Looking for cryptic animals…without location information

This week, Dispatches from the Field is excited to welcome our first guest poster of 2017.  Megan Snetsinger shares some stories from her often frustrating hunt for Butler’s Gartersnakes in the wilds and not-so-wilds of Michigan.  For more about Megan, check out her bio at the end of the post.

A snake in the hand is worth two in the bush…

I’m working on a research project about the Butler’s Gartersnake. As I’m currently in the writing process, it’s easiest to write ABSOLUTELY ANYTHING ELSE. So let me tell you about planning my last field season.

Studying an at-risk snake in Ontario can be challenging, due to the restrictions placed on even considering touching one. But in some ways, it’s also fairly convenient, because the province has a strong philosophy on maintaining a record of species presence. As my project mainly covers Ontario snakes, most of my field season prep consisted of drowning myself in permit applications. But we (i.e. my supervising committee) decided that it would be useful to include some American snakes from locations adjacent to the Canadian range. And thus began my quest to find Butler’s Gartersnakes in Michigan.

This quest almost immediately hit a roadblock – because there’s no database recording location information for reptiles in Michigan. And the Butler’s Gartersnake isn’t endangered there. It’s considered as much of a ‘throwaway’ species as the much more widespread Eastern Gartersnake, so even the herpetologists don’t put too much effort in recording where they’re found. I was on my own.

The not-so-wilds of Michigan

My first step was to check maps for potential habitat. Not a good beginning. Check out the stretch of Michigan across from Southwestern Ontario on Google Earth. Half of it is taken up by the sprawl of Detroit and the rest is a patchwork of municipalities and farm fields. Not that I’m unaccustomed to that kind of layout – take away the giant urban centre, and that’s what the Ontario side of the border looks like. As much as I wish this weren’t the case, the Butler’s Gartersnake populations don’t have access to huge swaths of habitat; they eke out their existence in whatever pockets are available to them. I had to go smaller scale.

Zooming in on land features, I tried to pick out any locations that might have potential. While prairie-type habitat adjacent to water is the best, I settled for anything that might have long grass. This had no guarantee of working. It’s tricky to identify long grass. And even when satellite imagery is up to date, mowing can happen at any time. And there was another problem. Many of the most promising sites were on private land, owned by … somebody. Usually a corporation of some sort, which isn’t identified on Google and isn’t apparent in the street view. Trespassing on these sites seemed unwise. I needed to limit my search to locations that had public access, or at the very least had a name and face attached so I could request access.

Using these criteria, I had a working list of definite and possible places to check out. And this is where I learned that you never ever ever escape permits in fieldwork. The sampling permit was a gimme, again because no one there seems to care overly much about the snakes, but everyone I asked required intensive access permits. But I am nothing if not tenacious, and by the time I set out for the field I was wielding a binder full of printouts.

Once in the field, it was Google Earth all over again, with the added joy of trying to look for animals that are evolved to blend into and move quickly in grass, and have a habit of diving under said grass whenever someone walks nearby. We usually get only moments to react to their movement before they’ve vanished. And if they do get under the grass, that’s game over. A lot of grass-stained knees were acquired from diving to catch snakes.

Spot the snake: Butler’s Gartersnakes are quite good at hiding in grass!

With less than 2 weeks to work with, we started in St. Clair, Michigan and worked our way south, checking off stops on my (increasingly dubious) list. Some places that seemed like sure bets (e.g. state parks with a lot of open, grassy areas) turned up few to no Butler’s, and some “mayyyyyybes” (e.g. a mostly-mowed municipal park with a little patch of longer grass) were my only successful locations in a given region. That’s not to say that all my questionable locations were winners. We went though a lot of ‘drive in, look around, drive out.’

Some of the larger locations, particularly the Huron-Clinton Metroparks, even had site ecologists who were helped by telling us what they knew about sightings on-site. One of the best location resources was the Detroit River International Wildlife Refuge. They were happy to help conservation research, and gave us access to many of their locations, also suggesting which of their sites would prove most fruitful to search. Really, everyone was very nice. While checking out one of the Refuge sites, we met a farmer who was interested in what we were doing and offered us access to survey his land if we wanted. It turns out that even though Michigan lacks the ecological infrastructure that Ontario has, cooperation is always what drives successful fieldwork.

And it all worked out. I would have liked to have found more snakes (more data is never a bad thing, and what I got was not enough to study Michigan snakes as a focal population in my thesis), but I got a smattering of samples covering the stretch of land I wanted to cover. So all you really need for successful field work is months of prep, great collaborators, and a fantastic field assisstant (thanks Tori!). It’s simple really…

Megan Snetsinger is a Master’s student at Queen’s University working in Dr. Stephen Lougheed’s lab. Her research is a population ecology study, using genetic methods to determine how and why Butler’s Gartersnakes are distributed across their range. Like any geneticist, she spends a lot of time in the lab, but the real joy of the process is letting out her inner 8-year-old when running around catching snakes.