Keeping tabs on Prairie Rattlesnakes

BISMARCK, N.D. (KFYR) - Mike Anderson takes us to a rattlesnake den in south central North Dakota.

Dr. Matthew Smith has kept tabs on a population of prairie rattlesnakes in Emmons County since 2015, dispelling the fictional buzz long circulated in some circles that there aren’t rattlesnakes east of the Missouri River in North Dakota.

“It’s been six years since our first trip. And so, we just wanted to see just a general idea how numbers were. If they’re still reproducing, you know, what’s the size of the individuals,” said Smith.

In mid-May Smith and a few interested Game and Fish Department personnel decided to make a visit to the den before the rattlesnakes dispersed for summer.

“We hiked up to the dens and by 12:30 we had encountered and captured 22 prairie rattlesnakes. The most at this den since we’ve started going. There are larger dens that I know about west, but this is by far the largest number of individuals we’ve seen at one time at this den,” said Smith.

13 rattlesnakes was the high count on a previous visit to the den. Once the snakes are captured, the work begins.

“So I try to grab them as quickly as possible, get them in a bucket and then take one out at a time and work with it. I can take measurements. I’m getting pretty good at looking at a snake and telling whether it’s male or female. Sometimes when they’re in the tube, I’ll take blood. So we’ll look at some DNA and try to understand some of the ecology of the population through molecular means,” said Smith.

Smith says he gets a good idea how healthy the snakes are when capturing and handling them.

“There were a good number of babies from last year, so young-of-the-year, and there were probably three that had been born the year before that. So we know that there’s been consistent reproduction. The males were larger than I tend to see out west, so the males are in really good condition. There was at least one female that was pregnant, so we’ll have reproduction again this coming year and most of the females were in good body condition,” said Smith.

North Dakota Game and Fish Department conservation biologist Pat Isakson says snakes are an important part of the ecosystem.

“They’re both predator and prey and do a great job of controlling small mammal and rodent populations, insects as well, and then also are provided as prey for raptors and other things like that,” said Isakson.

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