If you were creating a list of important wildlife plants for the Noble Research Institute's service area (a 100-mile radius of Ardmore, Okla.), oaks would certainly be at or near the top of the list. Oaks provide some aspect of food or cover for a multitude of "critters," including white-tailed deer, turkey, bobwhite quail, raccoon, opossum, crow, red-headed woodpecker, wood duck, fox squirrel and gray squirrel, just to name a few. Many of these animals depend on the energy-rich oak fruit the acorn for survival. Others consume vegetative parts such as leaves, new stems or buds. Some animals rely on oaks for nesting material, nest cavities or escape cover. The bottom line is that oaks are a very important piece of wildlife habitat.
Depending on the reference source, around 40 species of oaks occur naturally in Oklahoma and Texas. Many of these grow in Noble's service area. Oaks are quite variable as a group. Some species are found mostly in upland situations, while others are found mostly in richer bottomland areas. Some oak species thrive in dry soil conditions, while others grow in moist soil conditions. Some oaks grow into majestic trees, while others remain shrubby in stature. Oaks are capable of thriving under a variety of different growing conditions.
Oaks are classified into two major groups the white oaks and the red oaks. Species in the white oak group usually have lobed or unlobed leaves with smooth margins and produce acorns that mature in one growing season. Some common members of the white oak group include post oak (Quercus stellata), bur oak (Q. macrocarpa) and chinkapin oak (Q. muehlenbergii). Species in the red oak group usually have bristle-tipped leaves or leaf lobes and produce acorns that require two growing seasons to mature. Examples of common members of the red oak group are blackjack oak (Q. marilandica), Shumard oak (Q. shumardii), black oak (Q. velutina) and southern red oak (Q. falcata).
Acorns are probably the greatest single attribute of oaks that benefits wildlife. Unfortunately, oaks are generally inconsistent acorn producers on a year-to-year basis. Within species, and sometimes within groups, production is often a boom or bust situation. For this reason, it is best to have several different species of oak in the habitat to ensure some level of acorn production. In southern Oklahoma and North Texas, the difference in acorn producing characteristics between the white oak and red oak groups is significant. Unfavorable weather conditions during pollination and fruit set may adversely affect the current year's acorn crop, but the acorn crop of the red oak group that was pollinated and set the previous year may be unaffected.
For someone who preaches about the importance of diversity in wildlife habitat, it is difficult to single out an important plant or group of plants. However, I can't think of another genus of plants that affects the well-being of so many animals. If there were an "MVP" (most valuable plant) award for wildlife, the oaks would certainly be the top contenders.