Some of the native local backyard species in the Sacramento area that take well to nest boxes are Tree Swallow, Oak Titmouse, White-breasted Nuthatch, Bewick's Wren, and House Wren. If you are lucky you could get an Ash-throated Flycatcher. In some areas you may get Western Bluebirds, especially sites adjacent to the American River Parkway and moving up into the low foothills. In a larger box, you could, with a lot of luck, get a Western Screech-Owl. In areas adjacent to open grassland you could get Barn Owls (in a very large box) and American Kestrels, and in riparian areas Wood Ducks readily use nest boxes. Additionally, Northern Flickers sometimes use larger nest boxes, like those designed for Wood Ducks, and also have the disagreeable habit of burrowing into the sides of houses, especially to roost in the winter.There are two non-native species that will use nest boxes, but should be discouraged. European Starlings (http://www.allaboutbirds.org/guide/European_Starling/id) aggressively compete with native birds and are likely a major cause of the widespread decline of bluebirds in North America (http://www.natureali.org/european_starling.htm). Another non-native species is the House Sparrow (http://www.sacramentoaudubon.org/clhousesparrow.html), which also competes with native species, but is typically restricted to human habitations, and isn't as widespread in wild areas as the starling. Boxes designed for the smaller species (the first seven listed above) have an opening too small for use by a starling. If House Sparrows begin using the boxes, it is best to close them (cover the opening) if it looks like they are going to take up residence. While watching the birds using your nest boxes can be very rewarding, there can also be work and disappointment involved. It is best to clean out old nest material at the end of each nesting season and make any necessary repairs to the boxes. You may also need to replace or shore up the doors or openings, as woodpeckers and, sometimes, rodents will enlarge them, making them suitable for starlings. Occasionally paper wasps will build nests in the boxes that must be dealt with, or at least avoided. It is not legal to destroy eggs of native birds, but you may remove eggs of the non-native species. It is also important to be aware that your favorite nest may fail for various reasons and you could find that the eggs didn't hatch or the chicks have died, often for no obvious reason (it can be difficult to accept, but it is good to be philosophical about these losses--if every pair of birds had all of its several chicks survive each year, there would soon be more birds than food or habitat for them).