ZOO-ology: Prairie dogs: Can you dig it?
Nov. 27, 2011 at 5:27 a.m.
BY JUDIE FARNSWORTH
On Sept. 7, 1804, Lewis and Clark were fascinated by the discovery of an animal they had never before seen.
Meriwether Lewis wrote in part, "Just above the entrance of Teapot Creek on the star'd side, there is a large assemblage of the burrows of the Barking Squirrel." William Clark wrote, "Contains great numbers of holes on the top of which those little animals Set(sic) erect makes a Whistleing (sic) noise and when allarmed (sic) step into their hole."
Those "barking squirrels" were black-tailed prairie dogs, then numbering many millions throughout huge western prairies.
Prairie dogs, members of the squirrel family, are very social creatures living in basic family units called coteries, usually one male with several females and young.
A group of coteries is called a ward and groups of wards are towns or townships.
Lewis and Clark, eager to capture some barking squirrels, set about digging and digging - all day - in the hard ground. Ten feet later and with no luck, they poured five large barrels of water into a hole before capturing a single prairie dog. It was eventually sent on a four-month journey by boat to President Thomas Jefferson. He was delighted and kept it with him for a time before sending it to his museum in Philadelphia. It lived out its life admired and content among other artifacts of the expedition.
The most remarkable features of prairie dogs are their vocalizations and architectural skill. As Lewis and Clark discovered, their burrows have steep tunneled corridors that may angle down 10, 15 or more feet then level off for another 20 to 50 feet. Many side chambers are used for storage, sleeping, nurseries, escape and even toilets. Listening posts near exits are guarded for security. A great deal of time is spent building and maintaining burrows.
Tunnel networks in a colony may include several thousand acres. Dome craters (mounds) around exit/entrance openings may be 8 to 12 inches high. Rim craters (mounds) are lower. Mounds are used as observation platforms, for flood control and for ventilation. Any grass/plants around the mounds are pruned (chewed) for better visibility.
The digging and pruning encourages plant growth that feeds many other animals. Abandoned tunnels are used by animals like burrowing owls, swift foxes, snakes and black footed ferrets. Many species, directly or indirectly, depend on prairie-dog towns for their survival.
The basic prairie dog defense is to shout and hide. They're ever on guard and run for their burrows when an alarm is sounded. When it's safe, an all clear bark is heard. Most amazing, many studies show what appears to be a very sophisticated animal language. Their unique vocalizations include different sounds for specific predators like hawks, coyotes, bobcats, eagles or snakes.
In addition, their barks may also indicate the size and distance of the predator. And. these clever little guys seem to have a ventriloquist-like quality to their alarm calls, which can confuse another animal.
There are various names for prairie dogs. French traders called them petit chien (little dog), settlers sometimes called them sod poodles.
Many call them fascinating. Their numbers have been tremendously reduced through hunting, extermination and habitat loss over the years.
They now occupy only about 2 percent of the land areas they once lived on. The prairie dog exhibit at The Texas Zoo allows you to see above and below the surface.
Judie Farnsworth is a longtime volunteer at the Texas Zoo specializing in educational programs.