What Do Deer Eat?

This has got to be one of the worst Falls I have ever seen. It is so dry and hot for fall weather and all of this has taken a toll on plant growth. Just look for an acorn crop - there isn’t much of one and on top of that most of the browse, forbs and grass deer might eat is dry. Anyway with all the problems landowners do need to know what deer eat to manage for this important resource.
One of the best publications for plant identification in the Cross Timbers I own is “White-Tailed Deer: Their Foods and Management in the Cross Timbers.” This is a publication of the Samuel Roberts Noble Foundation and is probably the most valuable book anyone interested in deer management could have, but it also makes an excellent reference because of its color photos of area plants. In the front of this publication is an appendix that lists the species composition of deer diets from Summer 1985 to Spring 1987. This chart shows hundreds of plants and basically how much of them a deer eats.
The top plants for the fall and winter may surprise you at least they did me. Bromes and tall fescue can make up to 25% of the diet composition. These are the green grasses that you see growing mostly under trees and resemble wheat or oats. Two to eight percent of the fall diet can be made up of honey locust but not necessarily the plant mostly the seed pods. Osage orange or Bois d’Arc (horse apple) trees can make up 17% of the diet mostly for their leaves. Deciduous oak trees like post, red, blackjack all are very valuable in a deer diet most of the year but acorns can account for a significant percentage in the fall if the acorn crop is good. In 1985 42% of the diet was acorns but in 1986 only 1.5% was acorns, owing I’m sure to a bad acorn crop. Coralberry is a significant plant for the deer diet in the fall and winter of every year. As much as 31% of the deer diet in the winter of ‘86 was composed of coralberry. What is coralberry? Around here we normally call it buckbrush and it is a shrubby plant 3 - 6 feet in height found in woody to open sites. It produces a small fruit but for deer all the plant parts are like t-bone steak. Here’s one you may not ever guess that deer eat, mushrooms. Almost every fall deer diets will consist of 4-5% mushrooms and I guess they don’t have a problem with the poisonous kind like we do.
Lastly let me add that small grains (wheat, oats, rye, etc.) can make up a significant portion of deer diets especially in the winter. In 1985 these were 21.5% of deer diets but almost 0 in 1986 when other plants were available. I am constantly amazed at deer hunters and landowners who want to provide small grains as a source of nutrition in deer diets in hopes of having bigger bucks and does, especially trophy bucks. If you want to produce trophy deer, extensive deer habitat management is almost always more important and more efficient than intensive management i.e. planting small grains and providing feeders. Plus the management of deer habitat means that they get the nutrition earlier in the year when they need it to produce the big antlers and develop good body condition.