Deer Browsing versus Grazing: What’s the Difference?
There’s plenty of green grass on my lawn and still lots of greenery in the irrigated hayfields at the edge of town. Nonetheless, deer are invading my neighborhood, chewing up flowers, nibbling new growth from roses and other ornamental shrubs, and gobbling leaves from nearly any variety of deciduous trees they can get their incisors around. All across the Rocky Mountain States, this is about the time that mule deer, white-tailed deer, elk, pronghorn and even moose sneak in to grab their snacks at the expense of suburban landscaping.
While all these species might find a meal in a yard at the edge of town, their preferences in forage are quite different. Biologists often categorize ungulates on a continuum between browsers and grazers. Browsers consume their plant matter in the form of leaves, bark and twigs from a variety of trees and shrubs. Moose are browsers, although they do eat some aquatic plants as well. Grazers are grass-eaters. Bison are a prime example of a grazing animal. Other ungulates may browse and graze. In North America, elk are the most versatile of our native ungulates, capable or either grazing or browsing. Mule and whitetail deer tend primarily toward browsing, but will also graze on succulent, broad-leafed plants, especially in the spring and early summer.
To a large extent, an ungulate’s range and habitat is tied to its eating habits. The eclectic elk can forage in a wide range of habitats, from grassy prairies to boreal forests. Bison are most naturally animals of the grasslands, but they can survive in mountainous areas, so long as there’s sufficient grass to graze. The selective eating habits of moose limit their distribution to areas that have abundant trees to browse. As they don’t graze, you’ll never spot a moose at home on the prairie.
Deer and the occasional moose frequent my neighborhood. Based on their eating habits, I don’t need to worry too much about my lawn. But if I don’t protect the shrubs, these browsers will prune them to smithereens.