Tawny Owl, Strix aluco, nestbox, nest box, design, construction

Nest boxes others are using

Chicks in the nestbox at Brow Farm 15 May 2003

HAPPILY IT SEEMS that it's mainly here in Britain that nestboxes for Tawny Owls are so dominated by a couple of unfortunate but officially sanctioned designs. Elsewhere they do it differently. Not so different, perhaps, but different enough to make all the difference. It's all in the dimensions. The floor area is larger relative to the size of the owl, and there isn't the excessive height that makes entry and exit like an assault course. With these simple changes you get a roomy box that's not like something from a battery farm and is easy for parents and young to enter and exit.

This page takes a look at examples of what others are making or buying to put up for their local owls. In the US the equivalent of the Tawny Owl, and a close cousin, is the Barred Owl, Strix varia. Two of the boxes on this page are for this owl, which has similar nesting requirements. At 16-20 in long, though, it's rather larger than the Tawny, which accounts for some of the greater size of the boxes provided for them. The American-style letterbox with its owl-friendly dimensions and lower entrance is an altogether different beast from its english counterpart.

Some examples from the UK show that there are some owl-friendly designs around. Here I include my own as possibly helpful.

If you have, or know of, a nestbox that could be included here, please email me with details (at raham [atsymbol] btinternet.com). Obviously boxes for Tawny Owls are what I'm after, but details of boxes for similar owls with interesting and/or relevant design features would be welcome.

BOXES FOR TAWNIES

Private owner, Ede, Gelderland,The Netherlands

One of a dozen or so tawny owl boxes made by this owner. This is what I call the "Dutch letterbox" design.

Dimensions: 35 cm x 35 cm (sides); height at back 55 cm, at front 45 cm. Entrance 15 cm diameter.

Materials & constrn: timber and nails; Attachment: nailed/screwed back batten.

Photo © Arnold van den Burg

Close to being my perfect boxjust needs a ledge and floor drainage. Design is from Mooij, J.H. (1983) De Bosuil [The Tawny Owl]. Kosmos, Utrecht (ISBN 90 215 1139 8), page 97. Size and proportions are ideal, avoiding the faults of being too deep and narrow. It's thus more like the American letterbox design which I'm advocating on these pages than the cramped British designs.

Find construction plans on the Making Your Own page. For my own, see below.

Private owner, West Dorset, England

Home-made tawny owl box made to modified Dutch letterbox design.

Dimensions: 45 cm x 30 cm (width by depth front to back); height at back 66 cm, at front approx 60 cm. Upper part of box is about 41 cm front to back.

Materials & constrn: Shiplap panel screwed to batten frame. Floor and side panels removable for access. Attachment: single batten fixed in place with exterior grade Timberfix wood screws.

This is a really nice nestbox, details of which are just coming in from the owner (Sept 2009). It's on a tree between the garden and an "ancient track [which] has sunken with use and is overgrown with neglect, bushes and hedges becoming substantial trees and undergrowth." There are tawnies in the area, and for some time the owner had a chimney-style box out for them, but it wasn't used. He knew about this website and decided to run up a Dutch letterbox to see if the owls are tempted. We shall see!

The special feature of this box is the interesting semi-protected ledge. The box faces east, away from the prevailing westerlies, and with an approach that's clear of branches.

The owner/maker has some handy tips on lifting and attaching a bulky (though he says light) box like this, and I've included them in the section on Tree Attachment Methods: Ratchet straps for lifting and Driving screws home

NEW: There's now a page on this box with photos and description.

Private owner

Home-made tawny owl box made to modified Dutch letterbox design.

Dimensions: 400 x 360 x 570 mm (OD), 360 x 320 x 530 (ID). That gives a roomy internal diagonal of 19 inches.

Materials & constrn: Recycled bedroom floorboards.

Comments: Posted on Flickr 25/9/09, and I was happy to see that it's based on the Dutch letterbox design on this site. With its external height at the back of just over 22 inches (400 mm), this is quite a squat design and sort of midway between the letterbox and my low-profile box shown lower down the page. A very nice box, with an interesting extended ledge design.

Hawk Conservancy Trust, near Andover, Hampshire, S England

Tawny Owl box in the Trust's grounds.

No further details. Material appears to be heavy-gauge plywood.

Tree attachment: nailed back bar.

Website

Photo © John Baker

Another nice, simple box design with ample proportions. Would be improved by a ledge.

KauzCam, Kempten-Oberallgäu, SE Germany

Tawny Owl box

Owner: Thomas Blodau, Fritz Markert (shown in pic).

Dimensions: 40-50 cm inside diameter x 60 cm high (ca 16-20 in x 24 in).

Materials & constrn: timber, barrel-type construction (shown at right), held together by steel bands.

Tree attachment: Two stainless steel bands welded to back of box.

Camera: IR, since 2006.

Webcam page (german only)

Located in a secluded wood, with its ledge, original design and sheer size this has to be a favourite.

Construction details (but no plans) given in Kauzcam entry on Making Your Own page.

Kauzcam video pic taken on the day female began laying in 2005 shows how roomy this box is.

Barn Owl Centre, Gloucestershire, SW England

General owl box, including Tawny Owl. A design they now use on their own property.

Dimensions: 600 x 400 x 300 mm (l x w x h); 24 x 16 x 12 in. Weight: 15 kg.

Materials & constrn: timber; assembly appears to be with nails.

Tree attachment: nailed back bar.

Webpage (shop). This is also a sold nestbox currently available at £45 + £8 delivery here in the UK. There is also a conventional letterbox type, but the BOC is ceasing production of this model as of January 2007.

Discussed on page 4, this box has nice features but is on the heavy side. Strong reservations about using shallow boxes for Barn Owls have been expressed by another organisation (details here, my site). Photo © The Barn Owl Centre.

Aishe Barton Farm, Silverton, Devon, SW England

Barn Owl/Tawny Owl box

This is the nestbox sold by the Barn Owl Centre (above). So far the box has not been used by either local Barn or Tawny Owls, possibly because territories overlap.

Tree attachment: On platform made from horizontal battens resting in fork of tree.

Farm website

Unknown, Halle an der Saale, Saxony-Anhalt, Germany

Tawny owl boxes

No details of either box. The website (a community site) is difficult to make out/navigate for a non-german speaker! These pics found from a Google image search.

Halle website

Halle an der Saale is about 50 km northwest of Leipzig, in the old East Germany. The blue box is the one I first saw. Apart from its small entrance and lack of ledge, I find its original and homely design appealing. A thoughtful touch is the back-sloping roof, which keeps rain drips off the front. Right: interesting because box is attached to a building and it's being used.

Unknown, Germany

Tawny owl box, location not known.

Photo © by Gerd Rossen (webpage for his tawny photos)

Photo doesn't show whole nestbox. Included here because it does show the stout construction from plank wood and assembly with screws, plus that essential safety feature, a ledge, if rather small. A negative point is the roof, which extends too far and is too low over the ledge, creating potential headaches for landing owls.

Gerd has a large collection of very good wildlife photos. Perhaps start here on his "About me" page.

God's Own Clay, Kent, SE England

Tawny Owl box (simple low-profile type)

Owner and maker: me.

Dimensions: 11 in x 15 in x 13 in high to inner ceiling panel.

Materials & constrn: tongue & groove pinewood, screw & glue assembly

Tree attachment: cord through two back battens

Camera: IR, starting 2007.

Website: Right here.

Designed to be as unlike the standard UK chimney-type as possible and create a pleasant space for female and chicks. Left pop-up pic (200 kb) shows the nestbox in its woodland setting. A feature of this box is its low door, about 5" above the base, which allows observation of the owls. It is not advisable to place it lower as the chicks would be at risk. Right: Box interior. Protruding bolt ends have been taken back since photo was taken. Constructed Oct 2005.

June 2008: After a second successful season, this shallow box is allaying my worries about its safety for tawny chicks, which show no sign of wanting to emerge before fledging. The low barrier under the door is also turning out to be enough to stop nestlings falling out accidentally. (But you should heed the warning by the Barn Owl Trust (Devon) about the use of shallow boxes for Barn Owls. For details and a link, start on page 4 of this Nestbox section.) For more on this box see Adding a camera and the Tawny Owl Nesting Diary 2008.

God's Own Clay, Kent, SE England

Tawny Owl boxes (dutch letterbox type)

Owner and maker: me.

Dimensions: approx 22 in (back) x 14 in x 14 in (larger box made to the original design) and ca 12 in front to back (smaller box)

Materials & constrn: composite 5/8 in wood strips between veneer sheets. Screw & glue assembly.

Tree attachment: cord through two back battens.

Camera: none planned.

Website: here. Extensive construction details start at this anchor on page 4 of the Nestbox section.

NOTE: One wouldn't normally choose a veneered material to make a nestbox, but some nice boards left from another project were in my attic. With a waterproof finish they should be ok.

These two boxes (left in the pic above) are my take on the very nice Dutch letterbox design at the top of the page. The third box in the photo is our main nestbox, described in the previous entry. The pic above right shows the second dutch box, for which I reduced the front-to-back size by about 2.5 in (6 cm) after making the first to the original dimensions. My additions to the design were the ledge and a window below to allow easy bino checks on occupancy from the ground. We found the slimmer design to be perfectly sized while also easier to put up in the tree as it's lighter and less bulky. So far no breeding attempts, but the larger box is being used as an occasional roost by a solitary male. We're delighted with these handsome-looking boxes and look forward to successful use by breeding owls. Constructed January 2008.

Plastic containers as nestboxes

This Barn Owl Conservation Network Forum thread, Plastic drums as Barn Owl nestboxes, has quite a bit of information on this. Point is, tawnies seem to like them. Here's an extract from a contribution by Vince Cartwright: "these have proven to be highly sucessful not for Barn Owls but for Tawny Owls and Kestrels, they have been up since 1998 in Oxfordshire and Buckinghamshire. Tawnys took to them right away producing broods in the first year the boxes were installed, in appearance they are very similar to an std Kestrel nestbox, the size and depth means that they are easy to install and check, at this time april 2002 i currently have two pairs of Tawnys on eggs in these boxes".

Aug 2007: Hoping to have more some time on these water softener drums, where to get them and how to attach them. Meanwhile here's a photo, kindly supplied by Vince, of tawny chicks in one of the drums.

Checking through the forum thread, it seems that condensation and wetness due accumulated chick droppings are not a problem in these containers provided that a sufficient depth of wood chips is provided. Be especially careful to find a fully shaded location for plastic boxes to avoid any risk of the interior overheating.

Dani Studler in Switzerland has a large number of these blue containers out for his owls and finds them to be very popular. I'm going to do a page soon on his nestbox project — when it's complete it'll be linked here.

Needless to say, if you use drums or cans that have been used for chemicals, be sure to clean them out very, very thoroughly before using them for owls. This means at the very least hot water with detergent. Check by smell that the last of any organic residue has gone when you've finished. Probably also wise to cut the entrance and drainage holes and then leave to aerate for several months before using.

FOOD FOR THOUGHT -- US DESIGNS FOR OTHER OWLS

OwlCam, eastern Massachusetts, USA

Northern Barred Owl box

Dimensions: 14 in x 14 in x 28 in.

Materials & constrn: cedar shingles over pine plank, plywood roof, screwed. Instructions here (maker warns that it's very heavy -- 48 lb!)

Tree attachment: screwed through inside back panel.

Camera: b/w since 1998, colour added end 1999.

Box replaced by a marten-proof version in 2003/04.

Website

Owlcam uses an American-style letterbox with comfortable dimensions and the door at a sensible height. This is the mother in 1998. Note the climbing aid bars at right. The owner comments: "How does a 23-inch owl turn around in a 14-inch room? Slowly -- she sticks her tail up in the air, puts her nose on the ground, and does a klutzy pirouette. She performs this move .. a couple of times each hour as she changes her incubating position." In fact, as the video shows, a mother and chicks have plenty of room.

This Northern Barred Owl cam will be well known to many internet owl nest watchers. The box was put up in 1997, and the camera(s) ran from 1998 to 2003, when that season's chicks were taken by a fisher (marten) while the parents were out hunting. Since then the adults haven't used the box shown here or the marten-proof replacement that was put up later that year. There are numerous excellent sound recordings on a dedicated page and in the day to day reports. Nice "family tree" pics here. No archived footage, though; you have to get the 100-min DVD of the 2001 nesting activities. Owl watchers will look forward to the box being taken up by another pair of Barred Owls soon.

Jan 2007. The OwlCam DVD is five-star stuff, a must-have for any owl lover. Here's my review of The Hidden World.

Chris' Eastern Screech Owl Nest Box Cam, Austin, Texas, USA

Screech Owl box

Owner: Chris W. Johnson.

Dimensions: 8 in x 10 in x 15-16 in.

Construction: series of boxes starting 1998; appear to be timber. Highly complex!

Tree attachment: dowel across inside back lashed to tree

Owl part of website starts here Click on year you want to see.

The Eastern Screech Owl is smaller than Barred or Tawny, but this is a nestbox that's generously sized relative to the owl (8-9 in long). And my oh my what a box! It illustrates so many of the points I've been trying to make about boxes for tawnies that I hope to be able to look at it in more detail some time.

Druid Labs, New Jersey, USA

Barred Owl box

Owners: Mike and Cathy Carroll.

No construction details.

Tree attachment: nailed back-bar.

Website pages: A useful photo essay here on getting the nestbox up its tree in January 2004. A pro at work!

This handsome box appears to have been constructed, and was put up, by the Wildlife Preservation section of the Jackson Pathfinders, a local volunteer environmental organisation. No record of whether box has been used.

Index page

Next page: A look at approved designs, with focus on UK.

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You can't get much nicer than this! A rustic tawny dream retreat at Brow Farm, Ormskirk, Lancashire. The owners say it was their most successful nestbox for three years.

What others are using ...