The Battle of the Great Apes: Gorillas versus Chimpanzees

When I learned I was going to do an internship in Uganda for six months, I immediately started researching the country and its highlights. Naturally, one of the first things that came up was gorilla tracking. I remember opening the page, scrolling through it and getting excited, until I saw the price tag and realised my student budget would never allow it. I continued scrolling, a bit disappointed, but still thrilled by the many activities this country had to offer. Then I found the possibility to go chimpanzee tracking. This program was more affordable, so I decided to consider it. 

Now a couple of months later, I have been blessed to experience both. One little perk of this pandemic is that all of the national parks in Uganda offer serious reductions. This includes Mgahinga Gorilla National Park and Kibale National Park where you can meet mountain gorillas and chimpanzees, respectively. Chimpanzees — together with bonobos — take pride as our closest living relatives with 99% of shared DNA, while the gorillas follow with 98%. If you think a primate is a primate and they are more or less the same, you are very wrong. That tiny percentage of unshared DNA makes for a world of difference between humans and primates, but also between chimpanzees and gorillas. In fact, scientists say that chimpanzees are more closely related to humans than they are to gorillas! So don’t call them by the same name. Would you like it if someone called you a gorilla? 

Let’s start with what they have in common. It’s not good news, but it is one of the reasons why it is such an extraordinary experience to be able to see them in the wild: both of them are endangered. Poaching, diseases, civil war, and habitat destruction plague both species. The chimpanzee population is currently estimated at around 170,000 to 300,000, while the mountain gorillas — a subspecies of the eastern gorilla — counts just above 1,000. Fortunately, despite years of unrest in the region where mountain gorillas live, conservation efforts there have been successful. The population of mountain gorillas has continued to increase leading to their being downlisted from ‘critically endangered’ to ‘endangered’ in November 2018.

Now let’s get into their differences. 

Size of Gorillas versus Chimps

When we finally reached the bushy area in Mgahinga where the gorillas had been resting that day, I felt a bit discouraged. It had started drizzling, mildly but persistently, and the gorillas were taking shelter under some of the lower trees and bushes. All I saw was this big, black hairy lump sticking out of the high grass, and I couldn’t figure out what exactly I was looking at. Was it part of a back or maybe the buttocks? It was only when the rangers reassured us that we could go a little closer that I suddenly realised this big chunk of gorilla was actually its head! It was the size of a giant watermelon.

The head of a gorilla is massive, with a bulging forehead overhanging the eyes and a bony sagittal crest on top that supports the large muscles needed to grind coarse vegetation. Adult male mountain gorillas may weigh up to 220 kg (484 lbs), while females weigh about 97.7 kg (215 lbs). That makes them two to three times larger than chimpanzees and therefore, a little bit more impressive when seen close up. 

Peacefulness of Gorillas, Violence of Chimps

When it comes to making a choice between seeing one of the two species, some people would opt for the chimpanzees because gorillas scare them (hey, mom!). While mountain gorillas are very strong, and you would definitely not stand a chance if one of them would want to fight you, gorillas are actually very peaceful animals that rarely start trouble. Gorillas are highly empathetic. In 1996, a three-year-old boy fell into the gorilla enclosure at the Brookfield Zoo outside of Chicago and a female gorilla picked him up and cradled him, then took him to a door so her handlers could take him. 

Gorillas spend the majority of their time resting, relaxing, and interacting with each other. Despite their threatening looks and large size, they are remarkably sedate. This behaviour makes them great models for picture taking or to watch with the naked eye. On the contrary, chimpanzees might not be that strong, but they are a violent species that easily start trouble and can gang up against rivals in fights to the death. Forest clearing in Uganda has forced hungry chimps to raid villagers’ crops, sometimes leading to attacks on humans. 

Both gorilla and chimpanzee tracking are absolutely safe, as these primates are habituated to humans. The presence of long-term research teams has made them less shy and easier to view, without compromising or interfering with their natural behaviour. That being said, the chimps will be jumping around in the trees above your head. They will be squeaking loudly and might even jump out of a tree right in front of you. I must confess that, while I am not a panicky person, even I had to suppress a shriek once in a while. When some of the chimps would start to get riled up, our guide would assure us to keep calm and not start running. Although very entertaining, for someone who scares easily, chimpanzee tracking might not be ideal. 

Social Skills of Gorillas and Chimps

Both of these primates are social animals. However, chimpanzees are even more so than gorillas, living in communities of over 100 individuals. Gorillas live in smaller groups of not more than 40. A gorilla’s family life is centred around the silverback, the dominant adult male who is recognised by the swath of silver hair on his back that comes with maturity. What is extraordinary about Mgahinga National Park is that the habituated Nyakagezi gorilla family has no less than three silverbacks. 

The dominant silverback is Mark, who took over leadership from his father Bugingo, and is recognisable by a brownish strand of hair on his forehead. Mark got my attention when he was seated grumpily in the middle of a field of grass with his arms crossed around his middle to protect his hairless chest from the rain. I had been staring at his mighty appearance for at least 15 minutes when all of a sudden, he looked up and our eyes locked. We looked into each other’s eyes for at least 30 seconds, and I felt this immense connection, as if he was as interested in me as I was in him. 

The silverback is the centre of the troop. He makes all of the decisions, mediates conflicts, determines the movements of the group, leads the others to feeding sites, and takes responsibility for the safety and well-being of the troop. We noticed this in the way that Mark talked to his family members, alerting them when we arrived and when we left.

While chimps don’t have family members that stand out as much as the silverback, the sheer magnitude of a group of chimps makes it an exhilarating experience. Kibale Forest is like a playground for chimps and has the highest concentration of them in East Africa.

The main difference between gorilla tracking and chimpanzee tracking is that watching the chimps is more exciting. With the gorillas, you know in advance which family you are going to see, how many silverbacks and infants there are, what their names are, etc. With the chimps, there are hundreds of them, and you see multiple families. They live in communities, so you might come across a group of kids, then two will leave and another eight individuals will join. There is always a fight breaking out over who the alpha male is, and who gets the female in estrous (ready to mate). The energetic nature of the chimps makes it harder to photograph them, but they force you to stay alert, which can be a good thing. Luckily for me, after about 40 minutes of active female pursuit, most of the males got tired and came down to rest. 

Habitats of Gorillas and Chimps

Tracking gorillas in Mgahinga National Park isn’t your average walk in the park. We left our idyllic Gahiza Island Retreat, located on a small island in Lake Mutanda, at the break of dawn. By the time we arrived at the starting point of our trek, it was already past 9:00. We first had to drive down a long dirt road with more potholes than you can count, and then climb the last part to the office that can only be reached on foot. 

Both mountain gorillas and chimpanzees live in forested areas. However, as the name suggests, the mountain gorillas live in the mountains at elevations between 2,400 and 3,900 metres (8,000 to 13,000 feet). Their thicker fur helps them to survive in a habitat where temperatures can drop below freezing. This has two important consequences for trackers. First, you’ll have to hike upwards in jungle-like vegetation which can be challenging for a lot of people. Second, it actually gets cold! A lot of people have trouble believing that it ever gets cold on the African continent, but you better believe it does! When you are hiking, you will feel the heat, but when you’re quietly seated watching the gorillas, you will regret it if you didn’t bring a jacket. 

When we arrived at the office, most of us were already breathing heavily. While we were filling out the forms, it started raining, and I suddenly knew that my light sneakers wouldn’t do. Luckily, they had walking shoes in all forms and sizes to help out unprepared visitors like myself. Then our quest started. First we walked on narrow pathways but after a while we had to abandon those, because gorillas tend to wander off the beaten track. The scenery changed about every half hour, from woodland to bamboo, making the walk worthy in itself. We climbed through dense bushes and then through open grass fields. We reached the Nyakagezi family after about two hours. Tired, but satisfied, we crouched down to admire the presence of these mighty creatures. 

In conclusion, getting the chance to see either one of these primates in their natural habitats is an amazing experience. However, if you have to choose, I hope this article can help you make an informed decision. In the meanwhile, reductions are still going on, so the sooner you can get here the better! 

featured photo by Marcus Westberg, others by the author