Date of this Version
Gull numbers roosting at two waterbodies close to a military airfield in central England were monitored at dusk and dawn for four weeks during November 2006. Approximately 25,000 and 8,000 gulls were present at each site respectively. Two LEM 50 laser torches mounted on tripods were then deployed to disperse the roost at one of the sites. No effect was observed before dusk or after dawn. Beams were scanned approximately 0.5 to 1metre above the surface of the water across an arc of approximately 200o during a three minute period. The process was repeated continuously for one hour from dusk. Gulls were successfully dispersed and left the site. Large numbers were still present, however, by dawn on all following mornings. Deployment rates were increased, firstly to include three equally spaced deterrence sessions per night, then subsequently to scans every half hour throughout the night. Gull numbers were reduced to zero overnight with none present at dawn. Numbers increased at the alternative waterbody. Birds continued to arrive before dusk to roost and dusk dispersal was always required. The technique cleared all gulls whenever it was deployed but could not eliminate the arrival of birds that would attempt to roost each afternoon.