From the field!
By Seth Phillips
(left) Alates swarming on a Macrotermes mound (photo: S. Phillips); (below) an Issa chimpanzee termite fishing (A. Piel)
I climb on top of the termite mound. I scoot the ball of my right foot forward until it finds purchase, hold on to a nearby branch, then lunge my left foot up high enough to safely ascend the structure. Approximately 2 meters tall and 4 meters across at its widest, this giant lump in the ground resembles what might happen if one were to bury a Toyota Land Cruiser in the middle of the forest.
Instead, there are likely hundreds of thousands of large-bodied Macrotermes subhyalinus below my feet. Macrotermesare the largest termites in the world and are the preferred type for chimpanzees that “termite-fish”. Termite-fishing consists broadly of inserting a long vegetative tool into a passageway connected to the surface of a mound in order to catch the defensive soldier caste. If all goes well for the chimpanzee, these Macrotermes soldiers bite onto the tools with their huge, snapping mandibles and stay there until the tool is retracted from the mound and the hungry fisher-chimp consumes the crunchy bounty.
I’m collecting year-round data on surface conditions of termite mounds while also attempting to extract these massive insects as an Issa chimpanzee would (see video above). With these data we’ll have a better understanding of the availability and abundance of this resource year-round for Issa chimpanzees. You can think of it as somewhat analogous to how a primatologist collects data on the status of fruiting trees within a primate’s habitat. Except the ‘fruit’ of these mounds consists of pugnacious termite soldiers
snapping their oversized mandibles at you, which may draw blood if you’re not mindful where you rest your hand.
So here I am hunched atop of this earthen monstrosity with a 40cm bark tool in hand while doing my best impression of an Issa chimpanzee attempting to termite-fish. I scan the surface of the mound looking for any irregularities- a slim passageway, freshly-worked soil, a lost wing from a termite of the flying reproductive caste- anything that might indicate termites are close to the surface. Nothing. I scratch at the soil with my index finger attempting to expose a passageway as I’ve seen the chimpanzees do on camera-trap footage. Still nothing.
Had I not witnessed this same mound teeming with termite life during my last visit to the Issa Valley three years ago, I might be convinced there actually was a Land Cruiser under the earth. One day in 2018, I came to this spot and found the mound was blanketed with open termite passageways. From these openings, Macrotermes spilled forth in the thousands to release their annual winged-reproductive brood. A multitude of predators, on land and by air, restlessly struck at the emerging cloud of would-be kings and queens. Those memories are quite the contrast to the dry and dusty lump I sit atop today.
A lot has happened since the day of that swarm. I managed to advance to candidacy in my PhD program. My nieces and nephew were born, made chimp-like noises, and took their first steps. Some personal relationships intensified, while others dissipated. Viral case-rates spiked, plummeted, then spiked again. I lost loved ones and nights of sleep worrying for others. Businesses opened, closed, opened, on and on and on. By the time I was preparing to return to Issa, I was conflicted.
My time in the Issa Valley three years ago was one of the best years of my life. Witnessing wild chimpanzees is a privilege few get to enjoy and the interactions I had with researchers and field assistants from around the world are among my most cherished memories. But by August of 2021, after the tumult of the last couple of years, I did not want more change. I did not want to uproot the “new normal” I worked so desperately to achieve. I wanted stability.
Now it’s 2021 in the middle of October, typically the end of the dry season here in western Tanzania, but the soil atop the termite mound is still uniform in color and texture. After the onset of heavy rains, the termite worker caste gets busy connecting dozens of passageways from the interior of the nest to the surface of the mound. These entranceways create vulnerabilities to the colony that are promptly covered with thin veils of fresh soil—a trivial obstacle to a determined chimpanzee or even a lowly chimpanzee imitator. The surface of a mound may stay accessible to chimpanzees in such a state for weeks or months before the winged-reproductive caste emerges and disperses to establish new colonies. But not today. Today the mound is dry and seemingly inaccessible. I may be able to break off a few precariously built chunks of dirt as if it were loose concrete but it’s otherwise impenetrable to those without pangolin claws or perhaps a pickaxe.
These days I wake up at 6:30 and eat rice & beans for breakfast. I hike down the valley, I sweat, and I scratch at the soil atop of termite mounds. After eating more beans for dinner, I call my partner as she wakes up to the Californian sun. Some days I curse the chimpanzees for erratically ascending steep hills only to immediately descend into another valley, never looking twice over the mounds (or their inhabitants) that I long to understand. Nonetheless, chimpanzee behavior is not without its charming consistencies. Soon the torrential rains will come and perhaps these coy termites with them. Just not today. Today the surface of this mound is as lifeless as it has been every day since my arrival. An ironic but welcome answer to a prayer for stability.