How the population cycles of prairie dogs affect livestock, wildlife
OSU Research Matters is a bi-weekly look inside the work of Oklahoma State University faculty, staff and students.
Black-tailed prairie dogs are native to the Great Plains, but Sylvatic plague (Yersinia pestis) is not. This disease was first introduced to North America in the early 1900s and only reached many regions of the Great Plains within the past 20 to 30 years.
This disease can wipe out 95% to 99% of prairie dogs in a landscape. In some landscapes, these population "busts" can be followed by rapid growth, leading to population "booms" that intensify conflicts with livestock. This destabilized system has negative effects on both livestock and wildlife, and understanding either how to stabilize these dynamics, or at least mitigate their effects, is a major priority for managers.
In this episode, Meghan Robinson speaks with Dr. Courtney Duchardt, an assistant professor at Oklahoma State University, who is studying these population cycles to evaluate their effects on associated wildlife, and explore management strategies to address these issues.
DUCHARDT: Rangelands – it’s a term that a lot of people aren’t familiar with. You might think cows, or you might just think a big blank question mark. But, rangelands are essentially anything that's not completely desert, completely barren ice, and completely forested. [It’s] anything we could graze with livestock, but it could also be grazed with native ungulates like elk or pronghorn or bison. So, in those systems, I generally study the communities of wildlife that live there and how they respond to disturbances, both those disturbances that humans do on the landscape. So maybe building or oil and gas, but also the natural disturbances that shape those landscapes.
ROBINSON: One rangeland species that Dr. Duchardt frequently studies is arguable the most polarizing – the prairie dog. You either love them or hate them.
DUCHARDT: I'm one of like four people that sits in the middle of that Venn diagram. Basically, you’ve got your ecologists that are like, ‘they're great, they're a keystone species, they're super important.’ And then you have ranchers, and then even folks working in urban developments that are like, ‘they're a pest, they're a varmint. We wanna get rid of them.’ And there's very little, those two groups agree on. I like to think that both are coming to the table with some really good points. They are a keystone species.
Some research that we did up in Wyoming, and we're now doing a little bit more here in Oklahoma, we found that when you remove prairie dogs, everything changes. You lose certain species of birds, you lose some of your predators. Badgers and foxes really rely on prairie dogs. When the prairie dogs go, so do the badgers, so do the foxes, but on the other hand, they do clip vegetation. They do remove some of the food for cows and that can be a problem. So, we just kind of have to figure out the amount of prairie dogs you need for wildlife, but not exceed our tolerances for livestock.
ROBINSON: Like most rodents, prairie dogs have population cycles. Over the last 20 years, these cycles have become boom and bust, as a result of the Sylvatic plague. About 99% of prairie dogs who are infected will die, leading to a population decline. These cycles can impact Dr. Duchardt’s research.
DUCHARDT: Actually, the first cycle that I observed was during my Ph.D. research where we were studying, we were trying to understand the different bird species that lived there. And I went out, and I started collecting data, and it was quiet. And if you've ever been on a prairie dog colony, they're never quiet. They're barking, they're talking. If the sun is up, they're up, and they're loud. And it was quiet, and it was eerie.
And so I was wondering what's going on, what we figured out in the next few weeks there was a plague event, and I was terrified. What about my data? What about my birds? What's gonna happen? But we realized we could actually learn a lot from those cycles. And so we've been collecting data long term there, and then now we've got some research happening in the Wichita Mountains here in Oklahoma, and then also the Kiowa and Rita Blanca National Grassland in the Panhandle of Oklahoma, where we're also trying to gauge these different cycles. So, at first, it seemed like a problem, and certainly it wasn't good for the prairie dogs, but we actually got to learn a lot from that natural experiment when the plague event occurred.