Wednesday, May 14, 2008

Prairie Dogs

Prairie dogs at Devil's Tower National Monument.
In the early 1980s, I discovered an amusement park game called “Whack-A-Mole,” in which the player employed expert hand-eye coordination to whack toy moles on the head as they emerged at random from a cluster of “mole holes.” The whacking was done with a large rubber mallet, and when successfully whacked, each mole would emit a high-pitched squeak. Popular among all of my friends, the game was an excellent tool for diffusing adolescent aggression.

I haven’t thought about “Whack-A-Mole” for years, although a quick internet search indicates that it still exists. If I wanted to, I could rekindle my affection for it by playing online at a number of different sites. Next time I need to diffuse some adult aggression, perhaps I will . . .
You may be wondering what made “Whack-A-Mole” cross my mind. It certainly would not be environmentally correct to express ill will toward such an innocuous creature . . . especially in a nature column.

I started thinking about Whack-A-Mole during a trip to the Badlands of South Dakota earlier this fall. My husband and I spent two weeks in September and October road-tripping through the Rocky Mountains and the Black Hills. Badlands National Park was high on my list of things to do; we were fortunate to spend the better part of an afternoon there.

All of the information I had read insisted that a trip to the Badlands would not be complete without visiting Roberts Prairie Dog Town, which is located down a dirt road off the main road of the park. I was skeptical – I couldn’t imagine how a “town” made up of any sort of rodent would be anything but stomach-turning.

But we checked it out just the same. After exploring some of the rapidly-eroding ridges and canyons of the park, we pulled our car up next to a wooden sign that appeared to be in the middle of nowhere. The canyons were still visible behind us, but in every other direction there were only dusty, scruffy-looking plains.

Just when I was starting to think that the Prairie Dog Town had been shut down for the winter, I heard a small squeak, and a chubby squirrel-like creature popped up out of a hole in the ground only a few feet in front of me. Aha! A prairie dog. It was several shades of light brown in color, blending in perfectly with the dirt around it. Large eyes and a bushy tail made it appear friendly, but I knew better than to approach it. Despite short legs, its hind feet were quite large, adorned with long, well-developed claws.

I stood there quietly, wondering what to do next. I didn’t feel threatened -- it would be easy enough to walk away -- but the prairie dog was so fascinating, I was content just to gaze at it while my husband snapped photos. The prairie dog gazed back at me for awhile, but apparently accustomed to tourists, it soon began to nibble at the grasses growing at the edge of its burrow.
I scanned the land in front of me, looking for other inhabitants of the town. There was evidence of prairie dogs everywhere – a burrow, or the remains of one, every ten feet at least, the grass clipped low to the ground. Out of the corner of my eye, I saw another prairie dog pop up out of its hole to look around. I was too far away to hear the squeak, but soon enough, another one emerged from the ground close to me, and then another one, each making the squeaking noise I later learned was part of an elaborate communication system comprised of at least eleven different calls.

That’s when it occurred to me – the prairie dog town was like a giant game of Whack-A-Mole. But instead of attempting to whack each prairie dog on the head as it emerged from the ground, the goal was simply to anticipate where the next one would pop up.

Prairie dog towns can be found across much of the Great Plains, from the Dakotas west into Montana and Wyoming, and as far south as New Mexico and Texas. Within that range, however, their colonies cover only about 2% of the landscape. They feed primarily on grasses, especially in the spring and summer when each week a single dog can consume up to two pounds of vegetation (two-thirds to three-quarters of its body weight).

Prairie dogs generally live for three to five years, during which time a female can produce as many as 20 pups. Each will grow to an average of 12-17 inches long, and will reach a maximum weight of 3 pounds. With its twitching nose and tiny ears, the prairie dog can easily be described as “cute,” especially when it pops up out of the ground with a squeak.

A typical prairie dog town covers 5-10 acres of land, and is comprised of 30-50 burrows per acre. That’s a lot of holes in the ground! The burrow system includes mounds at the surface that serve as lookout points and tunnels 3-6 feet below that extend as much as 15 feet. There are several small chambers off of the tunnels, most used for sleeping and nesting, plus one near each entrance where the prairie dog can listen for activity above ground.

If you’ve seen the movie “Caddyshack,” where burrowing rodents wreak havoc on a golf course, you might expect prairie dogs to be a problem in the Great Plains. But it turns out that their presence is actually a good thing. Prairie dogs help to maintain grasslands by preventing shrubs such as sagebrush and mesquite from taking over. They also help to decrease erosion: by burrowing and digging in the ground, they loosen the soil and allow rainwater to pass through it more efficiently. Furthermore, prairie dogs’ constant nibbling and clipping often improves the nutritive qualities of the vegetation.

They’re also really fun to watch.

by Kezia Bacon-Bernstein, Correspondent
November 2003

Kezia Bacon-Bernstein's articles appear courtesy of the North and South Rivers Watershed Association, a local non-profit organization devoted to the preservation, restoration, maintenance and conservation of the North and South Rivers and their watershed. For membership information and a copy of their latest newsletter, contact NSRWA at (781) 659-8168.

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