Animal Angles: Prairie Dogs Under Pressure
by Ruth Tenzer Feldman
Cattle eat grass. So do prairie dogs, those burrowing North American cousins of ground squirrels. In 1902, a government biologist stated that prairie dogs could eat up to 75 percent of grasses on a cattle range.
That's when the real pressure began. Ranchers declared war on prairie dogs, shooting or poisoning millions of them, or burying them alive.
Recent studies show that prairie dogs and cattle can successfully share grassland, but the killing goes on. It's also hard to find prairie dog fans among those whose lawns and golf courses are invaded by these “varmints.”
Prairie dogs live in a coterie (family) with one adult male, several adult females, and their pups. Several coteries make up a ward of burrows. Wards then make up a town, which could take up hundreds of acres.
Today, less than about one percent of the prairie dog population and habitat remains. Most abundant of the five species is the black-tailed prairie dog (Cynomys ludovicianus), a brownish rodent about 38 cm long and weighing about a kilogram.
Some scientists think that prairie dogs are a keystone species, supporting an ecosystem on which about 200 species of plants and animals depend. These include ferrets, foxes, and eagles.
When prairie dogs are out during the day, a sentry perches on the burrow mound to watch for predators. Spotting danger, the sentry barks out a warning. This signal can distinguish between predators, including whether or not a person has a rifle. Town members dive into burrows and stay there until the sentry's “all clear” call.
Several groups hope to relieve the pressure on prairie dogs and find ways that humans and prairie dogs can coexist. If these groups are successful, that would be the best “all clear” call of all.
- What is the limiting factor to the prairie dog populations described in this article?
[anno: Humans, particularly ranchers, who have been shooting, poisoning, and killing the prairie dogs are the limiting factor.]
- How do you think that the situation for the prairie dog could be changed? What would be the benefit of changing the limiting factor currently faced by the prairie dog?
[anno: Answers may vary but could include that educating ranchers about the benefit of keeping the prairie dog populations would help keep the prairie dog populations healthy. With healthy prairie dog populations, the entire grassland ecosystem would be helped.]