Thursday, September 27, 2012

The [un]Common Barn Owl

Next up in our owl series is the Common Barn Owl!  Along with the Great Horned Owl, Common Barn Owls are the most commonly sighted owl in the region.  When I go out to programs and exhibits with the Humans, I often overhear stories along the lines of, "I saw this HUGE owl the other day in my barn - what was it?"  The answer is Common Barn Owl.  However, they're not as big as they seem.

c Jerry Liguari
Remember how I said Great Horned Owls weigh about 1.5-5.5 pounds?  Well, the Common Barn Owl is the next largest owl commonly found in Colorado, and it weighs a mere 0.5-1.5 pounds.   Yep, all that wingspan and majesty from a bird that weighs the same as a can of beans.  But when it's flying silently toward your face when you enter an abandoned warehouse or a little-used barn, you probably don't care what it weighs, you just don't want it near your eyeballs.  Barn Owls, however, are not aggressive birds, and they're merely trying to fly out of the barn to get away from you.
As the name implies, Common Barn Owls do spend a lot of time in barns.  But before there were barns, where did they hang out?  Barn Owls are cavity nesters, meaning that instead of building their nests in the sprawling and exposed branches of an oak or pine, they build their nests in tree cavities and hollows, as well as rock nooks and small caves.  However, since barns and other Human-made features are so warm, cozy and protected, Barn Owls often opt to nest in barns, silos, warehouses, and church steeples.  Barn Owls are also big fans of Human-made nesting boxes.  Humans can install these nest boxes on their own properties and see if a pair of Barn Owls comes along to take up residence.  Instructions for building your own box are easily found with an internet search.  Humans often install Barn Owl boxes to lure Barn Owls to their property as a means of rodent/pest control, as shown in this PBS video.

One reason Barn Owls are so good at controlling rodent populations is that they're insatiable eaters.  Catching and eating upwards of six vole-sized critters each night, they can really keep tight reins on the local population.  Also, it's incredible how many pocket gophers they can fit into one stomach!  Like most owls (including me), they generally swallow their food whole instead of ripping and tearing it like most other raptors do.  And Barn Owls don't even blink when it comes to swallowing animals that seem impossibly large.  Skip ahead to minute 3:30 in the video below to see what I mean.

The eating pace doesn't slow down at all when there are chicks in the nest, either.  Barn Owls lay between four and seven eggs, so that's a lot of mouths to feed when they all hatch.  And do they eat smaller, more appropriately sized food?  No way.  They eat just like mom and dad.  It's unreal.
Baby Barn Owls with a feather-duster "mom" at the RMRP

Baby Barn Owls are a little goofy looking.  Many Humans think they're adorable, while others think they look like alien pterodactyls. They certainly don't look much like their adult versions until they're many weeks along.  Adult Barn Owls, on the other wing, are simply stunning birds.  They're in the non-tufted class of owls, meaning they don't have ear tufts like I do.  They still have extremely prominent facial discs, however, which is largely responsible for their success as hunters.  Females of the species have slightly duskier coloration, with more brown on their faces and chests, while males are more of the snowy-white variety.  This often leads to people thinking Barn Owls and Snowy Owls are the same thing, but as you can see in this picture, they're very dissimilar.  For the record, Harry Potter had a Snowy Owl, not a Barn Owl.
Snowy Owl on the left, Common Barn Owl on the right
The Common Barn Owl, while obviously not common in appearance or behavior, is called "common" because of its wide range.  Barn Owls are found on every continent except Antarctica, and within each continent they inhabit every imaginable ecosystem.  Because of their extensive range, Barn Owls have numerous variations and subspecies, between twenty and thirty depending on who you ask.  Tyto alba is the Latin name for Common Barn Owls, and the variation in North America is Tyto alba pratincola.  Something kind of cool about their Latin name is that the word "tyto" is a Greek onomatopoeia meaning "owl"; "tyto" mimics the classic owl sound, like the English word "hoot".

Educational female Barn Owl foster mom guarding her charge
Barn Owls used to face a lot of intentional persecution as a species.  One likely reason for this is the owl's ghostly appearance:  with the white plumage, silent flight, and a knack for flying out of barns at Humans, they earned a reputation of evil associated with ghosts and death.  This is reflected in their other common names, which include Demon Owl, Ghost Owl and Death Owl.  Fortunately, as education about Barn Owls spreads, they're facing less and less intentional persecution.  However, like all raptors, they still face threats from the usual suspects: power lines, poisoning, car strikes, and more.  Habitat loss has led to the Barn Owl being listed as an endangered species in seven Midwestern states.

Educational Ambassador for the RMRP, male Barn Owl
At the Rocky Mountain Raptor Program, injured Barn Owls are admitted with all the above injuries and more.  Another common way for Barn Owls to come to the RMRP is via orphaning.  While their nest sites are often excellent cavities, they're not always stable or well-located homes.  Nests in hay bales, under trucks, in rafters, and in the walls of buildings are accidentally knocked down each spring, leading to entire nests' worth of baby owls coming to the RMRP to be raised by our resident foster parents.

So, there you have it, the uncommon Barn Owl.  Stay tuned next week for a profile on the Mexican Spotted Owl.   As always, you can email me with questions or comments at, follow me on Twitter @RaptorProgram, check us out on Facebook (Rocky Mountain Raptor Program), and find out more information and stories on our main website.  If you would like to subscribe to this blog, use the box in the toolbar to the right.

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1 comment:

  1. Thanks so much for all of this info. I love barn owls and just adopted one that is being cared for at our local zoo. I love learning as much as I can about them.