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Wildlife Protection

Keeping It Simple: Easy Ways to Help Wildlife Along Roads

Insulation fabric and plastic drainage covers protect migratory birds from bridge-construction disturbance

Pigeon guillemots and rough-winged swallows - two species protected by the Migratory Bird Treaty Act - like to nest in the hollow undersides of bridges beside drainage "weep holes." So before the nesting season and scheduled construction on two bridges, California Department of Transportation contractors took these easy steps to protect the birds: To deter pigeon guillemots from nesting on the Noyo River Bridge near Fort Bragg while a new bridge was being built around the existing bridge, they plugged the weep holes with fiberglass insulation material. To keep rough-winged swallows from nesting on the American River Bridge near Sacramento during hinge-replacement work, they plugged the holes with removable plastic drainage covers. In each case, the birds were well protected from all construction disturbances - and with minimal effort and expense.
--Apr 25, 2003

Tim Ash, (707) 445-6420 or

Northern Rough-winged swallow
Photo by W. D. Curtis ©
Northern Rough-winged swallow

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On or Near Bridges - California
Updated: 12/12/2012
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