This species has expanded into the San Francisco Bay Area where it is now one of the most common breeding raptors. It is often detected by its loud screams which carry considerable distance. This is the West Coast subspecies B. l. elegans which is smaller and brighter than Eastern subspecies. Also the juveniles are very different, with much more spangling on the back and wing coverts on elegans cf. nominate lineatus. Its juvenile underparts include cross-hatching as seen here.