The bur oak (Quercus macrocarpa) is one of the most widely distributed oaks in North America. They grow in a variety of habitats but tend to prefer drier and cooler sites and seem to tolerate drought conditions better than other tree species. They can live 300-400 years and grow up to 130 feet.
When fire is excluded from prairies, bur oaks can be one of the first trees to encroach on the grasslands. Indeed, once the bur oak reaches about 12 years old, it can persist easily in frequently burned areas and was once an important component of oak savannas. These savannas once covered about 32 million acres in the Midwest but only about 6400 acres of high quality oak savanna remains. Today, bur oaks are mostly found around the edges of lakes and in the coulees that form as water descends on the edges of the Coteau.
Woodlands form in the absence of fire, with basswood, green ash, and hackberry often shading out young oaks, eventually changing the composition.
Acorns, in addition to providing the next generation of oaks, are eaten by a wide variety of birds, mammals, and even insects.