While palatability, or taste preference, is difficult to measure in wild animals, most biologists believe that deer prefer acorns produced by white oaks over those of red oaks. This preference is attributed to the lower tannin content in white oak acorns.
What are tannins?
Tannins are chemical compounds produced by plants to discourage predators from eating their seeds, leaves and stems. Tannins in acorns have two basic effects on wildlife. First, they make red oak acorns taste very bitter (To see for yourself, peel a red oak acorn and pop it in your mouth!). Second, tannins can decrease an animal's ability to digest protein, and in severe cases, can cause the animals to loose more protein than it actually ingests. Deer are interesting in that they have developed a defense against tannins; their saliva contains compounds that bind to tannins, thereby reducing their negative effect on protein digestion.
Maintain a 3:1 mixture of red oaks to white oaks
Although white oak acorns are probably preferred by deer, that doesn't mean you should remove your red oaks. Acorns from trees in the Red Oak Group contain between two and four times the fat content as those from the White Oak Group. Additionally, red oaks produce larger acorn crops on a more consistent basis than do white oaks. In fact, since white oaks typically produce only moderate acorns crops, red oak acorns can provide your deer with the bulk of their energy intake most years. A good guideline is to maintain a 3:1 mixture of red oaks to white oaks when managing your oak stands.
Want more information?
Click any of the links below for more information about acorns and how to manage oaks to produce abundant acorn crops:
