Gorilla

Largest primate

Gorillas are the largest living primates — adult silverback males weighing up to 200 kg. The size doesn’t translate to aggression: gorillas are largely gentle vegetarians, eating leaves, fruit, bamboo shoots, and occasional ants. Despite the chest-beating displays that seem aggressive, gorilla societies are mostly peaceful within and between groups.

A silverback’s chest-beating display advertises strength to potential rivals or threats — an alternative to actual combat. Most “aggressive” gorilla encounters with humans end without contact.

Four subspecies

Gorillas are now recognized as two species and four subspecies, all critically threatened:

• Western lowland gorilla (G. g. gorilla) — most numerous, ~100,000 remaining in Cameroon, Republic of Congo, etc.
• Cross River gorilla (G. g. diehli) — fewer than 300 remaining, restricted to Nigeria-Cameroon border.
• Eastern lowland (Grauer’s) gorilla (G. b. graueri) — ~3,800 remaining in DRC.
• Mountain gorilla (G. b. beringei) — ~1,000 in Virunga and Bwindi national parks. Slowly recovering due to intensive conservation; population doubled since 2010.

Mountain gorilla recovery

Mountain gorillas are the only great ape population that has grown in recent decades. From ~250 in the 1980s to over 1,000 today, the recovery is attributed to:

• Intensive park ranger protection
• Sustainable gorilla tourism (highly regulated, expensive permits)
• Veterinary intervention for sick or injured individuals
• Community-based conservation that benefits local people

Dian Fossey’s research at Karisoke (1967–1985) raised global awareness; her assassination in 1985 cemented mountain gorillas as a conservation icon.

Disease shared with humans

Gorillas are vulnerable to human diseases because of our genetic similarity. A common cold or respiratory infection passed from a human tourist can be fatal to a gorilla. Tourism protocols now require:

• Distance from gorillas (7+ meters)
• Mask-wearing during encounters
• Pre-visit health screening
• Limits on group size and visit duration

These rules have become more strict during COVID-19.