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19 March 2013

What's in a Name?

Before I go further with this blog, I have to clear up a very common misunderstanding. That owl you heard tonight in the nearby forest, or saw in the neighborhood, or had nesting in the back yard, was NOT a Barn Owl. I'd bet good money on it.

That's because, in the North Carolina Piedmont, approximately 9 out of 10 Barn Owl observations are cases of mistaken identity. OK, I made that number up. It's probably 95 out of 100. My friend Nate Swick, a reviewer for the citizen science website e-bird, sometimes gets Barn Owl "sightings" posted for our area. Invariably, these observations turn out to be made by inexperienced birders, or by individuals without corroborating evidence. The fact is, real Barn Owl sightings in the Triangle are exceedingly rare. Neither Nate nor I have EVER seen a Barn Owl in our home counties.

The funny thing is, the Barn Owl is so very distinctive, it couldn't possibly be mistaken for any other bird, (except perhaps for the Snowy Owl, a far northern species). They are white owls!!! Here's a photo of the European subspecies, Tyto alba alba, which is virtually identical to its American cousin. (Borrowed from Wikipedia, where the photo is in the public domain).


How could this bird be confused with anything else?? The answer most likely lies in the common English name, and an alarming accident in alliteration. The moniker "Barn Owl" sounds a heck of a lot like "Barred Owl." Here's what the Barred Owl looks like (also borrowed from Wikipedia):


This particular Barred Owl is much paler than the birds we have around here, and yet has vastly different coloration and patterning than the Barn Owl. The Barred Owl, too, is a bird of forests and swamps, whereas the Barn Owl is a bird of open prairies and farmlands. When discerning the two names in your head, remember that Barred Owls have bars or barring on them (those brown streaks), whereas Barn Owls do not. Also, you will rarely see Barred Owls hanging out in old barns.

There are other causes for confusion as well. The Barn Owl has a call that sounds like a terrifying screech. The Barred Owl has a call that is most certainly not a screech, but rather a more stereotypical hoot. Trained ears could never mistake those two calls. But there's a third owl in our area, the Eastern Screech-owl, that looks like this (once again, from Wikipedia):



There are actually two morphs of this Screech-owl: a reddish one, and a grey one. They are tiny owls, much smaller than the Barn Owl. But because Barn Owls screech, and the Eastern Screech-owl has the word "screech" in its name, there is often confusion. To make matters worse, the Eastern Screech-Owl rarely screeches at all. It typically makes a sound similar to a neighing horse, or another sound that is more of a descending trill. Listen for the Eastern Screech-owl in woodland areas, where it may venture out into the open at dusk.

So the Screech-owl doesn't often screech (only when agitated, actually). The Barred Owl has barring, and doesn't live in barns. Is there another owl that could be confused for the Barn Owl? Well, not really. However, the last of the four historic owls in our area can eat Barn Owls. Yeah, that's right, I said EAT. Behold the apex avian predator of the night, the Great Horned Owl (borrowed this time from National Geographic):



The Great Horned Owl is a massive bird, and a stealthy hunter, eating everything from rabbits to house cats to other owls. Biologists believe that increases in Great Horned Owl populations, which coincide with regeneration of forests in the Eastern US, may be contributing to decreases in Barn Owl numbers. If Barn Owls find themselves too close to a forest edge, they risk ambush from these large nocturnal hunters. The call of the Great Horned Owl is a subdued hoot, as if to say "I'm the biggest predator around. . .I don't need to announce my presence to anyone."

Some biologists believe Barn Owls are now seeking larger fields in which to hunt, so as to avoid being killed by the forest dwelling Great Horned. In eastern North Carolina, Barn Owls are now found in very large agricultural fields, with few trees in sight. In the Triangle area, we place our nest boxes in large open areas, with some distance from forest edges, especially where Barn Owls might be at risk.

That brings us back to our identification issue. Unless you have very large agricultural fields in your back yard (25 acres at minimum, but more likely 50 to 100 or more), you are likely not seeing or hearing Barn Owls. Learn to identify the three more common owls described, both by sight and by sound.

If you happen to be near one of our nest boxes at dawn or dusk, and you see a white owl working the field nearby, take good field notes. Get a photo if you can. Listen for the distinctive screech call of the Barn Owl, and make sure the screech is not coming from another critter (like a mammal). Then contact us at newhopeaudubon.org as soon as possible. We may be skeptical at first. Then, we might just be ecstatic.



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