Thousands of ducks flock to Lake Lanier each spring. Well, they don’t really flock as much as they get shipped to Gainesville then pushed off a barge into the lake. It’s all in an effort to raise money for the Boys & Girls Clubs of Lanier during the annual Rubber Duck Derby, and this year’s derby marks the 20th anniversary. It will take place at 2:30 p.m. Saturday, May 5, at Clarks Bridge Park.