White-crowned Sparrow in Imperial Beach

Most of the White-crowned Sparrows in San Diego are the pale-lored* and bright clean plumaged Gambel's form, Zonotrichia leucophrys gambelii. They nest in southwest Canada and southern Alaska and migrate farther south for winter than the Puget Sound White-crowned Sparrows, Z. l. pugetensis (breed in Pacific Northwest and migrate to central California) and the mostly non-migratory Nuttall's White-crowned Sparrow, Z. l. nuttalli (residents in central coastal California).

When more northerly-breeding populations migrate farther south than those breeding in middle latitudes (relatively speaking) this is called "leapfrog" migration. Fox Sparrow populations in western North American also do this.

The pale lores and orangish bill help identify the Gambel's White-crowned Sparrow.

In laurel sumac bush. Imperial Beach, California. January 20, 2019. Greg Gillson.

Some dark-lored Mountain White-crowned Sparrows, Z. l. oriantha, breeding in the interior mountains of the western United States. A few of these sometimes reach southern California in winter.

* Lores (usually used as a plural) are the feathers in the region of the face directly between the eye and bill.

More photos of White-crowned Sparrows in San Diego from eBird. Click on the photos to rate (1 awful, 2 poor but identifiable, 3 average or small, 4 very good, 5 magazine cover worthy).