Figure 3: a) Nard Speaker and amplifier used to playback distress calls and non-distress (acoustic control) call from the ring billed gull (Larus delawarensis) from June 16 through July 30, 2012. b) Deployment of laser in zig-zag pattern based on previous pilot results. Black dot refers to observer using red laser and flashlight controls, open dot represents observer position using green laser.