Grizzly and Black Bear Sign
Types of Bear Sign
As bears travel across the landscape they leave behind signs of their presence. There are many types of bear sign, including bear rubs, bear trails, tracks, hair, scat, claw marks, bite marks, digs, wallows, beds, caches, and dens. Follow the link for information on how researchers use bear sign in population studies.
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. Hair can be an important source of information about a bear, including diet, and genetics.
Bear trails are a clear path of bear footstep depressions created by bears stepping in the same place as they walk. Bear rubs sometimes have bear trails leading up to and away from them.
Sometimes bears leave behind footprint impressions in the ground as they walk, such as a rain soaked trail (a). Sometimes they only leave behind a single footprint or track (b, c,d).
Bear scat is often encountered on trails and roads. Scat can be an important source of information about a bear, including stress, diet, and genetics.
|CLAW AND BITE MARKS
Claw and bite marks can be found on many things, including trees, signs, and fence posts.
Sometimes trees that have had bark stripped off have claw and bite marks on them from bears feeding on cambium. Follow the link for more information on bear foods.
Bears, especially grizzly bears, dig in the ground for roots, tubers, and squirrels to eat. Bear digs can be seen throughout occupied bear habitat but is most obvious in subalpine meadows. There is evidence bear digging activity influences the nutrient cycle and improves the soil for plants that grow in subalpine meadows (Tardiff and Standford 1998). Follow the link for more information on bear foods.
Bears dig wallows in wet areas and roll in the wet mud or snow which keeps them cool and may give them relief from insect bites. Bear trails and rubs are sometimes associated with these wallows.
Bears, like moose and deer, create shallow depressions in the ground to rest in. These beds may only be used once, or if there is a large carcass near by they may be used many times. Sometimes the bear will line the beds with branches or grass for extra warmth.
Sometimes when bears kill or find a large dead animal they will create a cache to hide and/or store it until they can eat all of it. Caches are created when the bear scrapes duff, grass, and branches surrounding ground onto the carcass. Sometimes there will be lots of scat and prominate bed(s) near the carcass if the bear stays in the area to feed on the carcass for days. Follow the link for more information on bear foods.
Bear find or create dens in the fall that they sleep in during the winter. These dens can be natural cavities in or under trees, logs, in rock crevices or caves, or holes they dig into the ground. Grizzly bear claws are highly adapted for digging and usually dig their dens into mountain slopes. Bears will line their dens with bedding material such as branches or grass. Female bears give birth in the den during the winter and tend to stay near the den for a few weeks after they emerge if they have young.
- Tardiff, S.E. and J.A. Stanford. 1998. Grizzly bear digigng: effects on subalpine meadow plants in relation to mineral nitrogen availability. Ecology 79:2219-2228