​​1. Start With the Right Habitat
 

Site selection is more important than the box itself. Look for a large, open landscape such as a pasture, meadow, orchard, grassland, or lightly managed agricultural field. Short or grazed vegetation makes it easier for kestrels to find insects and small mammals.
 

For Mid-Atlantic installations, experts recommend placing boxes:
 

• At least 50 yards from a tree line, which may reduce access by woodland predators.

• Within approximately 100 yards of hunting perches, such as power lines, snags, isolated trees, or fence lines.

• Away from busy roads and other hazards where inexperienced fledglings could be struck or trapped.
   

Avoid placing a kestrel box in a wooded backyard, a dense suburban neighborhood, or an area dominated by tall shrubs and trees. (DNREC)
 

2. Use a Kestrel-Specific Box
 

A bluebird house or decorative birdhouse is too small. Cornell’s current kestrel-box plan uses approximately:
 

• A 3-inch round or 3-by-4-inch oval entrance.

• An interior depth of about 17⅜ inches.

• A floor approximately 9⅝ by 11¼ inches.

• A hinged side that can be opened safely for

  monitoring and cleaning.

 

Small variations are acceptable, but following an established plan is preferable to improvising.(Download a plan from NestWatch here.)

The box should also include:
 

• Untreated pine, cedar, or similar wood at least ¾ inch thick.

• A sloping, overhanging roof.

• Ventilation near the top.

• Drainage openings in the floor.

• A recessed floor and weather-resistant joints.

• A secure side door for monitoring.

• No exterior perch; kestrels do not need one, and

  an outside perch can help predators reach the entrance.
   

Cornell’s current plan includes a small interior landing block beneath the entrance, which is different from an exterior perch. (NestWatch)
 

Place a layer of coarse, untreated wood shavings on the floor. Kestrels do not construct a conventional nest, and the shavings allow the female to form a shallow depression that keeps the eggs together. Refresh the shavings before each breeding season. (DNREC)
 

3. Mount the Box Securely
 

Use a stovepipe baffle beneath the box with top screen to block hole

Predator guards are highly correlated with nesting success, and pole-mounted boxes should be far enough from branches, fences, and adjacent structures that predators cannot jump onto them. (NestWatch) A free-standing metal or smooth PVC pole fitted with a predator baffle is essential and offers the best protection from raccoons, snakes, cats, and squirrels.

​

Cornell recommends mounting kestrel boxes approximately 10 to 30 feet above the ground, with the entrance generally facing south or east and separated by about half a mile, because kestrels defend breeding territories. (NestWatch)  We recommend sturdy 4-by-4 posts and existing structures such as barns, but rough wooden posts and surfaces are easier for climbing predators to scale (DNREC)

The mounting system must withstand strong wind and allow safe annual access. A lowering pole, pulley system, or camera on an extension pole is safer than repeatedly carrying a ladder across uneven ground.

Never attach a box to a utility pole without permission or work near energized lines. (NestWatch)

 

4. Install It Before Breeding Begins
 

• Put the box up well before spring courtship so kestrels have time to discover it. Fall or winter installation is ideal in the Mid-Atlantic. At minimum, clean, repair, and refill existing boxes before monitoring begins in March. (DNREC)
   

• It may take several seasons for a box to be occupied. An empty box does not necessarily mean the design has failed; kestrels may already have another nesting site or the surrounding habitat may not support a breeding pair.
   

5. Monitor Without Disturbing the Birds
 

• Responsible monitoring turns a birdhouse into a conservation project. During the nesting season we visit each nest approximately once a week. (For boxes with cameras monitoring is ongoing, sometimes daily.) Once activity begins, check boxes every three to four days as feasible.
   

• Record adult activity, eggs, young, apparent failures, and the final outcome. We log all our data into the Cornell NestWatch program. 
   

• During each check:

  • Wait for the adult to leave voluntarily whenever possible.

  • Keep the visit under one minute.

  • Use a pole-mounted camera or mirror when practical.

  • Avoid cold, rainy, excessively hot, or otherwise stressful weather.

  • Do not check at dusk.

  • Do not handle adults, eggs, or young.Handling or banding kestrels requires appropriate state and federal permits. (NestWatch)
     

• Kestrel young normally remain in the box for approximately 28 to 31 days after hatching. As they become fully feathered, alert, and close to fledging, stop opening the box. Late inspections can cause young birds to leave prematurely. Monitor from a distance instead. (All About Birds)
   

6. Manage Competitors Carefully
 

• Other animals may investigate or occupy the box, including screech-owls, squirrels, European Starlings, mice, and native cavity-nesting birds.
   

• Do not remove a nest simply because it belongs to another species. Most active native bird nests are federally protected. An active nest generally must be left undisturbed until it contains no eggs or young and is no longer being used for breeding. When identification or legal status is uncertain, contact a state wildlife agency or qualified bird biologist. (U.S. Fish and Wildlife Service). If you notice starling activity, it is best to block the entrance until they move on.
   

• Do not use pesticides, poisons, glue traps, or mothballs inside or around the box.
   

7. Clean and Inspect the Box Annually
 

• Clean the box in fall or before the next breeding season, after confirming that it is inactive. Remove old material and inspect:

  • ​The roof, seams, and entrance.

  • Mounting screws and pole stability.

  • Drainage and ventilation openings.

  • The door and latch.

  • Predator guards and baffles.

  • Evidence of chewing, rot, leaks, insects, or repeated predation.
     

• The interior can be scrubbed with mild detergent and water. For heavy fecal contamination, NestWatch recommends a solution of one part bleach to ten parts water. Rinse thoroughly, allow the box to dry completely, and add fresh wood shavings before the next season. Never clean or repair a box while birds are actively nesting. (NestWatch)
   

A Final Checklist
 

• A properly managed kestrel box should have:

  • ​Excellent open hunting habitat.

  • A correctly sized, ventilated wooden box.

  • Wood shavings on the floor.

  • Secure mounting 10–30 feet high.

  • A predator baffle.

  • An unobstructed south- or east-facing entrance.

  • Safe access for monitoring.

  • Regular but brief inspections.

  • Annual cleaning and repair.
     

• Nest boxes replace missing cavities; they do not replace habitat. Protecting open fields, maintaining abundant prey, reducing pesticide use, and keeping fledgling areas safe are just as important as providing the box itself.