Deer Foods During Years of Oak Mast Abundance and Scarcity

Harlow, Richard; Whelan, James; Crawford, Hewlette; Skeen, John

Rumen contents of white-tailed deer (Odocoileus virginianus) during November and early December of 1966 through 1973 in a mountainous area of southwestern Virginia revealed that acorns made up an average of 76 percent by volume of the deer's diet when acorns were abundant. When a mast failure occurred, deer replaced acorns with large amounts of the leaves of prostrate evergreen plants and shrubs and mushrooms. Proximate analysis of rumen contents revealed that diets containing acorns were higher in nitrogen-free extract and crude fat and lower in mineral content. In mast-free diets both mineral matter and protein increased. Proximate analysis and in vitro tests of composite diets indicated that when mast was present the diets were more digestible and were higher in fat and soluble carbohydrates. A relatively low value of 1.5 kcal/g for estimated digestible energy in mast-free diets suggests that when deer must rely on this type of diet during the winter season, their energy requirement for maintenance may not be met. The addition of oak mast to winter diets increased estimated digestible energy to 3.1 kcal/g, or a level adequate to meet the maintenance energy requirement. A forage inventory in the major forest types indicated that mature stands of pitch pine-bear oak (Pinus rigida--Quercus ilicifolia) produced the greatest quantity of important staple foods for deer during late fall and early winter.

Deer Foods During Years of Oak Mast Abundance and Scarcity

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