The vineyard crew was hard at work on the grounds of B Wise Vineyards in Sonoma Valley on Friday morning.

But they weren't picking grapes.

Instead, the seasoned crew of vineyard workers were tackling landscaping projects: installing a switch in a lawn irrigation system, planting trees and spreading fertilizers. On other recent days, they cleaned pools, cared for avocado trees and tended to the bees and chickens on the property.

Fewer workers are migrating from Mexico, and the number of people leaving the U.S. for Mexico now outpaces the number of those coming in, according to a report by the Pew Hispanic Center.

From 1995 to 2000, nearly 3 million people migrated from Mexico to the United States, while only 670,000 left, according to Pew estimates. But from 2005 to 2010, only 1.37 million came into the U.S. from Mexico, while a larger number, 1.39 million, returned.

For more, see: Decline in immigration felt in vineyards