This episode of Nature Notes originally aired February 28, 2013.
Prairie dogs are an iconic figure in of most of the region where Nature Notes is broadcast. Prairie dogs keep grasslands diverse by their constant disturbing of the soil. Many species of plants only grow in disturbed soil—including many spring annuals that provided rich nutritious grazing to the buffalo and pronghorn before the grass greens up. Only on the rocky slopes of mesa and mountain can prairie dogs not reside. Everywhere else prairie dogs once abounded – billions once turned the soil in West Texas, now only a few million dor.
Prairie dogs are “varmints” to many country people. But prairie dogs are interesting, sophisticated, social animals that enrich and benefit the plants that grow above and around their burrows. If you wonder why there are so many mesquite trees in our pastures, the answer is likely that the mesquite-eating prairie dogs have been gotten rid of, and without them, the mesquite has no predator and, thus, thrives.
Prairie dogs live in coteries that have one male, several females (one the mother of the other females), and a half dozen young. The male dominates the coterie for a while, but then moves on as his daughters reach reproductive age. Another male then replaces him for the next generation. The females almost never leave, except when population pressures exceed the carrying capacity of the coterie boundaries. These boundaries remain the same for generations.
Male prairie dogs do not vocalize as often as females. Males have no blood relatives nearby, but females do, and to protect their shared genetics the female becomes the wary gender, issuing staccato barks at the approach of a predator. A single clear toned bark signals all clear. Territory boundaries are proclaimed with a quick upward leap and simultaneous bark. Researchers are discovering that the vocal communications can impart specific information.
Coterie members kiss upon meeting, gently locking incisors in recognition. When a non-coterie individual strays into foreign territory, a kicking and biting wrestling match results after belly-creeping and anus-sniffing. Coterie members often play-wrestle, and in the process reinforce the politics of dominance.
Prairie dogs will eat all of the aboveground parts of plants, but rarely graze a plant into the ground. Insects are occasionally eaten. When a coterie member dies, it’s usually walled off underground, but at times is eaten, for reasons unknown. In the spring a prairie dog only weighs a pound and a half, but by fall weighs three pounds. They don’t hibernate. During long cold spells they remain underground.
The burrows can be twelve to twenty feet deep and extend a hundred feet in length. Most have two entrances, one higher than the other to ensure good air circulation. The relative humidity and temperature are almost constant within the burrow. Dead end tunnels are excretory areas, and various chambers serve for resting, food storage and nurseries. The lower entrance drops straight down to a turn-around room three to five feet down. The high mound is carefully constructed from rain-wet soil carefully packed with the animal’s nose. The sun then bakes it as hard as pottery.
As long as a person does not ride a horse at a high rate of speed through a prairie dog town, the rodents are something folks like to watch – they are downright cute!
Nature Notes is sponsored by the Dixon Water Foundation and is produced by KRTS Marfa Public Radio in cooperation with the Sibley Nature Center in Midland, Texas. This episode was written by Burr Williams of the Sibley Nature Center.