Pigeons have been using the underside of a listed bridge in Cambridge as a roost. Sluice gates are located under the bridge to control water levels on the River Cam. The roosting birds have caused the control gates to become covered in bird droppings, which has created problems for the maintenance teams. Not only are the deposits unpleasant to work in but they also present the risk of infection (Psittacosis) for the maintenance operatives.
Previous attempts to prevent roosting, by fixing wire mesh and Perspex screens to the underside of the bridge, have not proven successful and have actually increased the roosting potential above the sluice gates. Birds have also become trapped between the mesh and the bridge as access holes had not been fully closed off.
Due to the sensitive nature of the surrounding area, a low-impact solution for deterring pigeons from roosting under the bridge was devised that would cause no harm to the pigeons.
CGM Group were tasked with the removal & disposal of the existing Perspex screens, and removal of the wire mesh under the bridge to enable a thorough cleansing of the structure and service walkways. Once the structure had been cleansed the wire mesh was replaced under the bridge and all possible access points for the pigeons closed off. New, custom-fit Perspex panels were then snugly fitted on the underside of the mesh. As well as preventing potential pigeon roosts, this also prevents detritus from falling from the walkway above onto maintenance operatives below.
The City Council would not sanction the use of bird strips on any possible roosting ledges, as it was perceived that this would be visible to members of the public in a high-profile tourist area. Bird repellent gel was therefore applied to the structure to maintain the aesthetics of the listed bridge, but deter the pigeons from using the bridge & sluice structure as roosts.
Following this major piece of specialist environmental work, the client praised CGM Group for the innovation and the quality of our work.