Our recent fieldwork with eastern massasauga rattlesnakes in southwest Michigan had most of the attendees slogging through cattails and mud puddles in search of this shy and elusive snake.
The eastern massasauga rattlesnake Lisa spotted in Michigan--her first in four years of looking! Lincoln Park Zoo works with partners throughout the country to guide the recovery of this species, which is endangered through much of its range.
I’m always excited to start surveying in the spring: breathing in the fresh Michigan air, listening to red-winged blackbird songs and wandering around with my head down looking for snakes. For the first time this year I finally found a snake (after four years as the project’s coordinator, it was getting a bit embarrassing!), but really only got to spend about an hour surveying. That sounds bad, but it was really good news, as we found a record-breaking number of snakes—117 in total—which kept me busy processing them rather than surveying for them.
In the Ecolab, where snakes are temporarily brought for processing, my team would first try to identify them based on a PIT tag (a chip like a pet may have), which would tell us whether a snake had been marked in a previous study year. Recapturing these snakes year after year gives us very valuable data on survival, population size and whether the population is growing.
Researchers carefully collect data from an eastern massasauga rattlesnake. Information from Michigan will help zoo scientists restore the shy species throughout its range.
After identifying the snake and marking it with a PIT tag if it’s new, we spend time measuring and weighing the snake and determine its sex and age (young, juvenile or adult). We collect blood samples that we use to study population genetics, reproductive hormones and blood-nutrient levels, often in comparison with our zoo population.
Lisa applies nail polish to a snake's rattle. It's a clear signal that the snake has already been counted in this year's survey.
Our final step is to give each snake a “rattle-icure.” We use nail polish to mark each snake’s rattle so we can quickly identify that we’ve already processed it when that snake slithers off into the cattails after we release it. In all, the data we’re collecting is going to be invaluable for describing how this population of massasaugas are doing, information that should help us understand how to better monitor and preserve populations across the species’ range.
Lisa Faust, Ph.D., is the Alexander Chair of Applied Population Biology in the zoo’s Alexander Center for Applied Population Biology.