Barn Owls are only one of many important species threatened by the use of anticoagulant pesticides (a MDAS conservation concern), which can kill predators that eat rodents carrying these compounds.
Not only have dead trees and other sources of natural nest cavities been removed by rapid development, but the many agricultural barns which used to support a healthy Barn Owl population have been disappearing from our area as the farms and ranches have been replaced by subdivisions and shopping malls.
The numerous owls, which used to help control rodents such as gophers, rats, and mice, now have few places to nest, and their numbers have been falling.
Mt. Diablo Audubon Society has had Eagle Scout candidates building and installing Barn Owl nest boxes for natural rodent control in parks and open space to deal with gopher problems. Scouts have made educational displays of skulls found in pellets inside barn owl boxes for places like Lindsay Wildlife Experience to show their visitors what these owls eat.
It is crucial that the Barn Owl boxes are built following appropriate designs, as there are lots of unfortunate stories of what is found when they are not constructed correctly.
Sometimes attracting Barn Owls requires patience. In 2013, Conservation Chair Nancy Wenninger had two nest boxes installed on her property as part of transforming her garden to California natives. Finally, in 2019, she was delighted to hear a noisy barn owl family occupying one of the boxes. The young successfully fledged, and Nancy is hoping they will return next year to take care of her gophers and voles. Thankfully none of the neighbors complained about the noise.
One way to acquire an owl box built by local Scouts would be to make a $100 donation to Native Bird Connections.