Monday, March 22, 2010

Nutritious, Delicious Native Shrubs

With the official beginning of spring, it may seem like the worst of winter is past. But for mule deer and other big game animals, March is often the cruelest month.

Having starved much of the winter, many animals are simply too stressed to make it through spring--particularly if there is little forage available. (Learn how you can reduce that stress).

A healthy sagebrush ecosystem can provide the nutritious food that deer, elk, pronghorn and bighorn sheep need to make it through the winter. A landscape still covered in shrubs can often make the difference between a thriving deer herd a non-existent one.

Sagebrush is a protein-rich, highly digestible plant. Numerous studies have shown that sagebrush often makes up a majority of a deer's winter diet.

There are 16 species of sagebrush, and they vary in palatability for mule deer. But as Dr. Carl Wambolt of Montana State University notes, even the least palatable species are valuable as forage.

Sagebrush sticks out of the snow, so deer can browse on it even in harsh winters.

A healthy sagebrush ecosystem, though, consists of more than just sagebrush. Other plants help vary a deer's diet and provide additional nutrients.

Other shrubs--like bitterbrush (pictured above), horse brush, winter fat and salt brush--are an important part of a mule deer's diet. Bureau of Land Management botanist Roger Rosentretter calls bitterbrush "deer candy" and notes that it aids in the deer's digestion to have a variety of shrubs.

"A mule deer diet of sagbrush and a little bit of bitterbrush is high-quality winter forage," he says. "The deer prefer the bitterbrush but they will do very well if you have both. They compliment each other with proteins and nutrients. It also aids deer digestion to have both."

In a healthy sagebrush ecosystem, native bunch grasses cover the area between the shrubs. Unlike non-native cheatgrass, bunch grasses stand upright all year--even during periods snow, allowing deer to access them more easily.

Non-native cheatgrass exists as a monoculture. It can be eaten by deer when it greens up in the spring, but it makes it very difficult for deer (and other wildlife) to thrive. As is almost always the case: Diversity rules. A healthy sagebrush system has so many values for wildlife. By protecting and restoring this habitat, we can ensure thriving big game herds remain a part of Idaho.--Matt Miller

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