This species has expanded in recent decades into urban areas such as San Francisco where it is now one of the most common 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 are cross-hatched and tail more adult-like with broader dark bars as seen here. Canon PowerShot SX50 HS.