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| Introduction: Barn Owls 101This morning we went to Google Earth and studied the farm country just east of Harrisonburg, Virginia. The area we were checking is nestled in the Shenandoah Valley. The satellite views told us that the land use looks very good for barn owl habitat.
As we drive around the actual farm country that we'd seen from the satellite photos, we further refine our search for old silos that would more than likely be retired from active farm use. Then we spot the old brown barn and silo.
The Old Brown Barn and Silo
 Our spirits are high as before you can study barn owls first you have to find them and, in order to find them, you first have to find a prime silo for them to nest in. And, if the bottom of this silo has been sealed up (the bottom of the silo has the chute doors closed) this brown silo will have barn owls.
Jill takes her position in front of the silo while Lance approaches the silo from the back where the silo chute is located and the silo can be climbed from inside the chute. Jill's job is to watch for any owls that might fly out as Lance climbs into the silo. One of the things Jill is watching for is the color of the breast of any owl as it flies out of the silo. A white breasted owl in our study area tells us it is a male. A light reddish brown breast indicates a female owl. When we flush a female owl during this time of year we consider it a good sign that she is nesting there.
With Jill in place Lance starts at the bottom of the silo chute and begins climbing up. He uses the metal steps that are attached to doors that seals the silo and keeps silage inside. As he ascends he taps on each wooden door to determine if there is silage piled behind it. Fourteen feet up into the silo chute the door taps with a hollow noise indicating no silage behind it. As Lance pries open the door, Jill yells out from out front of the silo, "A barn owl just flew out!"  Lance hollers, "What sex?" - to which Jill replies, "A female". It is looking likely that we'll find young owls inside this silo. Lance takes the door off and enters the silo which is partly filled with old silage that is brittle, dusty and riddled with small caves. Jill quickly climbs the silo and enters too so she can assist Lance in checking all the caves for evidence of barn owls breeding inside. We already know barn owls use this silo for roosting during the daytime since one just flew out and we've seen many pellets, the regurgitated bundles of fur and bones that are not digested by owls.
 Eventually the young owls hiding in a silage cave spot us poking around and they foolishly begin hissing loudly, giving away their position. Eureka! We have seen several barn owls that appear to be 3-5 weeks old. They slide back into the depths of their cave as we approach.
Now we need to extract them from their hiding hole to give each a uniquely numbered bird band from USGS Bird
Banding Laboratory. 
With her super long arms Jill is just barely able to reach to the far edge of the cave
with a gloved hand. The owls instinctively lock onto the invading glove with their feet and
are easily brought up by Jill for banding. The six young owls try to bite and grab us with their surprisingly powerful feet during the brief banding procedure. They will retain these aluminum leg bands for the
remainder of their lives. If they are ever recaptured, spotted with
a spotting scope or found dead or injured, this band number will enable
us (via the
Bird Banding Laboratory) to trace exactly where and when each bird was recaptured. This feedback gives us valuable information on the
life spans, causes of mortality, dispersion of young owls and other statistics about our Virginia barn owls. Everyone who finds a banded bird should get the number and report it to the
Bird Banding Laboratory by calling the toll-free number printed on the band or online: http://www.reportband.gov/******************************************************************************************************************************** Probable History of Barn Owls in Virginia
by Lance & Jill Morrow
In Virginia, as in most of the world, barn owls are birds of open ground. They hunt their prey by floating 5-15 feet above the ground as they course open fields and marshes. When they locate a prey item, small rodent, by sound they will drop down and grab it, bite it in the head then swallow it whole.
Prior to the Caucasian race coming to North America it has been said that a squirrel could climb a tree at the Atlantic coast and could travel west transferring from tree to tree without having to come down all the way to the Mississippi River. During this time we can only speculate that barn owls occupying Virginia were restricted to the open coastal marshes of the Chesapeake Bay and the Atlantic coast. These owls were nesting in hollows of large trees, holes in banks along waterways and coastal bluffs.
White settlers came to Virginia in the early 1600s and started clearing land for farms. As settlers moved westward across the Piedmont and into the Shenandoah Valley barn owls followed them. The barn owls still used their traditional nest site locations but started to add man-made structures such as barns, houses, chimneys and abandoned wells as nesting sites.
In the late 1800s American farmers began to use tower silos to store livestock fodder over the winter. Virginia's barn owls readily took to these new man-made sites and used them as a safe roosting site, and when applicable, a good nesting location. In our study area in the north part of the Shenandoah Valley of Virginia, we chose silo inspection as the best method of censusing barn owl populations. In 2009 we determined that barn owls were utilizing 48 silos in our 144 square mile study area which works out to a density of approximately one pair of barn owls per 3 square miles, not taking into account other situations that barn owls may be nesting in (barns without silos, for example).
In Virginia farmers are using different silage storage methods and hence retiring more and more silos which potentially makes them available to barn owls for roosting and possibly nesting. The downside is that some retired silos are being torn down (or are falling down on their own) as they are no longer structurally sound and are of no use to the farmers; while in other areas farms with their silos are being lost to urban sprawl.
Above is one of the few remaining silos in Virginia built with wooden planks. Most are probably over a century old and haven't been used for about 80 years. Please note the square roof on top of the round silo. The square roof provides four corners that offers the barn owls a safe, high place to lay eggs and raise their young. Generally the barn owls will regurgitate many pellets full of the hair and bones of the field mouse or meadow vole (Microtus pennsylvanicus). Whether intentional or not, while owls are walking over them, the pellets become shredded and make a good base upon which the barn owl will lay her clutch of eggs and incubate them.
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