The Search for Scat

One day, I fell into a frozen river while searching for otter poop in Missouri.

As I've alluded to in some previous posts, my master's research at the University of Missouri was on estimating the population size of reintroduced river otters in eight rivers in central/southern Missouri. We did this using noninvasive genetic sampling, i.e. picking up river otter poop at latrine sites (river otter communal bathrooms) and taking them back to the lab to pull DNA. It wasn't a very glamorous project, but we got some pretty good data and I got to learn how to do all those fun genetics techniques like extraction, PCR, electrophoresis, genotyping, etc. At first I wasn't very excited about the prospect of spending 2 years working in a lab, but it ended up being quite interesting.

It's really amazing how much information you can get from DNA, especially DNA that came from an animal's dropping. You can identify unique individuals, look at how genetic diversity changes across a landscape to identify barriers to dispersal and inbreeding, track lineages and evaluate relatedness of individuals within and across populations, and a whole lot more. Biologists are increasingly using this type of research on a wide variety of animals, even training scat-detection dogs to help them locate samples in the field. (I almost got a job once training these scat detection dogs in Seattle, after which I would have taken my dog up to Canada to help find wolf, cougar, and bear scat in the woods. I didn't get the job, but sometimes I still think about trying it out. Click here to read a National Geographic story about a friend of mine, Karen DeMatteo, who is working on a post-doc in Argentina, using her dog Train to sniff out scat.)

The best part is you can do it all without ever touching or harassing the animals, which can alter behavior and potentially cause capture-related mortality. As a matter of fact, it became a sort of running joke during my two years in graduate school that I was earning my degree studying river otters, and never ONCE did I actually see one. My friends would come back from their field work catching salamanders or tagging fish and return to joyously rub in my face that they caught a glimpse of an otter. Jerks.

Anyway, the field collection for my project occurred from January-April 2009. The Missouri Department of Conservation (MDC) hired a team of four technicians to cruise along the rivers finding latrine sites and collecting scat (and an especially disgusting substance secreted from otter anal glands, ingloriously dubbed "anal jelly"). We had to do this in the winter because otters tend to restrict their home ranges then, and because colder temperatures are better for preserving DNA. Unfortunately this meant canoeing on the rivers in sometimes extremely unpleasant conditions.

It's hard to tell since it's nice and sunny, but I'm pretty sure the temperature was about 5 degrees F. 

I only went out with the crew a handful of times, mostly to get a feel for the rivers and the scat collection process. They didn't need my help, and usually I think they found me more a hindrance than anything (I always sat in the middle of the canoe without a seat and without an oar, and I felt like they were chauffeuring me around). Most of the time we would start at daybreak, leave a truck at a drop-off point about halfway down the 15-mile river transects, and then get to the starting point and spend the day cruising both banks in search of latrines. We'd mark all the ones we found in the GPS and clear all the old scat off of them, then return in 6 days to collect all the new stuff.

Ice forming on my waders
 as I ran alongside

Ice dripping from the woods

As I said, sometimes the weather was extremely cold, and it made for unpleasant canoeing. We all wore neoprene coverall waders over jeans or thermal underwear so we could embark/disembark without getting wet, and because many times we had to drag the canoe through the shallows. However, this story takes place when temperatures were at their coldest: single-digits with below-zero wind chill. Since I couldn't help row, I had a very hard time keeping warm while I rode in the middle. Thus, if the banks were relatively clear, I would ask them to drop me off so I could run alongside. The waders made this kind of difficult, and I had to watch out for thorns and sticks that could easily tear holes in the soft fabric.

Look closely and you can see the ice crust,
and the path  being carved through it

Worse, one day during this cold snap, the river we were on finally started to ice over. It wasn't terribly thick, and the crew was able to barrel through it, carving a path through the thin crust. However, we finally got to a spot where the ice was just too thick. Despite the crew's attempts to back up and batter it at full speed, they were making very little progress. The brush on either side was too thick to allow us to drag it from the banks, or to carry it overland (plus those canoes are pretty heavy).

Enter me, scientist/fifth-wheel, wanting to stop being a hindrance and actually help out. Being one of the taller members of the team, I offered to wade into the deepening river and physically push the canoe through the ice while the rest of the crew walked the bank. So I stepped into the freezing water and took my position behind the canoe.

The water started out probably at the level of my hips, and it was easy to push it along the bank. But gradually the water grew deeper as the river narrowed. I could feel the iciness through the neoprene waders, glad that I had duct-taped all the little holes and leaks I had gotten from running along the brushy banks. Within minutes the water came up to my waist, my chest, until I was tip-toeing along the bottom of the river and watching it lap against the suspender straps.

And then, all of a sudden, the bottom seemed to drop out. My forward momentum was too strong to allow me to put on the brakes, and so my feet scraped along the last few inches of riverbed to kick pointlessly through the open water. I tried to cling to the edge of the canoe and hoist myself further above the river, but to no avail - water rushed in and flooded my waders with a sluuurrrrp.

Once that happened, of course, it didn't really matter if I got wetter. I threw caution to the wind and just dog-paddled through the river, pushing the canoe along. My legs felt like they weighed 100 pounds now that my waders were full of water; luckily, even though the fabric kept the water in, it was trapped there with the heat of my body, so it warmed up fast. But it was still uncomfortable as hell.

The icy stretch didn't last long as the river grew shallow again and the water ran faster. We were maybe only a half-mile from our drop-off point, so I bore the cold and discomfort without complaint - and I'll admit I sort of loved the extra respect my brave little endeavor had bought me with the awkward crew. As soon as we got back to the truck, though, I shed those waders as fast as I could - not caring if the two guys on the crew saw my gloriously stark-white thermal underwear, or the goose-pimpled stark-white flesh underneath - and put my warm, dry jeans and boots on.

the White River
in the spring

That may have been the last time I cruised the river with that crew. I went back with a fellow graduate student a few months later, during the spring, to help with her salamander project, and was able to see some Missouri rivers in all their glory. I have been to many states across the country, but I have yet to see streams that rival those in the Ozarks. They're crystal clear, with numerous natural springs to feed them, winding through deciduous forests and rolling hills and little Ozark settlements containing a unique and interesting breed of Americana humanity found nowhere else.

And they have river otters.

After being extirpated for decades, MDC brought them back, and Missouri now boasts a healthy population of them. My research enabled me to get a glimpse into their habitats and their secret lives, as well as create a mathematical formula to estimate their population from scat counts - completely noninvasive, so the otters never need be captured or disturbed - so that managers elsewhere can count poops and estimate how many otters are there.

So maybe I was stuck in a lab for two years, and got dunked in icy cold river water, and never saw the animal I was studying, but I'm extremely glad I got involved with this project.

Plus Mizzou has an awesome football team.