Screech-Owl Nest Box

by  Eric Huish


 

Nest Box on Pole in Backyard  by Eric Huish  ©Eric Huish      
       

 

When you think of birdhouses you think of birds like Bluebirds, Titmice, House Wrens, Tree Swallows, and Purple Martins. But these are all birds that would never nest in my yard. I bet most of you live in a residential area as I do and I’m going to assume these species wouldn’t nest in your yard either.

So what would be the easiest bird to entice to a nest box in our yards? That’s right, House Sparrows. But you probably already have enough of those. So what’s the second easiest? You probably don’t want Starlings either. How about the third? Black-capped Chickadee maybe? Well, I’m not writing about Chickadees. I’m writing about the fourth easiest, and by far the coolest, species to attract to a nest box in a suburban setting along the Wasatch Front...Western Screech-Owls.

Almost every description of Screech-Owl habitat I’ve read mentions the use of suburban areas. (Kaufman and NG Field Guides for example). Robert A. Behrstock writes in The Sibley Guide to Bird Life & Behavior, "Habitat loss associated with human residential development has had an impact, usually a detrimental one, on many species. However, Eastern Screech-Owls inhabiting neighborhoods with mature trees may have higher survival rates than countryside populations, thanks to a lower diversity of predators, greater availability of water and of prey attracted to bird feeders and garbage cans, the suitability of lawns as hunting areas, and the warmer conditions associated with urban enclaves." One of my first sightings of Screech-Owls was when Ned showed me some from a parking lot next to the BYU Campus and this year Screech-Owls raised several young in a tree right next to the busiest sidewalk at UVSC.

I know what you’re thinking: "I’ve never seen a Screech-Owl in my yard!" Well that’s because they are very sneaky. I’ve got owls in my backyard and I have to make an effort to be outside at just the right time to see them. In fact they were nesting in my yard for a month before I even knew it.

Your neighborhood is likely good Screech-Owl habitat. Your bird food at night becomes mouse food and if your neighbors’ cats are like my neighbors’ cats, they fill up on birds all day - which leaves your mice predator-free. But Screech-Owl population growth in such habitat is limited to the availability of nesting cavities. People seldom let old rotten trees stand in their yard. They could fall and hurt someone. Well-built nest boxes seldom fall on people and Screech-Owls like them just as well as trees. ( www.cornell.edu: "Both species [Eastern and Western] use nest boxes, and field studies show that boxes are selected as often as natural cavities for nest sites.")

Screech-Owl boxes need an interior floor size of at least 8" x 8" and at most 10" x 10". The inside height should be from 15" to 18" and the hole needs to be a 3" diameter circle and should be centered 12" to 13" above the floor. You should also put some drain holes in the floor, cut some notches on the inside front wall to help the young owls climb out and place an inch or two of wood shavings in the bottom. I built my box out of 2x’s which is heavier wood than you’ll find in most instructions, but I think the thicker the better. I sandwiched a 2"x10" front and back wall between 2"x12" sides which made an interior floor size of 8 ½" x 9 ½" and I nailed the front wall on with two nails at the same height near the top of the wall and put one removable screw-bolt at the bottom so I can unscrew the bolt and swivel the front wall up to clean out the box. I buried a 16' Pole 3' in the ground in the quietest corner of the yard, put the box on top and a predator guard around the pole. (You may have raccoons in your yard and not know it. They are very sneaky also.) If you live in a neighborhood with open space and few trees, this same size box will be used by Kestrels. If you have a cabin up in the mountains and cut the entrance hole to 2 ½" the box could be used by Flammulated and Saw-whet Owls.

I need to warn you that Screech-Owls may not find your box right away and if they don’t, Starlings will use it. If this happens just open the front of the box every couple weeks, take out the eggs and feed them to your pet snake or put them on the tray feeder with the peanuts for the Jays and Magpies.

In any case, if you patiently put up with Starlings, it will eventually pay off when the owls move in because that’s when the fun starts. At dusk just as it’s getting dark but before it’s too dark to see you can go out and, watching quietly from a distance, see a previously mysterious, seldom seen creature out on the prowl hunting for mice over the bird feeders or snatching moths from the flower garden and taking them back to the nest. Once they find the box they’ll likely stay in your yard year round. It is now November and when the sun hits my nest box just right I will sometimes see a Screech-Owl sitting at the entrance sunning itself. They will add a nice touch of nature to your otherwise boring yard.


Follow-up Report
( An e-mail from Eric -- 3 May 2004 )

My Screech-Owls must have a large brood this year because for the last couple weeks they have been coming out to hunt extra early. As early as 8:35, while there is still plenty of light to see them well.

Last night I was alerted to an owl out hunting by the usual American Robin and Scrub-Jay alarm. The alarm is easily heard from inside the house and has been going off a lot lately. I went out to watch and got some very nice looks, then I sat a chair out across the yard from the nest box and watched. Last night was so calm and warm and the moon was so bright I sat there and watched the owls for over an hour while they made frequent trips to the box to feed the nestlings. The nestlings begging calls were loud enough for me to hear from across the yard.

If you enjoy bird watching I highly suggest you put a screech owl box up in your yard. (Unless you live within a block or two of my house). Screech owls used to be a two or three times a year bird for me but now I see them all the time. You can see screech owls with a tape player and a light but I think it is much more fun to see them in more natural circumstances like silently fluttering by in the moonlight.

A few months from now a young screech owl is going to come through your neighborhood looking for a place of his own. If there is no housing in the area he won't stay. If you think an owl in your yard sounds fun you should put up a box before fall. I think it is well worth the effort.

 

Nest Box Close-up  by Eric Huish  ©Eric Huish
   

Owl Catching Some Sun
  by Eric Huish  ©Eric Huish
 

Western Screech-Owl in Summer
  by Eric Huish  ©Eric Huish
 


    Additional Photos
   
(With a large brood in the box, there's lots of action in the yard).


Out Hunting - 17 April 2004
  by Eric Huish  ©Eric Huish
   

Owlet at Box Entrance - 12 May 2004
  by Eric Huish  ©Eric Huish
       

Adult Waiting in Nearby Aspen - 12 May 2004
  by Eric Huish  ©Eric Huish
       

Jays mobbing your owl box is a sign that there's an owl inside.
  by Eric Huish  ©Eric Huish