Nest Box Plans - The Kestrel Box

Kestrel Nest Box Plans

The Kestrel Box - an Arizona Non-Profit Corporation

Several people have asked for plans to build their own nest box. Below are some simple plans taken from a pamphlet published by the Arizona Game and Fish department titled "Build your own Kestrel Nest Box".

In Arizona and other mild climates, we recommend you place the box as early as October for the best results. For other areas we think that late winter or early spring is best, although because of scarcity of nest sites you might still have luck later on. Our experience (in Arizona) is that eggs don't come until mid-March or so, but the search for nest sites starts early (our female comes looking for the box in October or November) and mating begins as early as December or January.

See below for more tips about nest boxes.

About the Box | Field Notes | Nest Box Plans | Inside the Box

MATERIALS LIST

Sides (2): 1" x 8" x 15"
Front: 1" x 10" x 15"
Back: 1" x 10" x 25"
Top: 1" x 12" x 12" (Note I made mine 14" x 14" to get the most out of a 4' by 2' sheet of plywood)
Bottom: 1" x 9" x 10"
Cleat: 1" x 1" x 8"
2" wood or sheet metal screw (1)
Galvanized, aluminum or resin-coated nails

Instructions:

Saw the Lumber to the specified sizes.
Center the entrance hole 3 inches down from the top of the front and, if you're using planed (smooth) lumber, saw six 1/8-inch deep, horizontal grooves below the entrance hole on the inside to make it easier for the young birds to climb out of the box.
Center the sides along the back. Two or three 1/8-inch holes can be drilled through the top and bottom of the back to make nailing the box to the tree easier and prevent splitting the wood. nail the sides into place.
Add the front, then the bottom.
Nail the cleat to the back so the box top just slips under it. Use the two inch screw to hold the top in place.
Drill five 1/4-inch drain holes through the bottom of the box. An inch or two of coarse saw dust, shavings or dry grass can be placed in the box.
Use 3-to4-inch galvanized nails to attach the box to a pole or tree.
If you wish to paint or finish the box, be sure to use a nontoxic material. Light colors are best because they absorb less heat from the sun, keeping the box cooler and preventing the young birds from overheating.

Placement Tips:

(These tips are from The Kestrel Box, not the Arizona Game and Fish)

General Tips

Place the box early (see discussion above).
Place the box relatively high (depending on the surrounding terrain this might be 10 feet or 25 feet), but in a place that is easily viewable for your enjoyment, and someplace you can get to again for maintenance.
Clean the box between clutches. After each clutch you will need to replace the wood chips, and clean the box out. You might want to sand out the inside of the box to clean it.
If you tie the box to a tree, replace the ropes each year to avoid breaking (we are using a length of chain to avoid this).

Heat - how to keep the box cool(er)

Make the sides slightly shorter than the front by 1/4" to 1/2" or so in order to improve air circulation. This requires a second cleat below the lid to hold it in place (one cleat above and one cleat below the lid).
Place the box on the north side of a tree to maximize the shade it receives.
Use an over-sized roof (at least 14" by 14" instead of the 12" by 12" roof the plan calls for).
Paint the box white or some other light color to reflect the heat.
Saw 6 or 8 1/8" to 1/4" deep horizontal grooves in the front and the back panels (on the inside). In watching the nest box through a video camera we have noticed that these grooves provide a source of air circulation that the young huddle around to cool off. Alternatively, drill some 1/8" holes in the sides near the front and back for air circulation.

Bees/Predators

We have had a beehive take over our box each year since we put it up. Fortunately it has never happened while the birds are nesting, but one suggestion that we are trying this year is to put a thin layer of Vaseline on the ceiling of the nest box to discourage the bees. We hope it will do the trick.
We were clever on our first box and put in a fancy perch that the birds could land on before entering the box. This gave us several nice photographs as the birds would spend more time in the opening with the perch there. However, people pointed out that the perch doesn't help the birds, it only helps predators that might try to gain access to the nest. We don't have much in the way of predators in our neighborhood, but we have left perches off our subsequent boxes.

If you have a tip you would like to share or if you see a mistake we have made, please send us a note at the address below.

Send comments and questions to: dave@kestrelbox.org