ALL ABOUT GORILLAS
Gorillas are the largest species of primates alive today. They are ground-dwelling, predominantly herbivorous, and although they are frequently portrayed as aggressive, dangerous killers, they are in reality shy, peaceful vegetarians. Furthermore, because of massive loss of habitat, these majestic primates are now at huge risk of extinction!
The Gorillas natural habitat covers the tropical and subtropical forests of Africa. Although their range covers only a small percentage of Africa, gorillas cover a wide range of elevations. The mountain gorilla inhabits the Albertine Rift montane cloud forests of the Virunga Volcanoes, ranging in altitude from 7,200–14,100 ft. Lowland Gorillas live in dense forests and lowland swamps and marshes as low as sea level, with western lowland gorillas living in Central West African countries and eastern lowland gorillas living in the Democratic Republic of the Congo near its border with Rwanda.
Silverbacks are typically more than 12 years of age and named for the distinctive patch of silver hair on his back, which comes with maturity. A silverback gorilla has large canine teeth that also come with maturity.
Both males and females tend to emigrate from their natal groups. Dispersal from natal troops is more common in females than males for mountain gorillas. Female mountain gorillas and western lowland gorillas also commonly transfer to a second new group.
In a single male group, when the silverback dies, the females and their offspring disperse and find a new troop. Without a silverback to protect them, the infants will likely fall victim to infanticide, and searching out and joining a new group is likely to be a tactic against this. However, while gorilla troops usually disband after the silverback dies, female eastern lowlands gorillas and their offspring have been recorded staying together until a new silverback transfers into the group. This likely serves to decrease chance of being attacked by leopards. Although very rare, all male troops have also been recorded.
Relationships between females may vary. Maternally related females in a troop associate closely and tend to have friendly interactions. Otherwise, females usually have little friendly interactions and commonly act aggressive towards each other. Aggressive interactions between females tend to be centered around social access to males with males intervening in fights between females. Male gorillas have weak social bonds, particularly in multi-male groups with apparent dominance hierarchies and strong competition for mates. However, males in all-male groups tend to have friendly interactions and socialize through play, grooming and close proximity, and occasionally they even engage in homosexual interactions.
How do Gorillas Communicate?
Deep, rumbling belches suggest contentment and are heard frequently during feeding and resting periods. They are the most common form of intragroup communication. Severe aggression is rare in stable groups, but when two mountain gorilla groups meet, the two silverbacks can sometimes engage in a fight to the death, using their canines to cause deep, gaping injuries. The entire sequence has nine steps:
1. Progressively quickening hooting.
2. symbolic feeding.
3. Standing upright.
4. Throwing vegetation.
5. Chest-beating with cupped hands.
6. A single leg kick.
7. Sideways running, two-legged to four-legged.
8. Slapping and tearing vegetation.
9. thumping the ground with palms to end display.
Tool use in Gorillas
In September 2005, a two and a half year old gorilla in the Republic of Congo was discovered using rocks to smash open palm nuts inside a game sanctuary. While this was the first such observation for a gorilla, over 40 years previously chimpanzees had been seen using tools in the wild, famously 'fishing' for termites.
Great apes are endowed with a semi-precision grip, and certainly have been able to use both simple tools and even weapons, by improvising a club from a convenient fallen branch.
For related articles click onto the following links:
ALL ABOUT GORILLAS
WHAT DO GORILLAS EAT?
WHAT IS A GORILLA?