Hello all friends,
Gorillas are ground-dwelling, predominantly herbivorous
great apes that inhabit the tropical forests of central Sub-Saharan Africa.
The genus Gorilla is divided into two species: the eastern gorillas
and the western gorillas.
They are the largest living primates. Let's discover this animal.
The DNA of gorillas is highly similar to that of humans,
from 95 to 99% depending on what is included,
and they are the next closest living relatives to humans after chimpanzees and bonobos.
Gorillas stay in families just like humans. Families have up to 20 members.
They usually walk on four limbs and only use their feet for a short while.
They don’t have tails.
They build a sleeping nest every evening and occasionally one for the midday nap.
Physical characteristic
Wild male gorillas weigh 136 to 227 kg, while adult females weigh 68–113 kg.
Adult males are 1.4 to 1.8 m tall, with an arm span that stretches from 2.3 to 2.6 m.
Female gorillas are shorter at 1.25 to 1.5 m, with smaller arm spans.
The eastern gorilla is more darkly coloured than the western gorilla,
with the mountain gorilla being the darkest of all.
The mountain gorilla also has the thickest hair.
The western lowland gorilla can be brown or greyish with a reddish forehead.
In addition, gorillas that live in lowland forest are more slender
and agile than the more bulky mountain gorillas.
The eastern gorilla also has a longer face and broader chest than the western gorilla.
Like humans, gorillas have individual fingerprints.
Their eye colour is dark brown, framed by a black ring around the iris.
Gorilla facial structure is described as mandibular prognathism,
that is, the mandible protrudes farther out than the maxilla.
A gorilla's lifespan is normally between 35 and 40 years,
although zoo gorillas may live for 50 years or more.
Colo, a female western gorilla at the Columbus Zoo and Aquarium,
was the oldest known gorilla at 60 years of age when she died on 17 January 2017.
Distribution and habitat
Gorillas have a patchy distribution.
The range of the two species is separated by the Congo River and its tributaries.
The western gorilla lives in west central Africa,
while the eastern gorilla lives in east central Africa.
Between the species, and even within the species,
gorillas live in a variety of habitats and elevations.
Gorilla habitat ranges from montane forest to swampland.
Food and foraging
A gorilla's day is divided between rest periods and travel or feeding periods.
Diets differ between and within species.
Mountain gorillas mostly eat foliage, such as leaves, stems, pith, and shoots,
while fruit makes up a very small part of their diets.
Mountain gorilla food is widely distributed
and neither individuals nor groups have to compete with one another.
Their home ranges vary from 3 to 15 km2 ,
and their movements range around 500 m or less on an average day.
Mountain gorillas have flexible diets and can live in a variety of habitats.
Although both mountain and lowland gorillas have been observed drinking,
Gorillas rarely drink water
because they consume succulent vegetation that is comprised of almost half water
as well as morning dew.
Social structure
Gorillas live in groups called troops.
Troops tend to be made of one adult male or silverback,
multiple adult females and their offspring.
However, multiple-male troops also exist.
and is named for the distinctive patch of silver hair on his back, which comes with maturity.
Silverbacks also have large canine teeth that also come with maturity.
Mature males also tend to leave their groups
and establish their own troops by attracting emigrating females.
However, male mountain gorillas sometimes stay in their natal troops
and become subordinate to the silverback.
If the silverback dies, these males may be able to become dominant or mate with the females.
This behaviour has not been observed in eastern lowland gorillas.
In a single 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.
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 as protection from leopards.
The silverback is the centre of the troop's attention, making all the decisions,
mediating conflicts, determining the movements of the group,
leading the others to feeding sites,
and taking responsibility for the safety and well-being of the troop.
Younger males subordinate to the silverback, known as blackbacks,
may serve as backup protection.
Blackbacks are aged between 8 and 12 years and lack the silver back hair.
The bond that a silverback has with his females forms the core of gorilla social life.
Bonds between them are maintained by grooming and staying close together.
Females form strong relationships with males to gain mating opportunities
and protection from predators and infanticidal outside males.
However, aggressive behaviours between males and females do occur,
but rarely lead to serious injury.
Relationships between females may vary.
Maternally related females in a troop tend to be friendly towards each other
and associate closely.
Otherwise, females have few friendly encounters
and commonly act aggressively towards each other.
Females may fight for social access to males and a male may intervene.
Male gorillas have weak social bonds,
particularly in multiple-male groups with apparent dominance hierarchies
and strong competition for mates.
Males in all-male groups, though, tend to have friendly interactions
and socialise through play, grooming, and staying together,
and occasionally they even engage in homosexual interactions.
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.
Competition
One possible predator of gorillas is the leopard.
When the group is attacked by humans, leopards, or other gorillas,
an individual silverback will protect the group, even at the cost of his own life.
Gorillas do not appear to directly compete with chimpanzees in areas where they overlap.
When fruit is abundant gorilla and chimp diets converge,
but when fruit is scarce gorillas resort to vegetation.
The two apes may also feed on different species, whether fruit or insects.
Gorillas and chimps usually ignore or avoid each other when feeding on the same tree,
but coalitions of chimpanzees have been observed attacking families of gorillas
including silverbacks and killing infants.
Reproduction and parenting
Females mature at 10–12 years (earlier in captivity), and males at 11–13 years.
The gestation period lasts 8.5 months.
Female mountain gorillas first give birth at 10 years of age
and have four-year interbirth intervals.
Males can be fertile before reaching adulthood. Gorillas mate year round.
Females will purse their lips and slowly approach a male while making eye contact.
This serves to urge the male to mount her.
If the male does not respond,
then she will try to attract his attention by reaching towards him or slapping the ground.
In multiple-male groups, solicitation indicates female preference,
but females can be forced to mate with multiple males.
Gorilla infants are vulnerable and dependent,
thus mothers, their primary caregivers, are important to their survival.
Male gorillas are not active in caring for the young,
but they do play a role in socialising them to other youngsters.
The silverback has a largely supportive relationship with the infants in his troop
and shields them from aggression within the group.
Infants remain in contact with their mothers for the first five months
and mothers stay near the silverback for protection.
Infants suckle at least once per hour and sleep with their mothers in the same nest.
Infants begin to break contact with their mothers after five months.
By 12 months old, infants move up to five meters from their mothers.
At around 18–21 months, the distance between mother and offspring increases
and they regularly spend time away from each other.
In addition, nursing decreases to once every two hours.
Infants spend only half of their time with their mothers by 30 months.
They enter their juvenile period at their third year,
and this lasts until their sixth year.
At this time, gorillas are weaned and they sleep in a separate nest from their mothers.
After their offspring are weaned, females begin to ovulate and soon become pregnant again.
Communication
Twenty-five distinct vocalisations are recognised,
many of which are used primarily for group communication within dense vegetation.
Sounds classified as grunts and barks are heard most frequently while traveling,
and indicate the whereabouts of individual group members.
They may also be used during social interactions when discipline is required.
Screams and roars signal alarm or warning,
and are produced most often by silverbacks.
Deep, rumbling belches suggest contentment
and are heard frequently during feeding and resting periods.
They are the most common form of intragroup communication.
A gorilla's chest-beat may vary in frequency depending on its size.
Smaller ones tend to have higher frequencies, while larger ones tend to be lower.
They also do it the most when females are ready to mate.
Intelligent
Gorillas are considered highly intelligent.
A few individuals in captivity, such as Koko,
have been taught a subset of sign language.
Like the other great apes, gorillas can laugh, grieve,
have "rich emotional lives", develop strong family bonds,
make and use tools, and think about the past and future.
Some researchers believe gorillas have spiritual feelings or religious sentiments.
They have been shown to have cultures in different areas
revolving around different methods of food preparation,
and will show individual colour preferences.
That's all I want to say for this video.
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