When standard solutions to keeping cliff swallows off bridge-construction sites could not be installed on a bridge in Fresno County, California, California Department of Transportation (Caltrans) staff used their ingenuity and some hardware items on hand to protect the migrating birds and keep the State Route 41 Overpass project moving. Bridge crews used contact cement to attach clear vinyl plastic sheeting to the bridge columns to form a series of temporary barriers. Bridge vents were blocked using hardware cloth, successfully excluding swallows without disturbing air-flow. The plastic sheeting solution cost Caltrans only $2,000 to buy and install.
--Mar 23, 2009
|Photo by Photo by Caltrans|
|Plastic sheeting was more effective than standard cliff-swallow netting on this bridge.|