habitat types. Habitat needs vary for individual bears depending on their age and sex. These 

 requirements may also vary annually with seasonal changes in foraging needs. 



Food 



The broad historic distribution of grizzly bears suggests adaptive flexibility in food habits of different 

 populations. Although the digestive system of bears is essentially that of a carnivore, bears are successful 

 omnivores, and in some areas may be almost entirely herbivorous. Grizzly bears must avail themselves 

 of foods rich in protein or carbohydrates in excess of maintenance requirements in order to survive 

 denning and post-denning periods. 



The search for food has a prime influence on grizzly bear movements. Upon emergence from the den 

 they seek lower elevations, drainage bottoms, avalanche chutes, and ungulate winter ranges where their 

 food requirements can be met. Herbaceous plants are eaten as they emerge, when crude protein levels 

 are highest. Tliroughout late spring and early summer they follow plant phenology back to higher 

 elevations. In late summer and fall, there is a transition to fruit and pine nut sources, as well as 

 herbaceous materials. This is a generalized pattern, however, and it should be kept in mind that bears are 

 individuals trying to survive and will go where they best can meet their food requirements. 



Grizzly bears are opportunistic feeders and will prey or scavenge on almost any available food including 

 ground squirrels, ungulates, carrion, and garbage. In areas where animal matter is less available, roots, 

 bulbs, tubers, fungi, and tree cambium may be important in meeting protein requirements. High quality 

 foods such as berries, nuts, and fish are important in some geographic areas. 



In the CYE and portions of the NCDE, huckleberries are the major source of late summer food for bears 

 that enable them to accimnulate sufficient fat to survive the denning period and enable females to 

 produce and nurture cubs. On the Eastern Front, graminoids, roots and corms, and fruit had the highest 

 percent volume and highest important values of all bear food categories of analyzed grizzly bear scat. 

 However, mammals, sporophytes, and pine nuts were seasonally important. Throughout the region, 

 bears also commonly feed on gut piles and animals wounded and/or lost during the fall big game 

 hunting season. This can be an important source of protein for bears. 



Cover 



The relative importance of cover to grizzly bears has been well documented. Whether grizzly bears use 

 forest cover because of an innate preference or to avoid humans is unknown. The importance of an 

 interspersion of open parks as feeding sites associated with cover is also important. 



Forest cover was found to be very important to grizzly hears for use as beds. Most beds were found less 

 than a yard or two from a tree. In the NCDE, researchers found the majority of radio collared grizzly 

 bears in the forest. It is possible that this was biased by daytime relocations and new techniques which 

 allow locating bears 24 hours a day could change this. In the CYE, grizzly bears made greatest annual 

 use of closed timber, cutting units, timbered shrubfields, and mixed shrub snowchutes. 



Other studies have shown an avoidance of timbered cover types. In a study done in the Swan Mountains, 

 three cover types found to be important to grizzly bears were non-vegetated/grassland types, avalanche 

 chutes, and open slab rock areas. While forest were found to be among the least statistically selected 

 cover type, it is important to note that nearly half of the radiolocations of marked bears occurred in this 



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