Sunny Slope Orchard

Sunny Slope Orchard
In the coast range foothills overlooking the Sacramento Valley

Tuesday, January 15, 2013

Our Barn Owl Rodent Patrol

A family of barn owls comes out of their hollow tree
In the early days gophers were a constant problem, devouring our garden vegetables and gnawing through roots of young trees. Then one Spring we noticed a family of barn owls nesting in an old oak tree across the road. Watching with binoculars at night, we could see the parents flying in and out of the nest, a hollow cavity in an old branch, delivering rodents to their young.

Upon reading that a nesting pair and their young can eat more than 1000 rodents per year, I began making and installing barn owl nest boxes on and around our property. I felt that additional nesting sites would help establish a local colony. Given the declining number of barns and large old trees with hollow nesting cavities, it turns out that nest boxes are a sure way to encourage owls to live and breed in an area.
Four young barn owls in their tree trunk nest

The same owls just two weeks later
Now years later, our gopher problems have gone from out-of-control to insignificant. Many years we've had a bumper crop of new owls from multiple nest boxes, often with five to seven owlets per nest. 
I would strongly encourage anyone with rodent problems, or anyone just wanting to encourage owl populations, to  consider putting up a nesting box or two. Just Google "barn owl nest boxes" and you'll get a wealth of information. 

Young owls in a plywood nesting box

Above are five young barn owls inside one of my nest boxes. Note the age difference - the mother lays an egg every day or two, but begins sitting after the first egg is layed, resulting in staggered hatching and quite an age difference among the chicks.

Seven young owls crowded in their box
Above is a big family of seven owlets. We noticed the parents roosted elsewhere, appearing only after dark to hunt and drop off food for the young.

To take these shots, I waited until dark when the adults went out hunting, then climbed the tree and used a digital camera with flash.

Above is one of the adults, relegated to roosting in a tree since the nest box was overcrowded with young.

This adult peeks out of his box. I locate the boxes to give the owls
as much privacy and safety as possible, but it is a great joy to catch
a glimpse of them using binoculars or a telephoto lens.

A young owl takes his first tentative hop,
from the nest opening to a nearby branch
It is a real pleasure to walk outside at dusk and catch a glimpse of an owl, cruising silently over the orchard, on patrol for rodents. Who says you can't find good help anymore?