Sunday, July 3, 2011

How "Wild" is Wildlife?

South Dakota's Custer State Park was formed in 1912, largely through the efforts of Peter Norbeck, often known as the “Father of Custer State Park.” Today, the park encom-passes some 73,000 acres, 50,000 of which are classified as forested land. However, large wildfires have significantly affected 23,000 acres.

Even though some of these large wildfires occurred over 20 years ago, some of these areas have had little tree re-generation. We saw areas like this (right) and assumed it was damage from one of the four major fires during this period.

However, another answer for the damage to the trees may be billions of little beetles. Mountain pine beetle larvae feed underneath the bark, which hinders the tree’s ability to send nutrients from the roots to the needles. This in turn kills the tree and the needles turn from green to red to brown and eventually fall off.

The main technique that is proven to work in controlling this beetle is to maintain ponderosa pine stands at low to medium densities. Removing trees from a stand prevents it from being over-crowded. This may have been the reason for cutting a few trees near one of the overlooks.

But our post-lunch search for wildlife along the park's 18-mile Wildlife Loop continued.

From the park's brochure:
"Custer State Park is loaded with nature.... (E)xperi-ence the beauty and wildlife on a guided tour of the park’s Wildlife Loop Road....(P)articipants may observe bison, pronghorns, elk, whitetail deer, mule deer, prairie dogs, and coyotes" (custerstatepark.info).

Well, we were looking for wildlife, so even these descendants from the burros that provided rides to visitors to the top of Harney Peak fit our new definition of "wild" life. (The rides were discon-tinued years ago, and the burros were released into the park where they have become a popular attraction.)

We continued our drive through the park under picture-perfect skies—perfect for photographs, but at the time of day least likely to see wildlife in the park--midday.

Then we came upon this herd of bison. In 1914, Peter Norbeck purchased 36 bison to start its herd. By the 1940s, the size of the herd had swelled to over 2,500. The herd soon began to overgraze the park’s rangeland and the bison numbers were lowered. Each year during the roundup, the size and the structure of the bison herd is adjusted according to the predicted availability of grassland forage.
The spring birthing season rejuvenates the herd size toward 1,300.

We tried to imagine what 1300 bison racing across the plains would sound like. That must be quite a sound.

Content with having seen the most numerous residents of the park, we completed the Wildlife Loop with a brief stop along a shallow brook.

Wildlife or not, the Wildlife Loop is a beautiful drive.