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Student essays

KINGDOK - ANIMALIA
PHYLUM – CHORDATA
CLASS – MAMMALIA
ORDER – PRIMATES
FAMILY – HOMINIDAE

3 TYPES OF GORLLAS:
- Western lowland gorilla
- Eastern lowland gorilla
- Eatern mountain gorilla

The gorillas are species in danger,there are not to many of them left in the rainforest today.U can wonder why,because their only natural enemy is the humans! The biggest problems are that humens are hunting for them and the fact that the rainforest, which is their home is getting smaller every day.
Many organisations work hard to save the gorilla population today.

The gorillas is often pictured as agressive animals,but in fact they are shy,peacefull animals living in groups together.
One group consist of 1 old male,the dominant silverblack , 1-3 other males,the subadultds, several females and theire offsprings.
The group may be as large as 30 gorillas.
The silverblack is called so because of the white hair on parts of his body.He is the oldest male in the group and the big protector for the others.The subadults are males up to 15 years,then they are adult and leave the group

So why does gorillas live in groups?

One possebility is the protection from the silverblack and eachother.The silverblack is always the mail protector in the group.
They can also learn from eachother,especially the young ones,they need to lear social behavior from others.This is probably importante to avoid confrontations with other group later on in life.The gorillas dont walk before the age of 8 months,this make them very unprotective and very dependent on the mother and others.
Gorillas are social animals,that may also be one of the reasons to stay in the group.
U could think that it would be easier to mate whitin the group,but only the silverblack are allowed,so this is probably not a reason to stay.

Why does some leave the group?

The males leave the group when they become adults,about15 years old. The main reason for this is to avoid interbreeding. Since only the silverblack can mate int he group,it is a high probability that the females to the younger males are their mother.
The males emigrate if the silverblack are healthy,then they are not likely to mate with females int he group.If the silverblack are ill or likely to die,they may stay and try to get the posotion as the new silverblack
When they leave they challange the silverblack and try to get females to go with them,they may go as far as killing infants to get the mother in estrus earlier and therfor be availible for mating sooner

The range of the females is base upon when she joiner the group.The one that have been int he group the longest is the one closest to the silverblack.The infants gets the same position as their mother. The ones closest to the silverblack get then the best protection from him.

Gorillas are peaceful animald,but theymay be conflicts with other groups.
They try to avoid this be numerous sounds and signals like:

-Roar: only by the silverblack,used when he feels stress,group hide
-Wraagh: stress,also by the silverblack
-Hoot series: used by males seeing members of other groups
-Chest beating: all gorillas to this
-Strtting walk: showing dominance
-Staring: showing aggression

And several other sounds and signals. The gorillas have about 25 different sounds they use Buta re in general quiet animals.

FEEDINGHABITS:

Gorillas feed mainly on leaves, buda, flowers, stal, berries and bark. But thei also eat some insects for the minerals. Thei dont drink much, most of the water they get from the diet.
They are not very active. They sleep about 13 hours every night and during daytime they eat or collect food.
They sleep in nests,in which they buils every night. The female and young often sleep int he trees,but the males slles under.

Gorillas lifespan are about 30-50 years.
Gorillas can be distinguished from eachother by theire nose. Work like a human fingerprint. They recongnise eachother by faces and by bodyshape.

There are not many gorillas letf and the female only has one young every 4 th year.
The mortality of young gorillas are as high as 40%, why?

It can be because of the fact that they are dependent on their mother for a long time, they actually sleep with theire mother until they are 2 yeras old, if the mother are injured og gets ill the young may not survive.
They dont walk before the age of 8 months,need help from theire mother.
If the mother die they need somone else to learn them social behavior. If not they will have problems communicating with other gorillas,importante in this world to read and give signals and signs.
It may also be that the young get injured or ill.
If the silverblack die the group will have less protection until another takes his place. In this period the group is weaker.

The gorillas are a big part of the rainforest and need to be protected against theire only enemy,the humans

Sourses:
- :BBC : Science and nature
- Koko. Org The gorilla foundation