Studying the struggling Okanagan rattlesnakes

Photo: Michael Dunn

Dana Eye is hoping to help save the Okanagan's rattlesnakes by studying pregnant females, a subset of the population which has been historically under-researched. 

For three years running, the Thompson Rivers University masters student has been tracking pregnant snakes in the Osoyoos area, running her program out of the Nk'Mip Desert Cultural Centre. 

"Most of the research used to focus on male rattlesnakes, and in 2017 I kind of delved into pregnant female rattlesnakes, really the first study in over 30 years in B.C.," Eye said. 

"I've been radio tracking rattlesnakes to understand their movements, how far they go from their dens once they emerge in the spring and more importantly where do they give birth."

More information about these birthing sites may help ecologists preserve areas that might be ideal for rattlesnake denning. 

"To date, I've tracked 24 pregnant snakes, and I've been able to locate 14 gestation sites," Eye said. 

Rattlesnakes give birth to live young, unusual for reptiles. They put a lot of energy and time into their babies, similar to mammals, which is both an interesting aspect to the snakes and an unfortunate pitfall for a struggling species.

"It takes a lot of time for them to grow and replenish their population," Eye explained. "They give birth on average every two years, some every three. So that's kind of not great when you think of that rate ... and when they do give birth, it's maybe three or four young, and of course not every one of them survive."

This year, five of the original snakes she studied in 2017 returned to their original den site. 

"I was able to show they actually return, it's not just a random site that they come across and give birth there, it's something more special than that," Eye said. "That's pretty important in the rattlesnake world."

Eye works closely with another researcher Jade Spruyt, who has been studying pregnant rattlesnakes in the White Lake area. Spruyt also studies road mortality, a major threat to the animals. 

"She has found these gestation sites right beside the road, less than a meter away, in actually artificial structures," Eye explained. "So that's concerning, because you have mums hanging out there, she gives birth, and the babies are hopping out into the road and they get hit."

Eye hopes her research will extend protections already given to this vulnerable animal. 

"Having a better idea of how we can manage the species and conserve it is really important. Without having this information, we're only getting part of the puzzle," Eye said.

"Going forward, we need to protect more than just dens ... these sites that they are giving birth at could be just as important as their winter dens."