According to a report from the Los Angeles Times, Caltrans draped the netting over the Petaluma and Lakeville Overpass bridges on Highway 101 to keep cliff swallows from nesting beneath the bridges.
Swallows migrate about 6,000 miles each Spring from South America to nest near the Petaluma River. They have been known to build as many as 500 nests beneath the bridges.
But the netting did a lot more than that. The netting “entangled, maimed and killed” more than 100 cliff swallows during the 2013 nesting season, according to a lawsuit filed against Caltrans and the Federal Highway Administration by the nonprofit group Native Songbird Care and Conservation.
The lawsuit accuses the two agencies of violating the National Environmental Policy Act and the Migratory Bird Treaty Act.
As part of the settlement, Caltrans also agreed to use materials such as plywood and vinyl to keep the swallows from nesting in construction zones on the bridges for the 2014 nesting season. Caltrans also agreed to pay for educational programs about birds’ nesting behavior.