Problems & SolutionsPreventing Bears from Attacking Nestboxes

Preventing Bears from Attacking Nestboxes

QUICK TIP: Tough problem to solve!

CONTENTS: Recognizing a bear – nestbox attack, Preventing Bear Attacks, Peanut Pepper Recipe.

Pole bent by bears. Photo by Dave Richmond of Idaho.
Pole bent by bears. Photo by Dave Richmond of Idaho.

Recognizing a bear – nestbox attack: Bear populations are increasing, and with the loss of open space and access to garbage, bear:human conflicts are also increasing. A Black bear (Ursus americanus) may destroy nestboxes, tearing them up or mangling them (claw marks are often visible), and consuming the contents of the box (eggs and young.)

Bears are persistent creatures of habit and generally return to places where they have found easy meals. They have an excellent sense of smell. They are also very strong, and can easily bend a mounting pole or #5 rebar.

See more information on Predator Identification – Clues and Solutions.

Preventing bear attacks:

  • Hang boxes.
    • Use lifter poles like Linda Violett to hang them 15-20 feet high (see pages 66-68 of The Bluebird Monitor’s Guide). Also see David Gwin’s set up.
    • Hang them far out on tree branches, out of swiping distance.
    • Hang boxes from a thin, suspended cable (between two trees or poles), at least 8 feet off the ground, and at least 10 feet horizontally away from any pole or tree. The ends of the cable (e.g., with 10″ diameter metal disks that cubs can’t balance on or step over) need to be protected as bears can learn how to tear them down. Threading the cable through a loose three to four foot long section of 2″ diameter PVC pipe might also help.
  • Mount boxes very high (8-10 feet) on stout metal poles.
  • Mount boxes high on the side walls of barns or stables (where House Sparrows are not a problem.) Bears can not climb these wooden walls.
  • Remove bird feeders (which may be confused with nestboxes) when bears come out of hibernation, or bring feeders in at night.
  • Consider moving boxes (short-term solution).
  • Around houses: Don’t leave pet food or dishes out at night, clean barbeque grilles after each use and store them in a shed, don’t put meat scraps or sweets in with compost, stow bird feeders from April to November, keep garbage cans in a garage or shed or douse the garbage with ammonia to camouflage smells (Hartford Courant, August 2006).
  • Peanut Pepper: David Richmond has a Mountain Bluebird trail in Idaho (Rocky Mountain Blues). He has developed a simple but effective technique to prevent bears from destroying nestboxes and eating the contents. Prior to using this method, he lost about 20 boxes and broods to bears. As soon as nestlings hatch, place a gob of “Peanut Pepper” right in front of the nestbox post, on the ground. Repeat 2x/week until young fledge.

Peanut Pepper Recipe:

  • One extra large bottle of the cheapest peanut butter you can find from a warehouse supermarket. Empty into a large mixing bowl. Add:
  • 1-2 cups of cayenne pepper (bought in bulk).
  • 1/2 cup of red pepper flakes
  • Mix well with a large wooden spoon. Consistency will be gooey.
  • Lay out small pieces of Saran Wrap on the counter top (about 6″ square), then scoop gobs of the mix (using a ice cream scoop) onto the Saran wrap. Fold it closed and put it in the freezer. Once hardened, put wads into a sealed plastic bag.
  • Bring the frozen gobs (in an insulated container), unwrap (trying not to touch the mixture) and place one gob on the ground in front of each box with hatchlings in it.
  • Repeat 2x/week until young fledge.

Photos by Dave Richmond. Bear near nestbox. Photo by Dave Richmond.

As a first-time bluebird monitor, I am alternately mesmerized, mystified, and petrified. Until now, I never gave much thought about how the day-to-day existence of wildlife is so perilous and fragile. What an education!
– Donna Spray, Bluebird_L, 2006


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