As far as staple foods, White Oak acorns, food plots and honeysuckle. I read a study once that stated on average during the winter months in the South, honeysuckle was approximately 40% of a deer's diet. From what I have observed, I would agree with this study. I'm sure it would depend on other available food sources, but that is a significant amount.

As far as seasonal (short time or very limited supply) food and depending on the area: persimmons, polk berries, honey locust bean pods, sugar maple leaves, mushrooms, kudzu, old orchards or fruit trees (apple, pears, plums) and crops before and shortly after harvest.

In the area I mostly hunt, honeysuckle would have to be at the top of the list as the most consistent, most used food source.