Tree Swallow - Tachycineta bicolor
|Chicks at birth||
|IUCN Conservation Status||
The Tree Swallow breeds in North America including the S.F. Bay Area. They winter in Mexico, Central America and the Caribbean.
The best place I know to see them is Coyote Hills Park in Fremont, CA. They have set up nesting boxes along some of the paths which the swallows use. They primarily eat insects.