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By Nic.Korte

Annual owl prowls have long been a major activity of Grand Valley Audubon Society. What we have been calling the "Valley Owl Prowl" has existed for more than 30 years. Unfortunately, as with some of the birds we target on our many field trips, the owl prowls are in danger.

In designing this year's "Valley Prowl," I had located a Western Screech-owl (WESO) that seemed perfect. WESOs are common enough in our valley, but in April, when we do the "prowl," they are secretive, sitting on eggs, or hiding in the newly-green leaves. This particular owl was still sitting in the hole of a nest box. I liked the location because it was practically inaccessible unless one was let through the house or the locked gate by the landowner. We could also view the owl from a porch which would minimize any disturbance. The homeowner was happy, excited even, about having us. Then the spouse came home! "Knowing birders," I was told, "they'll come back. They'll try and look over the fence. They'll sneak in from behind the fence. Nothing doing!" That was it. I hadn't found another easily viewable WESO, and the field trip was the next day. No WESO this year.

Fortunately, I had suitable, and difficult-to-access locations for Great Horned Owl and the increasingly rare Barn Owl. What remained was the Burrowing Owl--also a rapidly-declining species. Once very common in our valley, Burrowing Owls have become more difficult to find with most of the migratory populations considered endangered, as in Canada and the US northern states. Indeed, Colorado may be the most northerly migratory population that has not been officially “listed” in some fashion. 

Burrowing Owls are tricky for our valley field trip because our early April date just coincides (or not) with their return from Mexico. Some years, we miss Burrowing Owls, because we are too early.

I had found a pair, just a few days before the "prowl" but it wasn't suitable to some of my co-workers. The owls were on public land in an easily accessible area. "You will be sacrificing them," said one of my friends. Fortunately, other owls were found on private land, behind a barbed wire fence where viewing was easy, albeit distant, from a road.

We had a successful field trip, although sans WESOs. Quite a few photographers were present, and some expressed disappointment at the distance at which we viewed the Burrowing Owls.

I should say here that I give all participants a handout describing how sensitive owls are during nesting season. Remember that female owls stay on the nest from the time the first egg is laid until the young no longer need brooding.  This means the female stays on the nest for weeks!  A few Great Horned Owls tolerate some disturbance, but most owls do not. We had already stopped showing Long-eared Owls at our owl prowls because of evidence of too much encroachment following our revealing of a nest location. The nests were abandoned or predated. If an owl is disturbed from its nest, it may abandon it. Plus, a daytime flight reveals the location to ravens and other predators.
(Long-eared Owls are no longer part of our owl prowls because they are so vulnerable to predation. and abandonment.)

After this year’s "owl prowl," I was told that photographers who learned of the Burrowing Owls from us either returned or informed others. They entered the private property to obtain better photos. My informant, also a photographer, was incensed. "Now the owls are gone!" I was told.

After hearing this, I spent an hour out there myself, viewing from the road with my scope. I found no owls.

Remember the "too accessible" location that we didn't reveal? Viewing with my scope at about 300 yards I could see both an adult and a juvenile on the mound. This evidence is circumstantial, but for us, it is probably case closed, and we won't show Burrowing Owls in the future.

(Burrowing Owls are declining over much of their range because of development, shooting, and off-road vehicles.)

Grand Valley Audubon Society is committed to educating the public, and that includes birders and photographers. Both groups contain individuals who exhibit the best and worst of sensitivity to wildlife. We will probably continue owl prowls but I don't think there will be Burrowing Owls next year.


This post provided by Nic Korte, Grand Valley Audubon Society. Send questions/comments to To learn more and to participate in the activities of Grand Valley Audubon, please see, send an email to and “like” us on Facebook!]