The Western Bluebird is a year-round resident of San Diego County, California. And between late March and August, they will nest and rear their young. The Western Bluebird is a secondary cavity nester, traditionally using holes in trees, usually excavated by woodpeckers. However, they will readily use a nestbox designed for bluebirds.
The Western Bluebird is common in pine and oak woodland in the inland valleys, foothills, and mountains of San Diego County. Recently the species has turned an evolutionary corner and is becoming an urban adapter in our area. The San Diego Natural History Museum first noticed this when doing field work for the San Diego County Bird Atlas in the late 1990's, and the trend has accelerated ever since. The birds are apparently following in the wake of Nuttall's Woodpecker, an earlier urban adapter that took advantage of the extensive planting of trees over what was once treeless sage scrub.
Western Bluebirds are fascinating, lovely songbirds. To attract them you will need to put up a nestbox specifically designed for Western Bluebirds in the appropriate location and monitor it. You may also need to supply water and protect the birds from pests. You'll find information about how to get started with Western Bluebirds (and more) in the links on the left.