A Nauru Airlines Boeing 737-300 on behalf of Qantas, registration VH-VLI performing flight QF-7332 from Brisbane,QL to Townsville,QL (Australia), was climbing out of runway 19L when the crew reported they had gone through a flock of birds upon rotation. The aircraft stopped the climb at 10,000 feet. A runway inspection revealed 8 to 10 dead birds on the runway at about the location where the aircraft had rotated. The aircraft entered a hold at 10,000 feet to burn off fuel and returned to Brisbane for a safe landing on runway 19L about 70 minutes after departure.