“Owl Boxing” – Building a Barred Owl Nest Box
Our greatest blessing at Solitude Mountain, Idaho is the very special 40 acre wilderness parcel we acquired in 2014. Yes, we’re building our home on this great site. That is exciting, but we don’t want our house to overshadow the reason we moved to the woods. Our primary focus is to assure that our residency does not impact the quality of living for local wildlife, and that we make nature the highlight of this property. In the greater scheme of things, this is most definitely not “our land.”
“Husbandry” is a term I have taken to heart over the many years of my education in biology and conservation. Although this term is often used to describe the practice of nurturing domestic animals, we believe it also should be used to make a natural environment more desirable to wild ones. It is not our right to inhabit wild places, but rather our privilege. As we embark on developing the wilderness 40, we hope that in many ways we can make the habitat for wildlife better than before we arrived. The first project we have chosen is to build owl nest boxes (homes) for Barred Owls.
Barred Owls are widely found throughout the continental United States and Canada. They are well adapted to living in a wide variety of climates and biomes. As with many owl species, their greatest challenge is finding adequate nesting habitat. With fast-paced urban and suburban development, owls are pushed to the periphery of their ideal home ranges. Here in the Rockies, this development is typically in prairies, river valleys and other low-lying areas where large cottonwoods and other deciduous trees often grow. Mature deciduous trees such as cottonwoods offer ideal nesting habitat for cavity nesters such as barred owls. When owls are pushed to peripheral habitats, they often end up on properties such as ours, dominated by coniferous pine, fir and larch. Our property has ample food, water and cover but little to no nesting habitat. Thus, the carrying capacity for owls is minimal. The best thing we can do to support a keystone species such as owls is to do our part to create that which is missing in their world. So we set off on our first “feel good” project of the spring….
For this project we did not want to reinvent the wheel, so we deserve no credit for designing our owl box. Many have conducted research on barred owl nesting areas to determine the proper design and specification of the ideal owl box. For reference, we used Michael Cantwell’s design found at owlpages.com. Please visit his Owl Box Page if you wish to follow the exact steps we followed. We will provide a basic overview as follows….
The good news is… building these boxes are easy, quick and affordable. This is an excellent project for people of all skill levels, including kids age 10 and above with parental supervision. The entire owl box can be created from four 2 foot by 4 foot panels of 3/4″ plywood sections or two 4×4 foot sections. We elected to use birch as it is stronger and more weather resistant than pine board. The birch plywood was only slightly more expensive than pine at our local Home Depot and requires little to no sanding. The first steps were to measure and stencil all owl box sections on the plywood slabs.
For ease and safety we elected to cut the entry hole to the box with a jigsaw prior to cutting the box sections apart with a portable Skil Saw. We also pre-drilled drain holes in the base floor section. It is imperative that you have a level, sturdy worksite for cutting. As you can see we used two saw horses to stabilize the plywood slabs prior to cutting. We had all sections sketched, cut and ready for assembly in just about 30 minutes! Since this project does not necessarily involve complete precision, it is fine to use rudimentary tools. Many people enjoy the challenge of building with hand tools, or choose to do so for safety’s sake when building with children. Eye and ear protection, as always, is a must.
Assembling the owl box sections is a bit more tedious. You will need two people in order to do this, as it can be a bit cumbersome for one person to hold two panels flush, glue and nail simultaneously. We assembled one section at a time as instructed and in the order outlined in the manual. Waterproof Elmer’s wood glue was applied to each side of the panels prior to assembly. This creates a strong, waterproof barrier to provide rotting and to assure excessive moisture does not enter the nesting area. Owls can be particular with the environment within their nesting area, so it’s imperative that the box is property sealed and dry. If each panel was not cut completely straight and larger gaps occur after assembly, some silicone exterior caulking could be necessary to fill in gaps.
One very cool (and important) feature of the owl box interior is the “owlet ladder.” Seeing as the main purpose of this box is secure nesting habitat for owls, the goal/hope is that our efforts will lead to a new generation of owlets. As the box is fairly deep, it will be essential to have a means for baby owls to easily climb to the entry hole when they are mature enough to leave the nest. Therefore, we created an owlet ladder. It’s as easy as simply using the previously cutout section of the entry-way, invert it and screw it to the interior of the owl box prior to assembly. The ladder sections are just parallel grooves cut by our Skil Saw with depth set at 1/8th inch. With sharp claws, the owlets can easily climb the ladder to take their first small step for Owl-kind…
Take the time to do a good job when assembling. Complete assembly took us approximately 30 minutes. In addition to the glue, each section was secured with 2″ stainless flat-head nails approximately one every 4″.
We let the wood glue and caulking dry overnight prior to finishing our owl box. Using a small 10″ strip of 1×2 board we had left over from a previous project we created a perch that we secured just below the entry way to the box. A few pieces of the 3/4″ plywood were used as shims to space the perch apart from the front wall. We chose to stain the box a “bark gray” color to match the color of the fir and pine trees on our property. It’s a goal of ours to our best to make everything we build blend naturally into the surrounding environment. After 4 hours of drying in the sun, we coated over the stain with a generous layer of Spar Urethane. We then secured two metal “T” brackets in the back center of the top and bottom of the owl box. These will be for easily securing the box to the tree. Finally, we added approximately 1/2 bag of medium wood chips to fill the interior of the owl box at a depth of 6-8″. This provides an ideal nesting base for the new residents of this classy estate.
It’s game time!
Taking it to the field! It is essential to find the best location on your property prior to hanging your owl box. If the box is located in a poor location, chances become slim that an owl will choose to move in. Owls like all animals in nature have criteria they consider when choosing where to hang their hat. Their most important requirements as discussed on owlpages.com are as follows:
- Try to select a location that is 30-200 feet from a water source.
- Try to keep the owl house 100+ feet away from a house or building.
- Try to keep the owl house away from roads. Barred Owls fair very poorly with cars. They tend to fly
very low and have a high incidence of car impacts.
- Try to place the owl house facing north, or in a location that is protected from the sun.
- Male Barred Owls are the ones who pick the nesting location. Males like to roost in a nearby tree. If
you have a conifer tree nearby, this will help attract them to using the owl house.
- The best time to hang a Barred Owl house is November. In November the bees are hibernating, and
Barred Owls will have 3 months to find the house.
- Try to pick a tree that is 1 foot or larger in diameter.
- The Barred Owl House should be in dense woods, but the entry hole should be fairly open for easy flying
to entry hole by the male barred owl.
Hanging your owl box in the tree you have selected is not particularly safe or easy. This should be done by an adult only plus a helper, and it should be done so with use of a very secure ladder in a location that the ladder can be propped on level ground. As the owl box will weigh over 20 pounds, do not attempt to carry the box with you on the ladder. We made the safe decision to hang a pulley system in which we could hoist the box to the desired location. While on the ladder, we attached a small pulley ($4 at home depot) with rope to the base of a sturdy branch about 15′ off the ground. We fed 3/8″ paracord through the pulley, enough for both ends of the cord to reach the ground. One end of the cord is tied off to the owl box, and the 2nd end will be our hauling end to hoist the box to the tree. When the box has been hoisted to the desired location, we tied the hauling end off to the base of an adjacent tree to hold the box firmly and safely. Now we can climb the ladder and secure the box in place. We used a portable drill with nut-driver and 3/8″ x 4″ galvanized lag screws to secure the box. 4″ screws will not be long enough to reach the heartwood of the tree and cause tree injury. We slid a 1/2″ washer followed by a 3″ compression spring onto the lag screw before securing the screw to the tree just enough to hold the box firm. As the tree grows, the spring will flex, extending the time before the box needs to be re-hung.
After the box is level and secure, the paracord and pulley can be removed. And voila! Our owl box is good to go and officially on the market! Our next step is to set up a trail camera eye-level with our new box to see if in fact we do have new neighbors this summer!