Refuge Notebook
Article
February 10, 2006
Kenai Peninsula Owls are in the market for a Good clean Home
By: Todd Eskelin
Last night with the moon poking through a somewhat hazy sky, I went for a walk to stretch my legs after a hard day riding my computer around the office. It was a perfectly still night, yet warmed by the moist southern air that recently flooded south-central Alaska. After grabbing my gloves from the truck I headed down the driveway. In the distance I heard a fast steady beeping tone, spawning from the mature spruce stand that dominates the area behind our property. The sound was not dissimilar from the annoying beep my truck makes when I leave the headlights on. But, this was undoubtedly the call of a Boreal Owl drifting across the lowlands.
 Though it seems like we are still well in the throes of winter, spring is actually right around the corner. Kenai Peninsula owl species can be heard calling any time of the year, but I often hear Great Horned and Boreal Owls starting up their courting duets toward the end of February. Who knows, maybe Punxatawney Phil is not in tune with global warming and Ollie the owl knows we are actually in for an early spring. Let’s hope! Whatever the case, owls on the Kenai often nest long before the snow has completely left the ground. Many will be sitting on eggs by mid-April and many will begin nesting in March. With a 32-day period from eggs to hatchlings there will be some ravenously hungry chicks in the nest towards the end of May or early June. The cycles of nature always amaze me. About the same time I start seeing the first batch of young red-backed voles emerging from their dens and wandering around in search of food, there will be many hungry owl mouths to feed.
The sound of that owl calling reminded me that if I had hopes of getting my owl boxes up in time to entice any residents this year, the time is now. Courting Boreal Owls will often call back and forth for days or even weeks at a time, but in the darkness they are also searching, testing, and locating the perfect nesting spot. Since both Boreal and Northern Saw-whet Owls are cavity nesters, they are relatively easy to coax into a man made nesting cavity. Bob Dittrick, an owl researcher in Anchorage, has over 100 owl boxes that he monitors and has noted Boreals nesting as early as Valentine’s Day.
Over the years, Dittrick has tracked the diets of Boreal and Saw-whets from the remains left at the boxes. These tiny predators prefer red-backed voles, but have taken everything from snowshoe hares to little brown bats. Imagine this 4.5- to 6-oz owl, silently swooping on prey that is 7 times its size. That would be like you or me hunting a young moose with our bare hands. If you would like the opportunity to follow the life histories of a Boreal or Saw-whet Owl, take a little time this weekend and build an owl box. Maybe you will be rewarded with the opportunity to see one of these stealthy hunters searching for voles in your back yard.
So, if you are up for building your own owl box, it is fairly cheap and simple. The materials cost about $15 and it is a fabulous opportunity to get the kids out in the garage working on a project with you. Basically, the box should be 7 to 9 inches square on the bottom and 15 to 20 inches high along the front face. The roof should be sloped down towards the front with an eve extending over the entrance hole. Then the three-inch entrance hole should be positioned 12 to 15 inches from the bottom. Remember to make the roof hinged, as it is important to clean out the old nest debris annually. This keeps the birds from being infested with parasites. Some birds have been known to reject old used nests, so this annual cleaning may keep your occupancy rates up.
Placement of the box is almost more important than the box itself. Birds are not going to use the box if it is easily seen from your house. Put it back in a place that has a mix of large spruce and aspen or birch. The birds will often prefer a nest box placed a minimum of 10 feet off the ground and higher if possible. It should be very well secured to a larger aspen or birch. Not only is this preferred by the owls, but it may help reduce the number of squirrels that try to nest there. The local birding group recently held an owl building party and made 11 beautiful nest boxes in a short afternoon. For more information on how they did it or upcoming bird-related activities, contact Ken Marlow (262-5218). For a more detailed description of owl box dimensions and proper placement refer to the following links:
http://www.mindspring.com/~owlman/birdingmagazine.pdf or http://www.50birds.com/MPb071614-212-412.htm
Good luck with your owl box building and please contact me with any successful occupancy. We would love to visit your site and maybe even band any nestlings that are produced.
Todd Eskelin is a Biological Technician that has worked at the Refuge since 2001. He specializes in bird studies and has worked throughout the state on various bird related projects. To contact Todd call the Kenai National Wildlife Refuge 262-7021.
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