On Riverside County, California's Pal Verde Bridge (a State Route 78 bridge scheduled to be demolished and replaced), Caltrans crews are successfully keeping migratory cliff swallows away from future construction activity using the same kind of bird-netting material commonly placed over fruit trees. The crews wrapped and securely taped the material around the bridge abutments and underneath the bridge deck where cliff swallows used to build their nests. Every few feet, wood-frame blocks (1"x12") were nailed to the edges of the netting material to further secure its placement. The exclusionary netting materials have been strong enough to prevent swallows from returning to the Palo Verde Bridge for the past several years. Since demolition of the old bridge has been delayed, the exclusionary device has also saved time and money by making it unnecessary for Caltrans crews to re-visit the bridge to remove abandoned cliff-swallow nests. As for the cliff swallows...they're resilient and resourceful. The birds have flown to other locations nearby to build their nests.
--Mar 23, 2009
|Photo by Photo by M. Sadeghi.|
|The netting being installed here will keep cliff swallows away from bridge-|