Picture of striking falcon

The Raptor
Resource Project

P.O. Box 16
Decorah, IA 52101

Bob Anderson

Amy Ries
[email protected]

Picture: Welcome to the Build A Nest Box Page!
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 Falcon Nest Box Diagram (334 KB PDF)

Make sure to partner with state DNR officials or your state Nongame Coordinator. If you are unfamiliar with raptors, talk to falconers in your area before undertaking a nest box program. Please email Amy Ries, Raptor Resource Webmaster, at [email protected] for more information.

Diagram (334 KB PDF)

Peregrine falcons can be pretty picky about their homes. If the box is built incorrectly or installed in the wrong position, it will be much less likely to attract falcons. We have had success using a rectangular box roughly 23"x32"x20". The boxes should not be too deep; Peregrines are ledge nesting birds, not cave nesting birds. It is important to provide 3-4" of small, rounded pea gravel for nesting substrate. Make sure that the gravel is not too rough, or it may crack the eggs. The bottom of the box should have small holes drilled into it to allow for drainage.Nest box design will vary depending on the location and available mounting surface. We highly recommend utility smokestacks; however, a cliff will also work. Secure a mounting site before building your nest box. This will allow you to take site variables into consideration. Cat walks on utility stacks are generally accessible, but be careful! Peregrines prefer to nest in high locations near water. Take appropriate safety precautions when mounting the box (i.e. safety harnesses and ropes). Project members have survived some nasty falls. If you're not an experienced climber and the box is in an out-of-the-way location, get a climber to help mount the box. Better yet, pick a location that doesn't require climbing gear.Some tips:

  • If there are Peregrines in the area, let them show you where they want to nest. Observe them before installing a box. If it is spring, make sure they are not already nesting somewhere on the building. Peregrines are very aggressive parents, so leave the nest alone unless you're a professional with a reason to be there.We have successfully established pairs on smokestack catwalks. Place the box on the grate with the perch extending out into the air. This will leave room for maintenance workers.Don't put the nest box in areas where people go on a regular basis: above building entrances, on main walkways, on apartment buildings, etc. As noted earlier, Peregrine parents can be quite aggressive -- there have been reports of them "dive-bombing" building tenants who have gotten too close to the nest. 
  • Think about whether or not "whitewash" would be acceptable at your location. To maintain the enthusiasm of the owner and/or tenants of the building clean the box, replace the gravel, and remove mummified prey remains at the conclusion of each nesting season.

Sometimes a falcon will ground itself on its first flight. The unfortunate bird can be rescued and returned to the hack site, as long as it is not injured. During the first few days of the release it is very important not to disturb the young falcons, or they may try to fly prematurely. Do not disturb them unless absolutely necessary until they have been on the wing for a week.

Once a pair of falcons have discovered your box (we have had falcons take over a box within hours), contact your state nongame official if you haven't done so already! Work with him or her in the management of your nesting pair. Your nest box site will provide a known location to observe the falcons, and to determine their identity by reading their bands. If the falcons have a poor hatch, your nongame coordinator can help augment babies to the nest (young peregrines are put in the nest with hatched babies and adopted by the parents).