Next time you drink a glass of California Chardonnay say a silent thank you to the Barn owls. Farmers in California are starting to use Barn Owls to control the rampant gopher population. Farmers use owls to kill gophers.
Barn owls are gopher eating machines:
In warm weather they'll eat two rodents per night and in cold weather that increases to three or four per night. Once we have babies in the nest that increases to one per night when the chicks are just hatched and up to six per night when the young are about ready to fledge!
Barn owls are ideal for land managment as human interaction does not seem to bother them. This is not withstanding their highly developed sense of hearing - they can actually hear gophers chewing on roots under the ground. Additionally, Barn owls aren't territorial and unlike other raptors they don't spend the bulk of their time chasing competitors away.
I would encourage anyone who has heard a Barn owl in their area or who has suitable habitat to put up a Barn owl box.
Here are a couple of sites that may be useful:
Nesting box - Barn owl box company
Biology - http://owling.com/Barn_nh.htm
Box placement and maintenance - http://www.wildlife-center.org/where%20and%20how%20to%20hang%20a%20nesting%20box.htm