The birth rate in the Sacramento region - and across California - continues to plummet, leaving several local communities with few children and posing new challenges for school districts.

About 27,000 babies were born to parents living in the four-county region during 2015, for a rate of 12 births per 1,000 residents. The region's birth rate has fallen by 20 percent in the last decade.

In the Sacramento region, birth rates are lowest in suburban areas where families have relatively high incomes. Less than 4 percent of residents in Davis and Granite Bay are under 5 - among the lowest rates of children in the state, census figures show.

The highest birth rates are in relatively poor areas. About 9 percent of residents in unincorporated south Sacramento are below the age of 5.

The trend has consequences. Davis schools are accepting hundreds of students from nearby communities to keep enrollment steady. The Eureka Union School District in Granite Bay has seen enrollment fall by 20 percent in the last decade.

This map shows, by census tract, the neighborhoods with the lowest proportion of residents under age 5. For comparison purposes, click on the "1970" tab to see the same breakdown 50 years ago.