A Series by New Scientists
We met at eight in the morning at a dirt parking lot just inside the national forest entrance. It was early May in central Arizona and an overcast morning turned into unexpected hail and brisk, hair-raising winds. Five trucks pulled up, representing federal, state, tribal, and university personnel about to embark on a field training exercise to survey for the rare narrow-headed gartersnake—a harmless fish-eating snake only occurring around mid-elevation stream areas of central Arizona and western New Mexico. In 2014, the species was listed as federally threatened due to population declines, habitat loss, and nonnative aquatic species that may eat or outcompete the snakes.
A population of narrow-headed gartersnakes was recently rediscovered and we were ready to embark on a census—a survey repeated over time to better understand this population’s attributes and distribution. “We’re probably not going to catch any snakes today with this weather, but we’ll head over to learn the sampling methods anyways,” said Sharon, the lead wildlife biologist. I gave a sly smile and hoped she was wrong.
Having grown up in Connecticut, I was used to splashing through creeks and muddy swamps, catching frogs and snakes in cooler weather. I remember a dreary spring day back home when the sky couldn’t decide between snow, slush, or rain. Yet nearly every log or stone I lifted sheltered a reptile or amphibian. I was optimistic we would find something interesting today, too.
After driving down winding dirt roads among a stand of ponderosa pines, we hiked across a mesic meadow to a stream and traipsed along its gentle bends until we arrived at a habitat transition zone—an area where elevation, plant communities, and soil composition change just enough for different species to occur, including narrow-headed gartersnakes. Just like that drizzly Connecticut day, we lifted rocks and woody debris to find animals taking refuge. “Gophersnake!” yelled one of the surveyors. “Got an elegans over here.” shouted another. Tree lizards scattered over rockpiles, tadpoles scooted in the creek’s calmer side-pools, and vibrant Arizona treefrogs huddled on nearby shrubs. As the weather cleared, we had great luck finding animals, yet still no narrow-headed gartersnakes.
Along the edge of the stream, I noticed a particular rock—not because of its contrast or mineral makeup, but because of its shape. The rock was wider and flatter than most. I pried up one side while peering underneath. It seemed the sunlight and my eyes hit the spot in the same instant. When I see a snake, any snake, I get an instant jolt of excitement, followed by a quick mental review of field guides, photographs, and past knowledge to identify the species. It all happens in the blink of an eye but feels like time stands still.
In front of me lay a coiled, drab gartersnake about to shed. But it was not like the other species we found that morning. This was it: the day’s first narrow-headed gartersnake, a juvenile male. “Got one!” I yelled. “Yes, Brian! Awesome!” and everyone gathered around to take a closer look.
Sharon handled the snake and deftly showed us how to take field measurements, assess health, and safely mark the animal for recapture purposes. Biologists do this to gain reliable information on a population and how it’s faring over time. This particular gartersnake had an important future in store for it.
And we got luckier as the day went on. Another flat stone yielded three narrow-headed gartersnakes—an adult male, sub-adult female, and a small male we estimated to be less than a year old. We were excited to find them together because they are assumed to be relatively solitary animals. (We later published these findings in a scientific journal.)
Along with the first gartersnake, we collected two others that day. The snakes were transported to the Phoenix Zoo for its conservation breeding program—a partnership among such organizations as Arizona Game and Fish Department and the U.S. Fish and Wildlife Service, with the goal of producing more snakes to replenish declining populations in the wild. This strategy has helped numerous species, from condors and oryx and black-footed ferrets to snakes elsewhere in the world. But this is a new strategy for narrow-headed gartersnakes.
My wildlife conservation and management research at the University of Arizona links field biology with zoo-based conservation, and particularly with the Phoenix Zoo’s conservation team. The zoo’s narrow-headed gartersnakes are managed in naturalistic settings—an artificial stream system, a specialized burrow for brumation (i.e., snake hibernation), and places to hide—all while allowing for natural sociality. As we learned in the field, some snakes are more social than we thought—a novel and exciting wave of science today.
Remote cameras have also been installed to candidly reveal the behaviors of these animals. We can observe the time of day (or night) they are most active, when they use water, and how seasonal changes may affect those behaviors. As we learn how they grow, socialize, and behave, we gain insight into conditions optimal for reproduction.
I take this zoo-based research and apply it in the field to gain a better understanding of when and where to look for more snakes. I’m also better able to approximate the ages of wild snakes based off growth data from the zoo animals. Subsequently, I can track and learn from gartersnakes in the wild and share that knowledge to enhance the zoo’s conservation efforts. What kinds of habitats do they prefer? How far will they wander from water? What are their daily movement patterns? This mutual information exchange promotes communication, fosters relationships, and advances conservation.
But how exactly does one track a snake in the wild? Most telemetry studies involve placing a signal-pulsing transmitter—typically built into a collar or harness—around the neck, waist, or legs of a target animal, such as a deer, lizard, or bird. A biologist then uses an antenna and receiver to home in on a specific frequency from the transmitter to discover what the animal is doing at a given place and time.
Unfortunately, a collar or harness doesn’t work on animals that would just slither out of those devices. For snakes, we need a method that is safe for the animal yet still generates important data. After scouring scientific literature, I came upon a study that used the universal fix-everything tool: duct tape. And it works: I use a thin band of tape to hold a small transmitter in place on the snake’s belly, safely past important organs but not as far as the tapering tail. Because snakes periodically shed, they effectively slither out of the tape—but not before I have collected important ecological data. Plus, I can retrieve the shed transmitter and repeat the process anew.
This method wasn’t without its trials and tribulations, though. Some Phoenix Zoo staff chuckled when they observed my colleague and I—straight-faced and serious—carefully testing an array of duct tape varieties for the perfect “scientific” balance between stickiness and safety. This meant we needed to ensure the tape would hold strong in inclement environments while not impeding snake movement or providing an obvious visual beacon to predators. A snakeskin-patterned tape did not meet our stickiness standards; we opted not to test a Justin Bieber portrait-style tape…
Not only do I get to apply science that directly aims to conserve a rare species, but gartersnakes in general are representative of many other animals. To a large extent, for example, they are dependent on water, like many other species. They typically prefer riparian areas and their diet can include amphibians, fish, and invertebrates such as worms and slugs. As we experience warmer and drier conditions, especially in the American Southwest, surface water is predicted to retract and important riparian habitat will likely dwindle. Understanding how gartersnakes respond in a changing ecosystem can serve as a “canary in the coal mine” for how other species might react. The science is important for humans, too, as water is as essential to us as it is to the snakes.
This project and others like it are beneficial because they enhance our understanding of the ecology and preferences of a given species or group of species. A better understanding of a wide variety of traits and processes not only makes for stronger science but tightens focus on effective conservation management strategies. In this sense, we’re gaining essential knowledge about a rare gartersnake so we as researchers, managers, and stakeholders can make more informed decisions toward conservation and recovery.
For me, the reward is both broad and personal. I work on projects that may be used as models for future conservation efforts with other species and collaborators, possibly resulting in additional conservation research between zoos, wildlife managers, and academia, including new opportunities for prospective students—something I strongly value. And I still get to splash around wet places working with the wildlife I grew up loving.
Header photo—riparian area in central Arizona—by Brian Blais. Photo of Brian Blais by Elizabeth Radl.