Gorilla

 Gorilla tracking in Uganda, Rwanda and Congo

Recent DNA evidence has reclassified gorillas, previously considered one species (Gorilla gorilla) with three subspecies, into two distinct species: Gorilla beringei (eastern populations) and Gorilla gorilla (western populations). The eastern mountain gorillas now fall under the classification Gorilla beringei beringei, with two populations located in the Virunga Volcanoes and Bwindi Impenetrable National Park. Despite being depicted as aggressive, gorillas are actually shy, peaceful vegetarians. However, they face significant extinction risks due to habitat loss.

   

ANATOMY
Gorillas have long arms, a short, bulky body, and a wide chest. They primarily walk on all fours but can walk upright for brief periods, such as when beating their chests, during encounters, or while carrying food or infants. Bipedal movement is rare in gorillas.

 

Hair and Skin:
Gorillas have black hair covering most of their body, excluding their fingers, palms, face, armpits, and the bottoms of their feet.

The Head:
Gorillas possess a large head characterized by a prominent forehead and a sagittal crest, which is more pronounced in males. They have small, dark-brown eyes, tiny ears, and no tail. Adult gorillas have 32 teeth, including large molars for chewing and prominent canines for biting, particularly developed in males. Additionally, each gorilla has a unique nose print, similar to human fingerprints.

Senses:
Gorillas possess senses akin to humans, featuring hearing, sight (slightly nearsighted with color vision), smell, taste, and touch.

Hands and Feet:
Gorillas have five fingers with an opposable thumb on their hands and five toes, including an opposable big toe, on their feet, allowing them to grasp objects with both hands and feet.

Gorilla foot and hand

     

SIZE
Male gorillas are significantly larger than females, often weighing nearly twice as much. Adult males, referred to as silverbacks, acquire a distinctive saddle-shaped patch of silver hair on their backs after reaching approximately 12 years of age.

 

DIET
Gorillas are mostly herbivores, foraging primarily for leaves, fruit, seeds, bark, bulbs, shoots, and flowers during the day. They consume parts from over 200 plant species and occasionally eat termites and ants. Typically, they do not drink water, relying on moisture from their food, with an average adult male consuming about 50 pounds daily.

INTELLIGENCE AND LANGUAGE
Gorillas exhibit high intelligence and are capable of learning complex tasks.

Language:
Some gorillas have learned sign language from humans, enabling them to form simple sentences and communicate.

Tools:
Gorillas are not observed using tools in the wild, but they can learn to use them in captivity.

BEHAVIOR AND SOCIAL HABITS

Bands of Gorillas:
Gorillas are shy, social animals that are active during the day (they are diurnal). They live in small groups (or bands) of 6-7 individuals, including one silverback (adult male), a few females, and their young. When the young mature, they go off and join or form another band.

Grooming:
Grooming one another (cleaning the hair of another gorilla) is a major occupation among gorillas in a band. Female gorillas groom their offspring, one another, and the silverback; the silverback does not groom others.

Sleeping Nests:
Each evening, gorillas construct a “nest” for the night in which they will curl up and sleep. These bowl-shaped nests are made out of leaves and other plant material. Nests are only shared by a mother and her nursing offspring. Scientists who study gorillas can easily estimate a local gorilla population by counting the number of “nests.”

Aggression:
Gorillas are generally not aggressive; they typically make noise when disturbed but rarely confront intruders.

COMMUNICATION AND VOCALIZATION

Gorillas are generally quiet yet communicate with various sounds and gestures, utilizing at least 25 vocalizations like grunts and roars. Their gestures include chest-beating and high-pitched barks. This communication aids in teaching younger gorillas survival skills and discussing topics such as food, social interactions, distress, and mating.

LOCOMOTION:
Gorillas primarily use a knuckle-walking gait, relying on both their legs and long arms while keeping their fingers rolled into their hands. They infrequently walk on their legs alone and can climb trees, though they do not do so often. Additionally, gorillas are not capable of swimming.

LIFE SPAN
Gorillas have a lifespan of approximately 50 years in captivity, compared to about 35 years in the wild, indicating that they tend to live longer in controlled environments.

HABITAT
Gorillas are mostly terrestrial, though their ancestors lived in trees. They inhabit tropical rainforests, including forest edges, clearings, wet lowland forests, swamps, and abandoned fields.

DISTRIBUTION:
The different subspecies of gorillas live in different parts of western Africa.

• Subspecies . gorilla, the western lowland gorilla, is found at low altitudes in Cameroon, Central African Republic, Gabon, Congo, and Equatorial Guinea.

• Subspecies g. Graueri, the eastern lowland gorilla, is found in eastern Zaire.

• Subspecies g. Beringei, the mountain gorilla, is found at high altitudes (from 5,400 to 12,440 feet or 1,650 to 3,800 m) in Zaire, Rwanda, and Uganda.

REPRODUCTION AND BABY GORILLAS

Gorillas reach maturity and can reproduce at 10-12 years old. Females are pregnant for 8 to 9.5 months, typically having about three offspring in their lifetime. Newborns weigh 3-4 pounds and are nurtured carefully by their mothers. They learn to crawl by 2 months and can walk before 9 months. At 4 months, they can cling to their mother’s fur. For the first 2.5 years, they consume mother’s milk, after which they build their own sleeping nests from vegetation. Young gorillas remain with their mothers for 3-4 years, while adult male silverbacks may care for orphaned young gorillas.

 

POPULATION COUNTS
Gorilla populations are declining and at risk of extinction, with an estimated 50,000 remaining in the wild in Africa. The majority are western lowland gorillas, while mountain gorillas number about 600 and eastern lowland gorillas approximately 2,500. Mountain gorillas are critically endangered.

THE EVOLUTION OF GORILLAS:
The earliest primates appeared approximately 70 million years ago. Greater apes, including gorillas, chimpanzees, bonobos, and orangutans, diverged from lesser apes around 20 million years ago, with chimpanzees being the genetic closest relatives to gorillas and to humans.