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Northern Divide Bear Project - Bear Rub Objects

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Bear Rub Object Photographs

Bears rub on many objects: trees, signs, fence posts, power poles, outbuildings, cabins, and boulders. A typical bear rub tree is characterized by the lack of branches, smoothness, sometimes discoloration (due to dirt and rubbing the surface bark off the tree), presence of bear hair on the rub surface, and/or a lack of vegetation growing around the base of the tree where the bear stands. Some trees have a clear path in the vegetation leading to and away from the tree, sometimes displaying the depressions of bear footsteps (a bear trail) created by bears stepping in the same place as they walk up to the tree.

Bear Rub Trees

Pictures taken before trees were set up by survey crews. The picture on the left shows a rub tree without vegetation growing at the base under the rubbed side of the tree. All the pictures show rub trees with a discolored rub surface.

    three photos of bear rub trees

Bear Rub Trees Set Up (tagged and barbed wire attached)

Pictures taken after trees were set up by survey crews. Picture on the left shows a rub tree from the side with the trail on the left. The picture in the center shows a rub tree from the front. The picture on the right shows a rub tree from the side with the trail on the right. The picture on the right also shows two hair samples (glowing in the sun) attached to the barbed wire. The rub object survey crews will see the yellow tags on the sides of the tree as they travel down the trail and stop at the trees to collect the hair samples from the barbed wire. The barbed wire blends in with the trees and is hard to see. Trees were intentionally setup to be inconspicuous, which allows our study to be conducted without impacting backcountry users' wilderness experience.

    three photos of bear rub trees setup with barbed wire to collect bear hair

Hair on a Bear Rub Trees

When a bear rubs on a tree, its hair is caught by the rough or sticky spots on the tree. The picture on the left was taken before the rub tree was setup by a survey crew. The picture on the right was taken after the rub tree was set up, a bear has rubbed against this tree and left a hair sample behind.

    bear hair on the bark of a bear rub tree bear hair snagged on barbed wire attached to a bear rub tree

Pack Bump Trees

Pack Bumps occur when stock use the trail and the packs they are carrying bump in to the trees on the side of the trail. The picture on the left is a pack bump tree (NOT a bear rub tree). The picture on the right is a pack bump tree AND a bear rub tree. The smooth, light colored area is the bear rub area and within that area are marks on the tree where the stock packs bump the tree. The trail is located to the left of the tree.

    pack bump tree - not a bear rub tree bear rub tree that is also a pack bump tree

Bear Rub Power Pole

This power pole is a bear rub and a horse rub. The horses have rubbed on the pole so much it has worn away part of the pole.

    power pole that is rubbed by bears and horses

Bear Rub Posts

This post on the right had been used as a rub object and has been torn up a bit. After a crew set up the post with tags and barbed wire a bear rubbed on it and deposited its hair. The post on the right is a cabin support that is used by bears as a rub. It has been covered with old metal tins so that the bear doesn't damage the pole.

    gate post that is rubbed on by bears cabin post that is rubbed on by bears

 

red-la.gif (880 bytes)  Diagrams of Bear Rubs (and Pack Bump trees)

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