Barred Owl Nest Box

lyle11

501 Club
I haven’t seen a barred owl in 50 years at my farm in Wisconsin but I hear them most nights when I’m there. When I was a kid, I was into taxidermy for a couple of years, and I’ll admit I shot a barred owl and mounted him. Just about the easiest bird in the world to mount with feathers that make the body look twice it’s size so it was easy to hide my amateur mistakes.

I only have about 35 acres of woods on my property but the adjacent property has about 200 acres of woods. Part of it was logged and thinned last fall so there is a chance their nesting tree was cut down or area disturbed enough to look for a new site. Ideally, I should’ve got my house up last fall, but I just built it over the winter for a project. Just the kind of project I like where I’m not left with something I don’t need taking up space.

There are different ideas about using treated plywood to make the box. I decided it to go with untreated plywood. I used some of that self adhesive roofing tape for the top and back to hopefully shed water and extend its life. Then I applied about 5 coats of linseed oil to the exterior wood on a nice hot day and let it soak in.

To accommodate for tree growth, I used flat T shaped steel brackets (Simpson Strong Tie) and hanger bolts with a coil spring and lock nut to allow for expansion. There are also conflicting recommendations which direction to point the box. Since this up north, I faced it Southeast. Down south they recommend facing them North. I figure in Wisconsin they will like a little sun coming through the trees in the late winter and early spring.

I found an old pulley and rope in my shed. My sister pulled it up and I hooked it over the hanger bolt. Not sure if I’ll ever get owls. Barred owls are very shy staying in the woods so I made sure it’s well off any area I go to. I read conflicting information whether the owls will evict squirrels if they like the box.

I was reading something a few years ago about a Great Horned Owl, that if the young owl falls to the ground, they actually have some kind of appendage on their wing joints to climb their way back up the tree. Not sure if a Barred Owl has that. This house is about 17 feet off the ground. I read in advance that it should be between 15 to 30 feet. If it’s been any higher than 20 feet, I wouldn’t have made it since that’s about as high as I ever wanna climb. I would’ve thought they would want to be higher in the tree, but I imagine with their young being prone to fall they don’t wanna be too high up.

Obviously, there’s a good chance I never get owls in the box but it’s worth a try. I think it said that boxes should be at least a quarter-mile apart. I’m not interested in making any more nest boxes but I imagine the owls are very territorial. I may add a perch just below the hole. I see the occupied Barred Owl box near Indianapolis on the Cornell Labs bird cam site has a piece of branch for a perch.

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I have had a barred owl box a friend made for me from cedar for about 3 years! Every fall I tell myself & my 2 sisters that it was time to install it, but we never do! This year was close...we had some trees removed out at the farm, and the guys said they would mount it with their cherry picker. But then the equipment broke down...now I'll wait till next fall and I WILL finally mount it!

One of the big problems was figuring out how to get it up there, so I like your idea of a pulley system. Do you have a picture of the actual attachment points? Not sure I understand your brackets, hanger bolts & springs.

Yours looks great! Come to NC & mount mine!!
 
One of the big problems was figuring out how to get it up there, so I like your idea of a pulley system. Do you have a picture of the actual attachment points? Not sure I understand your brackets, hanger bolts & springs.


I got all this stuff off the Internet, so I want to give credit where credit is due although I don’t know what the website is. The picture should help explain what I did. I did not take close-up pictures of my parts.

My understanding is that if a house this large is just screwed to the tree or nailed to the tree. The fasteners will pull through as the tree grows, and then the house will fall to the ground. I’ve seen a set up with some type of rubber bushing or annual backing off of the fastener, but this seemed like the best way to go.

You need:

Qty 2 Simpson 6”X6” T- Strap or similar. (I think the part number is Simpson 66T) Home Depot and Menards have them. Roughly 6” wide and 6” tall. Flat steel shaped like a T. (See on photo below).
Bolts, lock washers and nuts. You drill holes and bolt through the house and securely fasten at two points with the third opening protruding above the roof and below the bottom. It needs to protrude enough for the hanger bolt with a nut.

Qty 2 - 3/8”X 6” Hanger Bolts. These are hard to find. I couldn’t find it at Ace, Menards, Home Depot. I bought mine on EBay. If anybody is not familiar with a hanger bolt, it’s a long straight bolt with a lag screw on one end to screw into wood and a regular hex bolt on the other end. The holes in the T straps are about 1/2 inch. I use two 3/8”X6” inch hanger bolts. 6 inches long.
So 3 inches went into the tree, and 3 inches protruded for the spring and lock nut.

Then I just drilled a hole in the tree at the desired height for the top bracket. Put on 2 nuts and threaded my hanger bolt into the tree. Then a pounded a nail, roughly a foot above the hanger bolt. Just a decent size nail like 10D pounded halfway into the tree and angled upward.

I found my pulley assembly just laying around, I think you could find a fairly light duty pulley type of assembly at Home Depot. Where you have a way to hang it on the top and then it would accommodate may be a 3/8” diameter rope over the top of the pulley. My pulley must’ve been about 6 inches in diameter.

I just hung my pulley assembly over the nail. My box was mounted at about 17 feet so I probably needed 40 feet of rope. Enough to loop around the pulley to the ground. And then enough to tie around the house. In my case I have an overhang on the front and sides of the house roof, so I just looped the rope under the roof overhang on 3 sides. It wasn’t going to drop with the rope tightened up and my 64 year old sister easily pulled it up into place. I had my other hardware with me and I just maneuvered the house so that the top strong tie went over the hanger bolt.(don’t forget to take at least a nut with you because of the irregularities in the tree trunk it probably won’t hang on the hanger without being secured).

I had four 3/8 “ flat washers. I took my hanger bolts to Menards and I found little coil springs for a dollar or two in their hardware area that you put over the hanger bolt on the outside of the T strap. Then I had a 3/8 inch nylon insert lock nut. Just for weather resistant I use stainless steel in case I ever need to remove it or back it off. I put one 3/8” flat washer over the hanger bolt first. (This is probably not needed but with a half inch hole in a 3/8 inch hanger bolt, I didn’t want any chance that the coil spring would get partially into the larger 1/2” hole and rest up or grow into the tree limiting it’s purpose). Then the coil spring over the hanger bolt followed by another flat washer, then the lock nut with the nylon insert. The box is not supposed to be super tight to the tree so you just tighten it enough so that your nut nylon insert is fully on the the protruding bolt and you want there to be spring tension between the T strap and the nut.

This allows the tree to grow, and of course the spring will compress as it grows. Not sure how many years it would take to expand, but I probably had about 1” for the tree to expand.

Then I had my sister check from the ground that the house wasn’t caddy wampus and I drilled a hole into the tree through the T strap installed the bottom hanger bolt, washers, coil spring, and lock nut.

I can’t tell you exactly what spring I bought. It’s a coil spring with a 3/8” ID roughly 1.5” long to provide tension against the bracket, but still allowed for expansion. It is possible as the tree grows, after a few years you could replace it with a shorter coil spring.

If you could get 8 inch hanger bolts, that would give you some extra room for tree expansion but they’re hard to find. Maybe something like Fastenal will have them. I didn’t look very hard.

Those two plywood strips on the back of the house are just to help of keep it centered on the tree. The house will not be tight to the tree. It’s not gonna move much in the wind, but if you wanted to, you could move it with your hand with some effort and that’s the way it’s supposed to be.

Just to be clear, the T straps are tight against the tree. Then the coil spring goes over the hanger bolt after the T strap is tight against the tree and is secured by the nut. The T strap and back of the house then moves out as the tree grows up to the extent of how much spring you have.

One other thing. Either before you put it up, or after while your ladder is still in place, you’re supposed to put some type of bark in the bottom of the house. I could only find pine bark and it didn’t specify anything specific. So if you put it up in the fall, you may want to buy some bark earlier in the year while they still have it at the garden center. I’ve heard conflicting views about the depth of the bark. One said 5 to 6 inches which I put in mine but it seems like too much. I read that barred owls are supposed to like a deep house and 5 inches of bark seems to be making a deep house into a shallow house. Thinking I’ll probably pull some out and leave about 3 inches in there.





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