GARDENING : OWLS CAN SOLVE GOPHER PROBLEM.

Byline: Joshua Siskin

There are hills and canyons in and around Los Angeles where gophers are such an enormous problem that gardening is virtually impossible. In parts of Santa Clarita and the Antelope Valley, the only way to plant is to sink a fine mesh fence to a 2-foot depth around your garden.

Trapping definitely works, but it is accompanied by the never-pleasant task of extracting the dead animal from the trap's skewers that pierce it on both sides. Oats laced with strychnine are the most popular poison bait, except that lots of people don't like handling noxious chemicals, and you can never be sure if the gopher got away.

Household pets, especially cats, have been known to afford some measure of gopher control, and there is anecdotal evidence that poisonous bulbs, such as daffodils, will not be eaten by gophers, suggesting that a garden surrounded by such bulbs will be gopher-free. Ultimately, neither pets nor poisonous plants are reliable deterrents to gophers.

As in so many other areas of life, the solution to our gopher problem may, in the end, come from above, in this case in the form of a bird found throughout the world, a bird that consumes not only gophers but moles, voles, mice and rats as well. This bird is none other than the common barn owl, a bird no bigger than a crow, with an unmistakable heart-shaped, chalky white, ``Phantom of the Opera'' mask.

The fact that barn owls eat gophers is hardly news. In fact, biologists have long been privy to the knowledge that March and April are the peak breeding months of both owls and gophers. What this means is that there will be plenty of prey for the owls just at the moment when they are hungriest and also have fledglings to feed.

This understanding has led to the reasonable assumption that if you could bring a pair of breeding barn owls into a gopher-infested area, the owls happily would take up residence and rid you of your gopher problem. But this assumption is wrong.

The breakthrough in owl-gopher research was reached when it was discovered that although barn owls are found throughout the world (excepting the higher latitudes), they only will come to an area by their own choosing. When you forcibly place them in a particular spot, they fly away. However, if you can build a proper nesting house for them, they will appear out of the clear blue sky and become your tenants.

To build an owl house, sink a 4-by-4-inch pole 4 feet into the ground and build a nesting box to be attached at the top of the pole, which should extend to a height of 12 feet above ground level. The nesting box should be 16 to 24 inches on each side, with landing dowels, an entry hole 6 inches in diameter in front, several -5/8-inch drainage holes at the bottom, together with a clean-out panel, and four -3/4-inch air holes on the side. If placed in the sun, as opposed to under a tree, a slanted roof should be provided on the top of the box, extending several inches over the front and back to give the owls shade. Care should be taken not to place the nesting box in an area of intense vehicle or foot traffic, since owls will not visit such noisy sites. Detailed instructions for building an owl nesting box may be found at www.rain.org (click on ``search'' and type in ``barn owl'') on the Web, or call [phone] to order a brochure on the subject.