My daily life here in Sri Lanka is becoming less deliberate and more routine. I regularly count the frogs that have joined me in the shower, I have a go-to soundtrack that I listen to on the drives from Rajarata to Wasgamuwa and back, and I depend on the nearby chants of the Buddhist monks to act as an alarm clock (I wish those wake-up calls weren’t at 4:45am each morning, but I guess beggars can’t be choosers…). The temperatures outside have quickly risen, and these routines help me cope with the heat. The heat also makes the whole no-hot-water situation easier to deal with too. With the transition from the wet to the dry season, the rains have also mostly subsided, although that hasn’t seemed to have an effect on the humidity levels.
The dryer heat alters the daily movement patterns of the elephants too. We’ve noticed that elephants are almost impossible to spot before 2:00pm now, even in the morning when it’s relatively cool. We think they’re spending the heat of the day under tree cover in the forest where we can’t see them. The vegetation is so thick that most times after moving just a few meters into the forest, we completely lose an elephant. (On a related note, we’ve also noticed that elephants seem much more wary of the vehicle and more apt to move into the forest when approach, a possible result of the recent crop-raiding that has occurred.) So as we’re driving through the park, I’m sure that there are tons of elephants (…literally) that we’re missing just a little bit off the road. We sometimes hear their trumpets and rumbles, but if we can’t see them, there’s not much we can do. Decreased elephant visibility at Wasgamuwa and lowering floodplains in other parts of the island are signs that it’s about time to move to another fieldsite and meet some new elephants. Hopefully we see some old “friends” too.
Encounters with elephants out in the open are increasingly rare with the high temperatures. Male 012, 12 March 2019, Wasgamuwa National Park.
So I’ll cherish our last few weeks in Wasgamuwa, a place that I’ll always remember as being my first “real” start to fieldwork on my own. I’ll admit it: the adjustment to rugged field conditions was tough to me, as I think they would be to most millennials who suddenly find themselves without reliable internet for weeks at a time. But since then, I’ve embraced the experience and I now enjoy being able to put off emails and other responsibilities that rely on being tied to a computer (the catching up with all that stuff at the other end of the trip is another story though). I’m fortunate to surround myself with friends, family, and colleagues who are patient enough to deal with all of this, on top of my propensity to keep to myself even when I have no other excuse.
Despite the wane in elephant activity around Wasgamuwa over the past month, there remains one fact in life: everyone poops. And in fact, even when it’s hot outside, elephants will poop, and that fact is evident as we drive around the park. In the areas that they frequent, elephant poop is ubiquitous, and it’s important for proper functioning of the ecosystem. Wild adult elephants are estimated to produce over 100 pounds of poop each day, and because they are rather poor at digesting their food, all of this dung returns vital nutrients back to their enviornment. Whole populations of insects and other invertebrates depend on elephant dung, including some species of the infamous dung beetles in Africa, who lay their eggs in the stuff.
I’m especially proud of this photo I got at a zoo a few months before I left for Sri Lanka. I’ve concealed the elephant’s identity for his own modesty. And yes, I got strange looks from the zoo visitors who were around me.
And most of my friends and family know of my fondness for (elephant) feces. And this penchant for poop isn’t due just to it’s environmental importance, nor is it a result of all of the practical uses people have found for it (for those who are curious, you can use elephant dung to make paper products and generate energy, among other things). But it’s what scientists can do with elephant poop (and poop from other species, for that matter) that really sealed the deal for me. We can learn about an animal’s life from its poop, including its diet, genetic composition, microbiome, and other things. For our project, we’re interested in measuring hormones, the body’s chemical messengers that are important regulators of behavior, helping an animal cope with its environment. And yes, we can measure hormone metabolites in elephant poop (side note: we’re measuring the metabolites, not the hormones themselves, because like many other molecules in our body, hormones get broken down so that they don’t have longlasting effects).
I’ve shared this enthusiasm for elephant excrement with Sachintha and the rest of our field team too (poop pride is infectious, I guess, but in a good way). Any day that we get a fecal sample, we blast celebratory music from my phone as we leave the park for the bungalow. Recently, it’s been Queen’s greatest hits (both Sachintha and I watched Bohemian Rhapsody recently…we highly recommend it). So far, we’ve collected 29 fecal samples at Wasgamuwa, with everyone in the vehicle emitting silent cheers and exchanging excited looks whenever we see an elephant do his business. 29 samples may not seem like a lot for almost three months of work, but the stars have to align for us to collect a sample. First, for our project, the elephant has to be male and over ten years old, and we have to see the elephant poop himself—there are critical things we need to know about the pooper for our project (including age, body condition, and musth status), so we pass so many dung piles in the park that it crushes me to do so. Musth males also seem to poop less often, as they appear to be eating less during the day. Next, the act has to have been done in a place that we can get to it safely. That means poops in lakes or ponds are a no-go (the water would ruin the sample anyway), as are poops deep in the forest (it’s difficult to see or hear nearby elephants, and our escape routes are severely limited in the trees). And the elephants have to move away from the poop so that we can get it. Sometimes this is relatively easy, and other times we mark the GPS location of the poop and come back later (although we only have a six- to eight-hour window to do this…coming back the next day is not an option). And if we can have all these factors go in our favor, we can get a sample. We’re safe as we can be when we exit the vehicle, having special permission from Department of Wildlife Conservation officials to do so and having a park tracker with us at all times. But the work has its inherent dangers—recently we got within 10 m of a crocodile (don’t worry Mom, this species hasn’t ever killed a human), and I can’t seem to forget the giant python we saw on the side of the road last month in the park. The open plains can be deceptive too. On our last trip, we trekked through a seemingly flat plain over 150 m to get a sample, not realizing the field was a metaphorical and literal minefield of ditches created by large groups of elephants walking through mud. The short excursion resulted in me falling on my butt in the mud, our driver laughing as he navigated the landscape easily in a sarong and flip-flops.
Nimal and I after our trek through the elephant-print minefield. Not pictured: my butt covered in mud from my fall.
Look how happy our poop team is! Last week, we collected an unprecedented four samples in one day. From L to R: Sachintha, Dhanushka, Nimal (who may not be excited, but is instead questioning his life decisions that led him to hold a piece of elephant dung in his hand), and me.
And the story doesn’t end with collecting the poop on the ground, as there hasn’t yet been an invention of an easy-to-use hormone gauge that you can stick into a piece of poop to know the concentration of testosterone in that sample. For long-term storage in the field, samples have to be kept frozen, which means I had to buy a freezer for our samples (just imagine the looks I got when I told Nimal that this freezer was just for poop). Power outages are relatively common and unpredictable, and with too many thawings the hormone metabolites in the poop degrades, so we keep bags of ice around the samples at all times, even when they’re in the freezer. On the day we drive back to Rajarata each trip, I pack a cooler with the fecal samples, never having told our driver what’s in the cooler (I keep it in the back of the van in case he asks for a drink from it). The samples are then put in a freezer in my kitchen until they’re processed. This has been a hallmark of my kitchen freezers over the past few years…you never know when you reach in whether you’ll get a bag full of elephant poop or a frozen breakfast sandwich.
Recently, we found a grain of rice in one of the fecal samples we collected (that’s what the red arrow is pointing to). This is evidence that this elephant exited the park to forage on crops from nearby farmers.
And then the elaborate processing step begins. For five or six days, the samples are “baked” in individual paper bags at a low temperature (about 130ºF). Don’t worry, I don’t use my own kitchen oven for this…they make lab ovens for things like this. After the samples are sufficiently dried and there’s no more water left, each of the samples is ground into a fine powder using a sifter or coffee grinder (I’ve realized there’s a lot of kitchen−lab overlap after writing this…I’m always careful with labeling my equipment). This step helps remove any of the vegetation that’s in the dung, while increasing the surface area for the extraction step. During grinding, I have to be careful to wear a mask so that I don’t inhale dung dust. Despite the protective equipment, I still seem to develop a persistent cough shortly after grinding samples. I try not to think about it too much.
For anyone thinking I’m not dedicated to my PhD, I’d like to inform you that I’m in the middle of an hour-long coughing fit from airborne powder resulting from grinding elephant fecal samples. And I was using proper PPE. #PhDLife
— Chase LaDue (@ChaseLaDue) March 6, 2019
After carefully weighing each sample—now sufficiently pulverized into a powder—and putting it in a test tube, we add methanol to each sample and spin the tubes in a centrifuge for about 15 min. The hormone metabolites are drawn to the methanol near the top of the tube and all of the solid material collects at the bottom of the tube. We separate the liquid part from the solid in another tube, and voilà, we have fecal extract that we can analyze for hormone metabolites using a process called enzyme immunoassay (I’ll save that process for another post).
And so that’s from where my poop passion stems; it’s not some weird quirk, but an appreciation for the utility of the stuff. So next time you see an elephant poop (or any other animal, for that matter), don’t think “gross,” but instead, “science!”
Here’s a photo of a baby elephant. You earned it for putting up with the turd talk (okay, last poop alliteration, I swear). Wasgamuwa National Park, 20 Jan 2019.