinctive feature. They have a bold, contrasting black and white striped crown. There are black stripes on the sides of the crown and a white stripe down the center, flanked by white "eyebrows" above a black eye-stripe.
Bill: Their bill color can vary from yellowish to orange or pinkish, depending on the subspecies and individual. In Oregon, you might encounter birds with yellow bills (common in Pacific Coast populations) or pinkish/orange bills.
Body: They have a gray breast, dull brown upperparts with streaking, and tan-washed underparts. They typically have two white wing bars.
Legs: Their legs are usually pinkish to yellowish.

Key Points Regarding Male and Female Distinction in Oregon:
Plumage: As mentioned, adult males and females have the same striking black and white head pattern and overall body coloration. You cannot reliably determine sex by plumage alone in adult White-crowned Sparrows.
Size (Subtle Difference): While not noticeable in the field, males, on average, are slightly heavier and have longer wings than females. This difference is usually only detectable when birds are banded and measured by researchers.
Behavior (Breeding Season): During the breeding season, males arrive on nesting grounds before females and establish territories by singing. Females are responsible for building the nest and incubating the eggs. Both parents feed the nestlings. While females rarely sing, they may sometimes do so to defend a territory or food source.
Subspecies Variation: Oregon is home to several subspecies of White-crowned Sparrows, and there can be subtle variations in bill color (e.g., yellowish on coastal populations, pinker/orange on others) and the extent of the lores (feathers between the bill and eye) among these groups. These variations are not sex-specific.

Immature Birds:
First-year White-crowned Sparrows have a duller appearance. Instead of the crisp black and white crown stripes, they will have brown (rufous-brown to rich dark brown) and creamy stripes on their head. They are also generally browner on the back and underparts.