Differences and Similarities Between Gorillas and Chimpanzees

Anyone planning to observe wild primates in Africa will eventually wonder what differences they will encounter between gorillas and chimpanzees. This curiosity is natural, especially for travelers whose safaris include both species. Many people confuse gorillas with chimpanzees, yet they are quite distinct in behavior, appearance, and lifestyle.

Both gorillas and chimpanzees belong to the Hominidae family. They are classified as great apes, along with humans, orangutans, and bonobos. Although they both thrive in the equatorial belt of Africa, their habitats, ranges, and population densities differ significantly.

Evolution and Classification

To begin with, gorillas belong to the genus Gorilla, which is divided into two species: the western gorilla (Gorilla gorilla) and the eastern gorilla (Gorilla beringei). Each species is further split into subspecies:

• Western Gorilla: Western Lowland Gorilla (Gorilla gorilla gorilla) and Cross River Gorilla (Gorilla gorilla diehli).
• Eastern Gorilla: Mountain Gorilla (Gorilla beringei beringei) and Eastern Lowland Gorilla (Gorilla beringei graueri).

Mountain gorillas live at high altitudes in the Virunga Massif, while western lowland gorillas inhabit Cameroon, Gabon, and the Republic of Congo. By contrast, the Cross River gorilla survives in Nigeria and Cameroon, and the eastern lowland gorilla inhabits the Democratic Republic of Congo.

Chimpanzees, on the other hand, belong to the genus Pan. They occur in 21 African countries, with strong populations in Guinea, Tanzania, and Uganda. The Pan genus includes two species: the common chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus). The common chimpanzee is divided into four subspecies: central, western, eastern, and Nigeria-Cameroon.

Moreover, genetic research shows that humans share a closer relationship with chimpanzees than with gorillas. According to the Human Genome Project (2005), humans and chimpanzees share 98.7% of their DNA.

Facial Features and Expressions

When comparing appearances, gorillas typically have deep-set eyes, large nostrils, and a wide, flat muzzle. Their facial expressions remain consistent and calm, giving them an air of composure. Strong eye contact, though intense, rarely shifts dramatically.

Chimpanzees, however, are much more expressive. Their ears, lips, and eyebrows move frequently, and their faces constantly shift to reflect emotions. While they are playful, their moods can suddenly shift into aggression, leading to loud screams or dramatic outbursts.

Body Size and Movement

Another clear difference is size. Mature silverback gorillas weigh between 140 and 190 kilograms, while females average 100 kilograms. Their massive strength lies in their upper bodies, supported by broad chests, strong shoulders, and thick forearms.

Chimpanzees are smaller, yet incredibly powerful. A male weighs only 40 to 60 kilograms, but his muscle density makes him three times stronger than a human of the same weight. Their long arms and limbs allow them to swing through trees with unmatched agility, unlike gorillas, who spend most of their time on the ground.

In terms of movement, gorillas are deliberate and slow, particularly on steep trails. Juveniles often climb trees to play, but adults do so only for fruit or rest. By contrast, chimpanzees spend most of their time in trees, moving swiftly from branch to branch before coming down to forage.

Gender Differences

The sexual dimorphism between male and female gorillas is striking. Male gorillas, especially silverbacks, have broader chests, larger jaw muscles, and the distinctive silver streak of hair on their backs. They dominate and protect their groups with authority.

On the other hand, male and female chimpanzees appear more similar. Although males dominate, their authority is unstable. Females form alliances and often mate with multiple males. Leadership changes frequently, making their social life more volatile than that of gorillas.

Social Structure and Leadership

Social organization further highlights the differences. Gorillas live in cohesive family units led by a dominant silverback. He decides when to feed, rest, or move and provides stability and protection for his family.

Chimpanzee communities, however, are far less stable. They split into subgroups for days and reunite later. Leadership depends on alliances and politics rather than brute strength alone. The dominant male must constantly negotiate, groom, and strategize to maintain power.

Aging in Gorillas and Chimpanzees

As gorillas age, they develop grey hair around their face and arms, move more slowly, and show stiffness in their joints. Older silverbacks become vulnerable to takeover attempts by younger rivals.

Chimpanzees age differently. Their faces darken or become patchier, and while they may lose dominance, older males can maintain influence by forming strategic alliances with younger leaders.

Intelligence and Tool Use

When it comes to intelligence, chimpanzees stand out. They use tools frequently, fishing termites with sticks, cracking nuts with stones, and collecting water with chewed leaf sponges. They even teach these skills to younger chimps, showcasing cultural learning.

Gorillas, on the other hand, use tools less often, largely because they live in food-rich environments. Nevertheless, some western lowland gorillas have been observed using sticks to test swamp depth or placing logs across marshes to cross.

Communication Styles

Communication also sets them apart. Gorillas rely on hoots, grunts, chest-beating, and body language. A silverback may use low rumbles to guide or calm his group.

Chimpanzees, however, communicate with a wider range of signals. They use facial expressions, hand gestures, grooming, and loud vocalizations such as screams and hoots. Grooming not only ensures hygiene but also strengthens alliances within the group.

Emotions and Memory

Both species display complex emotions and strong memory. Gorillas show compassion by staying close to distressed members or visiting sites where relatives died.

Chimpanzees also demonstrate empathy but excel in strategy and memory. They anticipate outcomes in group politics and design tactics to maintain or challenge dominance.

Conservation Concerns

Unfortunately, both gorillas and chimpanzees face serious threats.

• Gorillas:
  • About 250,000 western lowland gorillas remain, but poaching, mining, and logging threaten them.
  • Only about 1,000 mountain gorillas survive in Uganda, Rwanda, and the DRC. These are closely monitored and protected through tourism.
  • Eastern lowland gorillas number around 7,500, while fewer than 300 Cross River gorillas remain.
• Chimpanzees:
  Although still widespread, chimpanzees are endangered due to habitat loss, poaching, pet trade, and diseases. Their proximity to human settlements makes them especially vulnerable.

Tourism, when managed responsibly, plays a vital role in conserving both species. However, there is always the risk of human diseases spreading to primates, which could have devastating consequences.

Final Thoughts

In conclusion, gorillas and chimpanzees share similarities as great apes, yet they differ profoundly in lifestyle and behavior. Gorillas embody calm strength and family stability, while chimpanzees represent intelligence, adaptability, and political complexity.

Observing both species in the wild is a life-changing experience, offering not only a glimpse into their fascinating lives but also a reflection of our own evolutionary story.