Byrd, 34, has started the season in sluggish fashion, posting a .075 batting average (3-43) in 13 games. Tony Campana, who was recalled from Triple-A Iowa today, will help take Byrd's role in centerfield.
Bowden, a supplemental round selection (47th overall) by Boston, is a native of Winfield, Ill., and attended Waubonsie Valley High School in Aurora, Ill. The 6-foot-3, 215-pound pitcher spent the last three seasons moving between Boston and Triple-A Pawtucket, where he played the majority of the 2011 season.
This is the second transaction between the Cubs and Red Sox since Theo Epsetin, Boston's former general manager, became Chicago's president of baseball operations. In March, the Cubs moved Chris Carpenter and a player to be named later to Boston as compensation for Epstein's departure.