Predators
Tips on how to deal with common nest-box predators.
Squirrels
Raccoons and Cats
View Types of Predator
Guards
View Predator Guard
Plans
What to do about
Predators
Although birdhouses
serve the wonderful purpose of providing nesting opportunities for many native
birds, they can also provide easy targets for predators and unwanted
competitors.Common predators of nest boxes include raccoons, snakes, cats, and
squirrels. For years, nest box providers have been inventing ways to fortify
their nest boxes against these predators. Here are some tips to help you thwart
common nest box predators.
The most passive way to prevent predation
is to avoid placing nest boxes in areas where predators are prevalent. But,
because some predators are prevalent everywhere, this is often easier said than
done. Protect your cavity-nesting birds by placing
predator guards around your nest boxes.
Squirrels
In some regions, squirrels do great damage to nest boxes. By chewing
at entrance holes to enlarge them, they make it easier for themselves and other
predators to enter. If squirrels are a problem in your area, simply cut a hole
in a small rectangular piece of sheet metal, which is the same size and shape as
the nest box entrance hole. Attach the sheet metal to the front of the nest box,
aligning the entrance hole with the hole in the metal.
Raccoons and Domestic Cats
Raccoons and cats are abundant in both rural and suburban areas.
Raccoons seem especially difficult to deter because they are very intelligent.
Once they learn that nest boxes are a good food source, these nocturnal
creatures have been known to wipe out entire groups of nest
boxes.
In raiding nest boxes, both raccoons and cats will
leap to the top of the box, sit on the roof, and "dip" into the entrance hole
with their front paws to grab the contents.
Ways to prevent
raccoons and cats from raiding your boxes:
- Lengthening the roof so that it extends five inches
beyond the front of the box will prevent these animals from easily reaching into
the entrance hole.
- Mount your box high enough and away from trees so
cats cannot spring to the top of the box in a single leap.
- Attach predator guards to your boxes to prevent these
animals from climbing up to your box. Three commonly used guards are shown
below.
Predator Guard Examples
Stovepipe baffle
This device is the
most complex and perhaps, the most effective baffle. It is made of a stovepipe
or PVC pipe that encircles the nest-box pole. It is held in place by hardware
cloth and iron straps. Also, encircling the nest-box pole with metal sheeting
can be just as effective.
Noel predator guard
The Noel guard is a rectangular tube of hardware cloth stapled to the front of the
nest box. The edge of the tube has sharp points that will jab any creature that
tries to reach into the entrance hole; however, the nest-box occupants can
easily come and go.
Conical metal predator guard or collar

This guard works well for boxes that are attached to free-standing poles.
The collar is a circular piece of galvanized sheet metal that is placed around
the pole underneath the nest box.