The San Diego Natural History Museum Birds Collection has grown into a major resource on bird species of western North America, including Baja California. Its taxonomic coverage includes 90% of the world's bird families, a coverage extended by the museum's status as a repository for specimens from the San Diego Zoo. The department produced the San Diego County Bird Atlas (http://www.sdnhm.org/science/birds-and-mammals/projects/san-diego-county-bird-atlas/), published in 2004 and based on field work from March 1997 through February 2002.