Recently, a dear friend came to visit us here in Uganda, so we decided to take the opportunity to visit Bwindi Impenetrable National Park, home to one of the world’s only two populations of mountain gorillas (Gorilla berengei berengei). The other population lives in the Virunga Massif, a volcanic range that straddles Uganda, Rwanda, and the Democratic Republic of Congo. There are only an estimated 880 mountain gorillas in the world, making them a critically endangered species. Threats such as habitat loss, political instability, and disease transmission have the power to wipe out these fragile remaining populations. Like chimpanzees, gorillas are very closely related to humans and can easily catch the illnesses we carry. Just one outbreak of a respiratory infection could be enough to wipe out an entire gorilla group, or worse.

Though this may seem like a bleak state of affairs, mountain gorillas are actually heralded as a conservation success story. Their numbers have increased significantly in recent decades as a result of conservation efforts linked to ecotourism. Tourists flock to Uganda each year to visit these famous residents. Now it was our turn.

The drive to Bwindi Impenetrable National Park was convincing evidence that this whole gorilla-tracking thing is not for the faint of heart. We crawled along muddy roads with steep drop-offs as we inched higher and higher into the mountains. Each hairpin turn revealed a new, breathtakingly beautiful view of the landscape. When we finally arrived at our camp, we were greeted by staggering views of Bwindi and the nearby Virunga Volcanoes, shrouded though they were in a chilly evening mist. We settled in with hot tea and dinner before heading to bed early in anticipation of gorilla tracking the next morning. Soon after going to bed, rain began tapping heavily on our tents. A downpour continued through the night. By morning, it trailed off to a drizzle as we excitedly ate breakfast and checked to make sure we were ready to go.

View of Bwindi Impenetrable National Park. Photo: Maureen McCarthy.

As we went on our way, our guide informed us that we would receive information on the gorilla group’s location from trackers who had set out early in the morning to find the group. Not long after beginning our trek, which began along a village trail shared with local residents, we received word that the gorillas were not very far off. Indeed, as it turned out, they were less than an hour’s hike away in an area outside the national park. Of course, gorillas don’t recognize national park boundaries the way we do, so it’s not uncommon to find them ranging beyond its borders. It began to look like we wouldn’t be hiking through dense forest at all.We set off in a group of eight tourists. Group sizes are limited to this maximum number in an effort to minimize stress to the gorillas. We weren’t quite sure what to expect. We heard that this trek was so difficult that people often had to be carried out on stretchers. This wasn’t just Bwindi legend. The day prior, a man was carried out of the forest on a stretcher because he was ill and the hiking proved to be too much. As we walked through the village, we saw children carrying another child in a wheelbarrow. Our Ugandan friend explained that they were imitating carrying a mzungu (white person) out on a stretcher. One of the local lodges even has a sculpture in the sitting room depicting the same scene. Just how difficult would our hike into this so-called “Impenetrable Forest” be?

As we hiked down a steep path through uncultivated hillside, we suddenly saw their hairy black figures emerge from the mist. Though I study our nonhuman primate relatives, I still have moments of awe and giddiness from time to time in their presence. This was definitely one of those moments. As we observed them, our guide informed us of the names of each of the gorillas. We eventually saw the entire group of fourteen. Gorillas live in relatively small groups consisting of a single or a few adult males, a number of females, and offspring. This is in stark contrast to chimpanzees, which live in fission-fusion communities consisting of anywhere from 20 to over 180 individuals.

We watched and followed them for one hour as they fed on leaves and dead wood, foraging slowly and relaxing. They were absolutely fascinating and majestic, and their habitat was absurdly beautiful and rugged. I marveled at it all and jokingly fancied notions of leaving the chimpanzees behind to study these lovely gorillas instead. All too soon, however, our time with them ended. Visits with the gorillas are limited to one hour, which may help lessen both gorilla stress and disease transmission risk.

Silverback male mountain gorilla. Photo: Jack Lester.

Young mountain gorillas feed on dead wood. Photo: Jack Lester.

On our hike back to camp, I couldn’t help but laugh about the setting in which we found the gorillas. We were prepared for a serious hike through the so-called “Impenetrable Forest.” Instead of deep forest, however, our visit with the gorillas was situated in steep hillside outside the national park in gardens and uncultivated lands. We were disappointed about not seeing more of the forest. Given our usual work studying chimpanzees in degraded and cultivated habitat, however, it seemed all too appropriate that we should find the gorillas in such a place. In the end, it did nothing to lessen what was a gorgeous and awe-inspiring day. Long live the mountain gorillas!

This post was originally published at Scientific American. 

Though my study covers a broad geographic area, encompassing the home ranges of numerous chimpanzee communities, we have focused substantial attention on one community in particular. This community serves as a focal point for ecological data collection and, when possible, behavioral observations. After months of tracking these chimpanzees in an effort to collect fecal samples, we’ve had the opportunity to repeatedly observe some of the individuals in this community. In such instances, it has been helpful to give them names rather than to refer to them as “the one with the scar on his back,” “the one with the freckled face,” etc. With that in mind, I introduce you to a few of the males we’ve met.

Mzee

His name means “old man,” which seems fitting given his elderly appearance and behavior. He’s a bit rough around the edges in the looks department…yellowed teeth, scraggly hair, and a weathered face. He also has what we refer to as shoulder pads, meaning the hair on his shoulders sticks up in a disheveled-looking way. In addition, he is easily distinguished from the other males by his pale, freckly face.

Mzee. Photo: Jack Lester.

Nonetheless, he has his charms and seems popular among the other chimpanzees in his community. Just check out the trust he has in fellow male Caesar as he grooms a…shall we say…sensitive area. (See photo below.) Males groom to cement social bonds, and such a delicate task surely requires great trust among friends or kin. Indeed, male relationships are very important among chimpanzees. Because they remain in their birth community through adulthood, males have long-lasting relationships with other males who are sometimes kin members. They often form coalitions with other males, which may thereby serve to aid a male’s status in the social hierarchy.

Caesar grooms Mzee. Photo: Maureen McCarthy.

Caesar

In stark contrast to Mzee’s eccentric appearance, Caesar is a very handsome chimpanzee with an extraordinarily hairy face. This characteristic always reminds us of the character from Planet of the Apes, hence the name.  He was one of the first chimpanzees we saw from this community, and his appearance left a strong impression. He appears to be of prime age, and we suspect he is very high-ranking. Only with more observations can we begin to tease apart the complexities of the social hierarchy with any certainty, however.

Caesar. Photo: Maureen McCarthy.

Porkchop

So named for his distinctive and bushy “porkchop” sideburns. The hair on his shoulders sticks up just like Mzee’s, leading me to wonder whether Mzee in his younger days bore a strong resemblance to the present-day Porkchop. Perhaps they are closely related.

Porkchop. Photo: Jack Lester.

Tyson

Caesar’s ally, and a charismatic male in his own right. He seems to be a nice fellow, though his typical relaxed facial expression portrays more of a frown than a kind smile. He also appears to be a prime male in his peak healthy years.

Tyson. Photo: Jack Lester.

Clayton

Clayton is a young adult male who seems to be attempting to work his way up the hierarchy. We have observed him at times interacting with the other males, while at times keeping his distance from the confident swagger of the older fellows.

Clayton. Photo: Maureen McCarthy.

Newton

This young male remains somewhat of a mystery to us. We have only a couple of good observations of him. From this, we’ve gathered that he is roughly in his late teens. On several occasions when the other adult males were present, Newton has been absent (or at least not visible to us). We hope to get to know him better in the coming days.

Newton. Photo: Jack Lester.

We are only just getting to know these males, so there is still much to learn. How are male relationships affected by this degraded habitat? For example, in larger forests where chimpanzee communities neighbor each other, males often patrol their boundaries to look for outsider males. Do these males engage in patrols, and if so, how? Unanswerable questions also come to mind. For example, what must an old male like Mzee think of all of the changes in his habitat since he was a youngster?  We can only speculate and enjoy the opportunities we get for a sneak peek into the life of a male chimpanzee here.

Porkchop, Tyson, and Clayton pant hoot. Photo: Maureen McCarthy.

This post was originally published at Scientific American.

Greetings are very important in Ugandan culture. Where we work, it is customary to greet those you encounter with a standard exchange in Runyoro, the local language here. For example, if we find a farmer working in his garden in the morning, we might initiate the following conversation:

“Thank you for your work.”
“Thank you for your work also. You are welcome here.”
“How was the night?”
“The night was fine.”
“What is the news?”
“No news.” (Note: It is important to respond in this way even if you do have very big news. You will go on to share that news later in the conversation, but for now, this is the standard reply.)
“How is this place?”
“This place is fine.”

This typically marks the end of pleasantries as well as the end of Jack’s and my conversational repertoire in Runyoro. From there, field assistant Nick continues the conversation by chatting with people and finding out whether they’ve seen or heard chimpanzees recently.

So began an unusual conversation a few days ago. In our unending quest to find evidence of chimpanzees, we turned onto a dirt trail that runs parallel to a surprisingly intact strip of riparian forest. A farm borders the forest strip, and our path led us to the home of the farmers who own that land. There we found an old man, a young man in his late teens, and several small children. Nick made some initial inquiries in Runyoro, and the young man, named John Mary, began to speak in an animated way. He switched to English and explained that this patch of forest belongs to his family. Nick implored him not to cut their trees. He replied that, ah no, they were cutting trees here some years back, but a couple of NGOs came to educate their family about the importance of protecting natural forests. They stopped cutting and hope to plant more natural trees there in the near future. He said that it is difficult to convince others to do the same. We shifted our gazes across the river, where people were busy cutting down trees for timber and to make way for crop fields. He said that the older landowners around here rent out their land for farming, and that as long as they receive their rent money they don’t mind what people do with the land. He expressed frustration that they don’t think about the impact of forest cutting on their children and grandchildren. They only want to get the money to fill their bellies now, because soon they will die and then they cannot eat, he said with a laugh.

Riparian forest is cut for timber and agriculture. Image: Maureen McCarthy.

The topic shifted to where he heard the chimps vocalizing that morning. We thanked the family and said our goodbyes, continuing along the path in the direction where he heard them. His words echoed in my mind as we went on our way. He is a great example of the power of education programs. His family stopped logging and is committed to the notion of forest conservation. All this talk of forests wasn’t mere rhetoric for our benefit. The evidence is easy to see—it’s leafy, green and, still standing tall in remarkable abundance.

A satellite image shows a network of riparian forest fragments in the study region. Image: Google Earth.

John Mary will leave his farm soon to resume his schooling in town. In the coming years, he will continue to fight an uphill battle to protect his family’s bit of forest. From impoverished local individuals to large multinational corporations, many have a stake in what happens to community-owned forests like these. Because of conservation organizations and people like John Mary, however, the value of natural forests to the livelihood of chimpanzees, humans, and entire ecosystems cannot be ignored.

This post was originally published at Scientific American.

It was a day off from the field, an opportunity for a bit of mental respite and physical relaxation. The quiet peace of the day was halted, however, when I received an alarming text message from my field assistant, Nick. In it, he relayed the news he’d just heard on the local radio station: a chimpanzee attacked a six-month old infant in a nearby village. The infant had been taken for medical care in town. The parents sought compensation from the government and a local NGO.

I thought back to our visit to this village just days earlier. While there, we met with the village chairman, who said that chimpanzees harassed people there but no one had been attacked to date. Though many trees have been cut for timber and to plant gardens, he assured us that community members were interested in reversing this trend through tree planting efforts. More trees would translate into more habitat for chimpanzees and, hopefully, fewer instances of conflict with them. The chairman and his wife already had some knowledge of chimpanzees, their relationship with the forest, and the need to protect them.

Now, just days later, I wondered…How severely was the child injured? What were the circumstances leading to this unfortunate event? How would an attack on an innocent child affect human attitudes toward chimps?

A few answers emerged when we visited the infant’s family. They said that the children were sitting in the garden, and that one child–aged 4 or 5 years–was holding the infant. No adults were around. (This is a common scenario, since children here often care for one another while adults work in the garden or engage in other chores.) A party of chimpanzees passed by the house on their way toward the forest. What happened next remains uncertain. When chimpanzees come near peoples’ homes, they are often threatened and chased. Whether the children did anything like this is unclear. What we do know is that one of the chimpanzees took the infant from the arms of the child holding her. The older child yelled for help and others, including several adults, came running. They chased the chimp, who proceeded to drop the infant in a cassava garden and run to the forest. Though the infant was injured, the injuries were not life threatening and the child is now making a full recovery at home.

The father explained that he wants to help chimpanzees, that he understands that they are losing their forest and that they are forced to come into gardens. He had no wish to retaliate toward the chimpanzees as a result of the incident. He also feels that people should receive at least some small measure of support if they are to protect chimps, however. Chimpanzees are a protected species, but what recourse do people have if chimpanzees take their food or behave aggressively? What protections are in place to compensate or aid people who suffer crop losses or personal injury? One family member suggested that there could at least be some funding in place for medical care in the event of an attack such as this. Hospital costs due to chimpanzee injuries, though rare, are prohibitively expensive for families such as theirs. We left their home feeling sympathetic for all involved, humans and chimpanzees alike. We could offer no easy solutions.

The truth is that there are no easy solutions. Educational programs can help teach people why chimpanzees behave aggressively and how to avoid conflict.  For example, there is a common belief among villages we visit that chimpanzees are becoming increasingly aggressive. On numerous occasions, people have suggested that we might be replacing their old friendly chimpanzees with mean chimpanzees. Children peer inside our vehicle when we arrive to see if there are angry chimpanzees inside, waiting to be led to their new home. In reality, the behavior of these same chimpanzees is altering accordingly with habitat loss and increasing human pressures, including frequent interactions with humans.

Humans and chimpanzees sometimes must compete for resources in close proximity. Photo: Maureen McCarthy.

Indeed, this sadly is not the first time such an incident has occurred in this region. Deforestation has led to chimpanzee habitat loss and fragmentation, with humans logging more of the forest on a daily basis. Forest trees are logged for timber and clear-cut to make way for agriculture, often for cash crops like sugar cane, rice, and tobacco. Human population growth accelerates environmental changes. Uganda is consistently ranked as having one of the highest population growth rates of any country on earth. With less forest and more cultivated crops, chimpanzees must forage in gardens and come into frequent contact with people.

In The Chimpanzees of the Budongo Forest, Vernon Reynolds (2005) described other instances of chimpanzee aggression toward humans in this region. For example, he reported that “a girl was attacked by a chimpanzee in the forest while she was with her mother and other women and children collecting firewood in the forest. The girl was bitten on the upper leg, genitals and hands, and hospitalized for two months. In revenge for this attack, the villagers of Kirima hunted and killed a juvenile chimpanzee in March 2002” (p. 218).

This example illustrates the bi-directional nature of the conflict. Humans become fearful, annoyed, and at times angry with chimpanzees who eat their crops and threaten their families. Chimpanzees, on the other hand, must forage somewhere for food in their rapidly changing landscape. When their perceived encroachment onto peoples’ land leads them to be chased, threatened, and aggressed upon by people, it comes as no surprise that chimpanzees sometimes behave aggressively as well.

Reynolds (2005) further described the chimpanzees’ situation in this way: “While their image in the eyes of local people is thus deteriorating, we should not blame them. Their actions are the direct result of human interventions in their habitat. The bad character now attributed to them in this area is wholly understandable; human beings equally threatened would react in similar ways” (p. 216).

From a biological perspective, this situation can simply be viewed as a competition for resources. It is to be expected when members of two species must compete for access to limited resources. From the human perspective, however, it’s a complex and heartbreaking situation. It is also a situation that reminds us of a shared trait that binds us with chimpanzees, one that we prefer not to focus on when highlighting our similarities with them. When families and livelihoods are threatened, members of both species can behave with seemingly ruthless aggression. Only by digging to the roots of the conflict can we begin to find solutions that will aid both chimpanzees and humans.

This post was originally published at Scientific American. 

Fresh nests and fecal samples. We knew the chimpanzees had nested nearby. Not having seen any signs of their continued presence, however, we assumed they had already left their nests and traveled elsewhere to forage. While examining the nests, we were startled out of concentration by a chorus of pant hoots just nearby. We looked in the direction of the calls. A few chimpanzees were in a fig tree not far away, eyeing us calmly as they stuffed figs into their mouths. We watched them for a few minutes until they climbed down from the fig and traveled along the ground through a nearby bit of forest. After we were certain they were gone, we continued checking for samples, including looking around the fig they left behind.

A chimpanzee watches us from a nearby fig. Photo: Maureen McCarthy.

This is not the first time we’ve been surprised by the chimps. Sure, they can be boisterous and loud. There are times when they’re downright impossible to miss. On other occasions, however, they are so quiet that we can pass right by them and almost fail to notice them. I often wonder how many times we actually have failed to notice them.

So went December. It was a busy month that brought lots of data, including a few surprise encounters with the chimpanzees. Surprises, though inevitable, are not the norm for us. Our direct chimpanzee observations often involve getting reports from farmers who tell us that the chimpanzees are in a nearby tree or patch of forest. When we find chimpanzees, we make every possible attempt to give them their space. We keep a distance of over 50 meters and view them through binoculars. We do not enter an area of forest when we know that they are just inside within 50 meters. Instead, we wait until we are reasonably certain that they have departed before entering to look for samples. This is very important since these chimpanzees are not habituated, meaning they are not accustomed to being followed by people for research or tourism purposes. (See another recent Scientific American blog for additional discussion of habituation and its role in our understanding of chimpanzees.) Habituated chimpanzees can be followed at close range and are—hopefully—undisturbed by human presence. Habituation is necessary to undertake long-term research that provides meaningful insights into the behavior patterns of chimpanzees.

Studying unhabituated chimpanzees means that I can’t rely on close behavioral observations for data collection. The chimpanzees I study typically flee if people come near. This is why I focus on indirect evidence like fecal samples to provide critical data. Even with only some behavioral observations, however, the chimpanzees provide a wealth of information for study. Their nests provide insights into where they choose to sleep, their feeding remains show us what they’ve been eating, their knuckle prints tell us which direction they’ve traveled, and their dung provides…well, all sorts of interesting information.

Studying unhabituated chimpanzees also means that I must take care to avoid causing undue stress to my study subjects. Because these chimpanzees live in small forest patches, they have limited space to flee if we come too close for their comfort. It is for this reason that we keep our distance and enter onto their turf only after they’ve left it.

Photo: Maureen McCarthy.

Given the importance of habituation for actually being able to watch the animals under study, one may wonder why I have chosen not to habituate these chimpanzees. There are several reasons. First, chimpanzee habituation is typically a long and arduous process. It can take one to two years or more, if feasible at all. As a lowly PhD student, I simply do not have the time or resources to undertake such a costly endeavor. More importantly, however, the risks of habituation for these chimpanzees may outweigh the benefits. Because they are often in conflict with the humans around them, being wary of people may actually work in their favor. The more comfortable they become with people, the more they may be at risk of aggressive encounters with their human neighbors. My colleague Matt McLennan (as mentioned in previous posts) has cautioned against habituating chimpanzees in our study region for ecotourism, saying that “habituation for tourism is inappropriate where apes and people live in very close proximity, for reasons that include increased likelihood of crop-raiding, risk of aggression toward local people and tourists by emboldened and/or stressed chimpanzees, and increased potential for disease transmission. Instead, habitat stabilization and enrichment must be the priority” (McLennan 2008, p. 52).

This study region is not unique in posing ethical concerns regarding the primates inhabiting it. Primatologists around the world must consider the ethical implications of various research methods, and design their studies accordingly. Just as lab scientists must consider potential risks to their study subjects in an effort to minimize harm, so must field scientists consider the potentially negative impacts of their research. Collecting data is only one aspect of the job. Personal, ethical, and emotional rewards and challenges are a part of everyday life. For me, this is what makes research an exciting, layered, and often imperfect experience.

This post was originally published at Scientific American. 

Humans are very poorly adapted to a chimpanzee lifestyle. I am reminded of this on a nearly daily basis as we trace the locations where chimpanzees have been hanging out. I regularly trip over vines and tree roots, slip off logs, and slide down muddy hillsides. I have tumbled to the ground no less than eight times in the past week. In between bouts of tripping, stumbling, and cursing, I find myself marveling at the strength and agility required to live in this forest habitat.

Chimpanzees are remarkably agile and well adapted to live in a variety of habitats in equatorial Africa. They are gifted climbers, and they also travel swiftly and gracefully on the ground as quadrupeds. In addition, they have staggering strength. A classic series of studies by John Bauman in the 1920’s demonstrated that chimpanzees have more than four times the strength of a human. While it is a difficult feat to measure this accurately, there is no doubt that chimpanzees are very strong indeed. Anthropologist Alan Walker described their strength as follows:

“On one occasion, I was minding my own business while walking along a forest trail when I nearly bumped into an adult male chimpanzee that was doing the same. The frightened animal swung at a nearby tree buttress root, making a resonating booming sound. After this display, the animal raced up the trunk and proceeded to shake branches high above me. When my heart rate returned to normal, I tried to imitate the chimpanzee by banging on the buttress as hard as I could. I could produce only a laughably feeble sound. Thus it was that I came to appreciate firsthand what many people know anecdotally—that great apes are immensely strong.”

(Note: If you happen to encounter an adult male chimpanzee in the forest, I would not advocate Walker’s response as your first recourse! Still, you get the idea.)

As I’ve struggled to maintain my clumsy upright posture, I’ve snapped a few photos of chimpanzees being their graceful selves in the trees.

A juvenile chimpanzee hangs out while foraging. Photo: Maureen McCarthy.

A juvenile chimpanzee swings between branches. Photo: Maureen McCarthy.

An adult male chimpanzee moves along a branch. Photo: Maureen McCarthy

Outside the forest, traveling hasn’t been much easier lately. In the past couple of weeks, we’ve had multiple vehicle problems. First, our beloved vehicle, Lucy, broke down just after a visit with friends in the next district over. It was the sort of malfunction that involved broken bits of metal falling onto the road and oil leaking out, leaving a disastrous Hansel-and-Gretel trail of vehicle mayhem behind. We had to call a tow truck to pull Lucy from a small dirt road to the nearest town. It’s not uncommon for trucks here to have short, snappy sayings painted onto the front of them. Our tow truck bore the slogan “Dangerous Toweling”. Somehow, this didn’t inspire my confidence. Nonetheless, we made it back to town without incident.

Lucy gets a tow into town. Photo: Maureen McCarthy.

It looked like we might be without a research vehicle for a week or two. Luckily, we were able to have our mechanic in Kampala send spare parts via bus the very next day. Jack put his mechanical skills to work and replaced the broken parts in no time. Thankfully, what looked like a serious setback was remedied in less than 24 hours.

Next, just days later, we got two flat tires. Unfortunately, both tires went flat on same day. The back right tire went flat, so we tested the spare in preparation to make a swap. The spare was also flat. Our portable compressor saved the day until we arrived back in town to get both tires repaired. These two tires are among the eight or so flats we’ve had in the past couple months. The good news is that I’ve never been so good at repairing flats. I have to admit that it might be time to invest in some new tires, though. Until then, we’ll keep chugging along, over forest tree roots and dirt road potholes alike.

Jack and field assistant Nick repair a flat tire. Photo: Maureen McCarthy.

This post was originally published at Scientific American. 

October 30^th marked the five-year anniversary of the death of my friend Washoe. Washoe was a wonderful friend. She was confident and self-assured. She was a matriarch, a mother figure not only to her adopted son but to others as well. She was kind and caring, but she didn’t suffer fools. Washoe also happened to be known around the world as the first nonhuman to acquire aspects of a human language, American Sign Language. You see, my friend Washoe was a chimpanzee.

Washoe was born somewhere in West Africa around September 1965. Much like the chimpanzees I study here in Uganda, Washoe’s mother cared for her during infancy, nursing her, carrying her, and sharing her sleeping nests with her. That changed when her mother was killed so baby Washoe could be taken from her forest home, then bought by the US Air Force for use in biomedical testing.

Washoe was not used in this sort of testing, however. Instead, Drs. Allen and Beatrix Gardner of the University of Nevada chose her among the young chimpanzees at Holloman Aeromedical Laboratory to be cross-fostered. Cross-fostering occurs when a youngster of one species is reared by adults of a different species. In this case, humans raised Washoe exactly as if she were a deaf human child. She learned to brush her teeth, drink from cups, and dress herself, in the same way a human child learns these behaviors. She was also exposed to humans using sign language around her. In fact, humans used only American Sign Language (ASL) to communicate in Washoe’s presence, avoiding spoken English so as to replicate as accurately as possible the learning environment of a young human exposed to sign language. Washoe began to acquire ASL signs at a young age, and her sign acquisition increased with a pattern bearing many similarities to a young human child’s language acquisition. She used these signs to communicate with humans and, later, with other chimpanzees who also acquired these signs*.

Washoe. Photo: Courtesy Friends of Washoe, used with permission.

Washoe’s use of ASL signs was groundbreaking. It altered our understanding of what it means to be human. Language was thought to have set us apart from other animals, making us unique among all species. Washoe and her chimpanzee family forced revisions of these old anthropocentric assertions. Later studies showed that all great apes—chimpanzees, bonobos, orangutans, and gorillas—can acquire aspects of human language.

As impressive as Washoe’s role in our understanding of human-ness was, it was not what impressed me most about her. After all, by the time I met Washoe a decade ago, her contributions to debates regarding human uniqueness were well established. Instead, as an intern and later as a master’s degree student at Central Washington University, I was most impressed by the kind of being she was. Here are just a few examples.

She had a strong sense of self. Washoe came to know many human friends at the Chimpanzee and Human Communication Institute (CHCI), her home for over 25 years. Students and interns come from all over the world to study and care for Washoe’s family. As such, Washoe was slow to warm up to strangers. Though she would often ask to see a new person’s shoes (she had an affinity for footwear and would always notice if caregivers had a new pair of shoes), it sometimes took months or more before she trusted people enough to share more in-depth interactions. The training process for chimpanzee caregivers takes several months as the chimpanzees come to know you and you learn how to safely interact through the fencing that separates them from you. For the safety of both, caregivers never penetrate the fencing or enter into the chimpanzees’ enclosures while they are inside. As a trainer for new caregivers, I witnessed Washoe’s relationships develop with numerous friends. In general, she and the other chimpanzees can read people like nobody’s business. She could size up a new person in an instant. Perhaps most importantly, she sensed whether or not you knew she was boss. She was the alpha (most dominant) chimpanzee in her chimpanzee and human family, and she expected to be treated that way. Washoe could easily spot a new person who appeared arrogant or who “talked down” to her. It wasn’t a good way to earn her friendship easily, and subsequently, newbies usually learned quickly about the rules of chimpanzee society. It was always best to greet Washoe first, to serve her dinner first, and to leave a little extra so she could be sure to have a bit more if she wanted it. These acts were not indications of favoritism. They were simply ways of taking the chimpanzees on their terms, of recognizing that Washoe was alpha and that alpha status in chimpanzee society affords certain advantages. The other members of her chimpanzee family also understood and expected this.

She drove a hard bargain. Once, after some maintenance men completed repairs, I discovered that they had inadvertently left a wrench very high on a ledge of one of the chimpanzees’ enclosures. Unfortunately, I found this out when I greeted Washoe and saw that she was busily testing the bolts along the enclosure’s fencing with the wrench. Luckily, she really wasn’t getting far with it, but I certainly didn’t want to explore the limits of her mechanical skills. I needed to get the wrench back, but how? I decided to try for a trade. Though the chimpanzees have a far healthier diet than me most of the time, they enjoy treats every once in a great while. Coffee is a favored treat beverage, so I poured some coffee with creamer and excitedly presented it to Washoe and Tatu, who also happened to be nearby. I signed to ask for the wrench back. Tatu seemed eager to take me up on the offer, but Washoe looked unimpressed as she continued to clutch the wrench. It was time to up the ante. Washoe loved soda, so I poured some of that instead. This piqued her interest, so I asked for the wrench again. She gladly handed it over and enjoyed the soda along with Tatu. Washoe knew that the first rule of negotiating is never to accept a first offer. It paid off.

She was brainy and creative. When caregivers at CHCI clean the chimpanzees’ enclosures, they use hot water from hoses to spray down and rinse areas. While caregivers clean an area the chimpanzees are no longer using, the chimpanzees sometimes come to the fence of an adjacent room and ask for drinks from the hose. Washoe often liked to sip her hot water from a cup as she watched us clean. Sometimes she also made herself a day nest and reclined luxuriously as warm steam poured into her enclosure through the fence, creating her own personal sauna area. On this particular day, she looked around, but no cups were nearby. Instead, she picked up the hollow rubber head of a baby doll. (Though Washoe liked children, baby dolls didn’t often fare well in her care.) She inverted the doll head and held it up to the fence so I could aim the stream of hot hose water into the head. Though I probably never would have considered the functionality of this object as a container, Washoe quickly solved the problem and found herself a perfectly good cup.

Though Washoe was a very unique individual, she was in other respects an ordinary chimpanzee. That is, she was not a brilliant exception among chimpanzees. The other members of her chimpanzee family also acquired ASL signs. Though her upbringing was distinct, she shares a great deal with the chimpanzees I study here in Uganda. Chimpanzees here share similar sentience, a similar reliance upon gestural communication (while using a somewhat different set of gestures), and a similar capacity for joy and pain. Thus, while Washoe is a great ambassador for chimpanzees, she should not be placed on a pedestal as uniquely gifted among her kind. She is just one chimpanzee of many taken from her African forest home and transferred to an utterly foreign place to lead an altogether different life than the one she would have otherwise had. Thankfully, it’s no longer legal to capture chimpanzees from Africa and transport them abroad. It still happens occasionally, but realistically, threats like bushmeat hunting and habitat loss pose much greater risks to free-living chimpanzees today. Though I miss Washoe now and always, I’ll always be grateful for the many lessons she taught me about herself and her kin which, after all, includes us humans too.

*The members of Washoe’s chimpanzee family at the Chimpanzee and Human Communication Institute are equally spectacular beings, with their own fascinating life histories. This “family” is not biologically related, but has been a stable family unit for over 30 years. Read more about the others—Moja, Tatu, Dar, and Loulis—at www.friendsofwashoe.org.

Learn more about Washoe and her family:

• The book I highly recommend: Next of Kin, by Roger Fouts with Stephen Tukel Mills
• The website with lots more info: Friends of Washoe
• The research publications

This post was originally published at Scientific American. 

A trusted Ugandan colleague called one afternoon to share the news that he had found someone whom I might hire as a field assistant. Jack and I met with our colleague and the prospective hire, Nick, an hour later in town. Nick is a young forestry college graduate with knowledge of local trees and an eagerness that was immediately evident. I offered him the job and our work began soon after.

Upon venturing into the field a couple days later, we found our first and most familiar sign of chimpanzee presence: nests. For the most part, chimpanzees build a new nest each night. These large, leafy beds are constructed by bending branches into a rounded, cushiony shape. The interwoven leaves and branches create a kind of mattress high in the trees. Nest construction is a skill that takes some time to learn, so young chimpanzees sleep in their mothers’ nests until they are old enough to reliably build their own. Nests of the same age are often found together, evidence that a party, or small group, of chimpanzees slept near each other.

A chimpanzee nest. Photo: Maureen McCarthy.

The view from inside a chimpanzee nest. Photo: Jack Lester.

Finding nests is vital to my research project. Nests provide crucial information regarding where the chimpanzees have been spending their time. This is important because the chimpanzees I study are unhabituated, meaning they are not accustomed to researchers following them closely. Unhabituated chimpanzees typically flee when people come near, as is the case with my study subjects. For this reason, we must rely primarily on indirect evidence rather than direct observations to better understand their behavior patterns. Luckily, the chimpanzees leave ample clues for us. After we find their nests, we often encounter a second critical clue: their dung. Chimpanzee dung can provide a wealth of information. It can provide insights into what the chimpanzees are eating, how long ago they’ve been in a certain area, and much more. My study relies on these little treasure troves to provide chimpanzee DNA. I will later analyze the DNA to answer various questions about the genetics and behavior of these chimpanzees.

I won’t lie. Collecting chimpanzee dung doesn’t quite fit the romantic, Jane Goodall-in-khaki-shorts image of primatology research that I held some years ago. I remember when my first primate behavior professor, Michele Goldsmith, described studying mountain gorillas in Uganda. As she explained it, seeing gorillas was all well and good, but finding their dung was the real thrill. Like me, she relied on dung samples to provide critical data for her research. Though I knew she was joking a bit, I also couldn’t imagine how finding dung could be so exciting. Now I get it. The highlight of my day often comes when I stumble upon a fresh pile of chimpanzee dung. Nick listens patiently as I excitedly wax on about the intricacies of poo and demonstrate proper collection technique, then sift through remnants just to see what fascinating discoveries might await us inside our gooey gift from the chimpanzees. I’m certain he must think we’re a bit crazy, especially because direct observations of the chimpanzees have been scarce so far.

Scarce–that is–until yesterday, when we were fortunate enough to have both ample chimpanzee observations and fresh samples to collect. Though we maintained a long distance from the chimpanzees so as not to disturb them, we watched them groom and feed for some time before entering an area they had passed through to see what they left behind. In the process, we found several nests, dung samples, and feeding sites. Data-rich days like these make up for the occasional long days of walking with little or no evidence that chimpanzees aren’t just some figment of our imaginations. For now, I’ll remain satisfied that they exist while continuing to wonder about the many unresolved mysteries of their fascinating lives in these small islands of forest.

Chimpanzee mother and infant. Photo: Jack Lester.

This post was originally published at Scientific American.

The first days of a research trip follow a characteristic pattern among the field researchers I know. The story goes something like this. Step 1: Arrive in capital city. Step 2: Run necessary errands as quickly as possible. Step 3: Leave capital city to get to field site. Step 4: Avoid capital city like the plague thereafter for as long as possible. (Note: Steps 2 and 3 are often accompanied by some amount of frustration. Do not expect things to go as planned.) This pattern is typical because most field researchers enjoy being, well, in the field. The hassles of city life are a necessary obstacle to getting to the fun stuff.

Traffic in Kampala. Photo: Maureen McCarthy.

So went our week. We spent most of it in Kampala, where we made necessary vehicle repairs, purchased supplies, and visited government offices. Chief among our list of vehicle repairs was finding a permanent replacement for a temporary window that had been glued onto Lucy (as my Land Cruiser is known). I got Lucy during my previous trip to Uganda last year, and she’s been in the care of friends during the intervening months since I left. We found her in good condition upon return, with the exception of this new window, which served to temporarily replace its shattered predecessor. We learned that the old window had been broken by a rock sent flying as someone cut grass nearby. Replacing the glass with a more permanent fix required meeting the automotive glass technicians in downtown Kampala. We met them on the street, where they emerged from a bustling, crowded sidewalk with the new window in hand. They proceeded to extract the old replacement window and install the new one right there on the sidewalk as passersby looked on. In about a half hour, they had completed the job admirably.

A technician removes Lucy’s temporary window. Photo: Maureen McCarthy.

By the time we had completed this and various other tasks, we were ready to get out of the city. Our drive back to our home base of Hoima was a welcome change of pace from Kampala’s bustling crowds. As we made our way through the lush rolling hills and villages, we were at times awestruck by Uganda’s beauty.

Photo: Jack Lester.

Photo: Jack Lester.

Photo: Jack Lester.

Back in Hoima, we’ve been settling in for a few days. We’ve ordered furniture from a local carpenter, who will make some modest furnishings for our house. Before we can fully move in, though, we had to evict some unwanted tenants. Jack discovered an aggressive spider in the garage. Upon closer inspection, he found that it resembled a black widow spider. It actually turned out to be a close relative, the brown widow spider, Latrodectus geometricus.

A brown widow spider in the garage. Photo: Jack Lester.

Brown widow spiders, as we learned, carry toxic venom like their cousin the black widow spider, but typically inject less venom per bite. We found two adult females with several egg sacs in the garage. After removing them, we decided to inspect our neighbor Matt’s garage. Two more females, several more egg sacs. Now we’re on alert! If you think you’re safe from these tiny terrors as long as you avoid East Africa, think again. They are increasingly common throughout much of the southern U.S., including California. I can’t say I’ve ever had them as such close neighbors before, though.

Brown widow spider egg sacs. Photo: Maureen McCarthy.

When we’re not evicting spiders, I’m also searching for a new field assistant. My prior field assistant, Henry, was great at his job but found other employment since my last trip here and can no longer continue working for me. I’m very pleased that he found a job while I was away, but he will be sorely missed. The search is on for a suitable replacement who can fill Henry’s figuratively big but literally small shoes. (He is a very small man, you see.) I hope to share good field assistant news soon. In the meantime, keep an eye out for spiders. I know I will.

This post was originally published at Scientific American. 

After weeks spent packing, moving from our apartment, and traveling, my partner Jack and I have finally arrived in Uganda. Though it will still take some time to get settled into the place we’ll call home for the next year, a currently empty house in western Uganda will soon begin to feel familiar. The notion of a nice place to come home to at the end of a long day in the field sounds very appealing.

We humans are not the only ones to recognize home. For chimpanzees, home typically consists of an area of habitat called their home range, often measured as the area a chimpanzee community travels over a year. Home ranges vary in size across chimpanzee communities, ranging from under 10 km² to over 50 km². In eastern chimpanzees—the subspecies I study—females often favor certain parts of their community’s home range. This favored region, called a core area, is where a particular female will spend much of her time feeding and nesting, often with her offspring. Male chimpanzees, who remain in the community in which they were born through adulthood, come to know their mother’s core area from a young age. Murray and colleagues found that males at Gombe National Park, Tanzania continue to visit and forage in their mothers’ core areas even into adulthood, especially when solitary.  This suggests that particularly when food is scarce, these males reduce feeding competition and increase foraging efficiency by heading for the old familiar areas they know best.

What is home like for chimpanzees whose habitat is rapidly being altered, however? What space does a female carve out for herself and her offspring when she can scarcely escape the sound of chainsaws? What must it be like for an adult male to try to stop by for a bite to eat at an old favorite tree from childhood, only to find out the tree has been logged? Because habitat loss is a staggering issue for chimpanzees here in Uganda as well as elsewhere, these experiences must be very common. A recent article by numerous great ape researchers attests to the rapid rate of habitat loss for our ape cousins. Every day, chainsaws send favored nesting trees crashing to the ground, humans carve new and altered paths through fragile forests, and pit saws slice fruiting trees into timber planks.

A male chimpanzee crosses a road that bisects his forest home. Photo: Maureen McCarthy.

For the elders in the chimpanzee communities I study, I wonder how they perceive the changes over the course of their lives, which can last up to 50 years or more. Are they fearful when they awake to the sound of loggers nearby? Do they feel angry about the deterioration of their forest home? Unfortunately, we can never be certain how they feel. However, Dr. Matthew McLennan, my colleague and soon-to-be next-door neighbor in Uganda, co-authored a fascinating article with Dr. Catherine Hill on chimpanzee responses to researchers in Uganda. Their findings suggest these chimpanzees use numerous strategies—including aggression—for dealing with a habitat increasingly disturbed by human presence.

For the youngest chimpanzees, I wonder what the future holds. They have never known life in an undisturbed forest. Will they masterfully adapt to life in a mosaic habitat among their human neighbors? Or will the environmental pressures prove to be too much to handle? Though my research will hopefully help fill in some pieces of the puzzle, much uncertainty remains for our chimpanzee cousins who rely on something called “home” just as we do.

This post was originally published at Scientific American.