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Gorilla

2007 Schools Wikipedia Selection. Related subjects: Mammals

                      iGorillas
   Western Lowland Gorilla(Gorilla gorilla gorilla)
   Western Lowland Gorilla
   (Gorilla gorilla gorilla)

                             Conservation status

   Endangered (EN)
              Scientific classification

   Kingdom:   Animalia
   Phylum:    Chordata
   Class:     Mammalia
   Order:     Primates
   Family:    Hominidae
   Subfamily: Homininae
   Tribe:     Gorillini
   Genus:     Gorilla
              I. Geoffroy, 1852

                                Type Species

   Troglodytes gorilla
   Savage, 1847
   distribution of Gorilla
   distribution of Gorilla

                                   Species

   Gorilla gorilla
   Gorilla beringei

   The gorilla, the largest of the living primates, is a ground-dwelling
   herbivore that inhabits the forests of Africa. Gorillas are divided
   into two species and (under debate as of 2006) either four or five
   subspecies. Its DNA is 97%-98% identical to that of a human, and is the
   next closest living relative to humans after the two chimpanzee
   species.

Name

   The American physician and missionary Thomas Staughton Savage first
   described the Western Gorilla (he called it Troglodytes gorilla) in
   1847 from specimens obtained in Liberia. The name was derived from the
   Greek word Gorillai (a "tribe of hairy women") described by Hanno the
   Navigator, a Carthaginian navigator and possible visitor (circa 480 BC)
   to the area that later became Sierra Leone.

Physical characteristics

   Hand of a Gorilla at San Diego Zoo
   Enlarge
   Hand of a Gorilla at San Diego Zoo

   Gorillas move around by knuckle-walking. Adult males range in height
   from 165-175 cm (5 ft 5 in-5 ft 9 in), and in weight from 140-200 kg
   (310-440 lb). Adult females are often half the size of a silverback,
   averaging about 140 cm (4 ft 7 in) tall and 100 kg (220 lb).
   Occasionally, a silverback of over 183 cm (6 feet) and 225 kg (500 lb)
   have been recorded in the wild. However, obese gorillas in captivity
   have reached a weight of 270 kg (600 lb). Gorillas have a facial
   structure which is described as prognathous, that is, their mandible
   protrudes further out than the maxilla.

   Gestation is 8½ months. There are typically 3 to 4 years between
   births. Infants stay with their mothers for 3-4 years. Females mature
   at 10–12 years (earlier in captivity); males 11–13 years. Lifespan is
   between 30–50 years. The Philadelphia Zoo's Massa set the longevity
   record of 54 years at the time of his death.

   Gorillas are mainly vegetarian, eating fruits, leaves, and shoots.
   Insects make up 1-2% of their diet. Due to their diet of plant life,
   gorillas often have bloated stomachs.

   Almost all gorillas share the same blood type (B) and, like humans,
   have individual finger prints.

Classification

   Until recently there were considered to be three species of gorilla,
   The Western Lowland, The Eastern Lowland and Mountain Gorilla. There is
   now agreement that the gorilla is divided into two species of at least
   two subspecies each. More recently it has been claimed that a third
   subspecies exists in one of these groups.
   Western lowland gorilla
   Enlarge
   Western lowland gorilla
   Female Gorilla at NC Zoo
   Enlarge
   Female Gorilla at NC Zoo

   Primatologists continue to explore the relationships between various
   gorilla populations. The species and subspecies listed here are the
   ones most scientists agree upon.
     * Genus Gorilla
          + Western Gorilla (Gorilla gorilla)
               o Western Lowland Gorilla (Gorilla gorilla gorilla)
               o Cross River Gorilla (Gorilla gorilla diehli)
          + Eastern Gorilla (Gorilla beringei)
               o Mountain Gorilla (Gorilla beringei beringei)
               o Eastern Lowland Gorilla (Gorilla beringei graueri)

   The proposed third subspecies of Gorilla beringei, which has not yet
   received a full latin designation, is the Bwindi population of the
   Mountain Gorilla, sometimes called Bwindi Gorilla.

Endangerment

   Both species of gorilla are endangered, and have been subject to
   intense poaching for a long time. Threats to gorilla survival include
   habitat destruction and the bushmeat trade. In 2004 a population of
   several hundred gorillas in the Odzala National Park, Republic of Congo
   was essentially wiped out by the Ebola virus.

Behaviour

   A silverback gorilla
   Enlarge
   A silverback gorilla

   A silverback is an adult male gorilla, typically more than 12 years of
   age and named for the distinctive patch of silver hair on his back. A
   silverback gorilla has large canines that come with maturity.
   Blackbacks are sexually mature males of up to 11 years of age.

   Silverbacks are the strong, dominant troop leaders. Each typically
   leads a troop of 5 to 30 gorillas and 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.
   Gorilla at the Cincinnati Zoo
   Enlarge
   Gorilla at the Cincinnati Zoo

   Males will slowly begin to leave their original troop when they are
   about 11 years old, travelling alone or with a group of other males for
   2–5 years before being able to attract females to form a new group and
   start breeding. While infant gorillas normally stay with their mother
   for 3–4 years, silverbacks will care for weaned young orphans, though
   never to the extent of carrying the little gorillas.

   If challenged by a younger or even by an outsider male, a silverback
   will scream, beat his chest, break branches, bare his teeth, then
   charge forward. Sometimes a younger male in the group can take over
   leadership from an old male. If the leader is killed by disease,
   accident, fighting or poachers, the group will split up, as animals
   disperse to look for a new protective male. Very occasionally, a group
   might be taken over in its entirety by another male. There is a strong
   risk that the new male may kill the infants of the dead silverback.

Studies

     * The first reference to gorillas was in the diary/history of Hanno
       the Navigator, a Carthaginian prince and sailor. There was some
       debate amongst his men as to whether gorillas were a separate
       species or just a strange tribe of men.

     * 19th Century: The first scientific writings about gorillas dates
       back to the 1847 Proceedings of the Boston Society of Natural
       History, where Troglodytes gorilla is described, with a few other
       species following in the next couple of years.

     * Early 20th Century: The next systematic study was not conducted
       until the 1920s, when Carl Akely of the American Museum of Natural
       History traveled to Africa to hunt for an animal to be shot and
       stuffed. On his first trip he was accompanied by his friends Mary
       Bradley, a famous mystery writer, and her husband. After their
       trip, Mary Bradley wrote On the Gorilla Trail. She later became an
       advocate for the conservation of gorillas and wrote several more
       books (mainly for children). In the late 1920s and early 1930s,
       Robert Yerkes and his wife Ava helped further the study of gorillas
       when they sent Harold Bigham to Africa. Yerkes also wrote a book in
       1929 about the great apes.

     * Mid 20th Century: After WWII, George Schaller was one of the first
       researchers to go into the field and study primates. In 1959, he
       conducted a systematic study of the Mountain Gorilla in the wild
       and published his work. Years later, at the behest of Louis Leakey
       and the National Geographic, Dian Fossey conducted a much longer
       and more comprehensive study of the Mountain Gorilla. It was not
       until she published her work that many misconceptions and myths
       about gorillas were finally disproved, including the myth that
       gorillas are violent.

Intelligence

   Gorillas are closely related to humans and are considered highly
   intelligent. A few individuals in captivity, such as Koko, have been
   taught a subset of sign language (see animal language for a
   discussion).

Natural tool use by all the "great apes"

   A female gorilla exhibiting tool use by using a tree trunk as a support
   whilst fishing.
   Enlarge
   A female gorilla exhibiting tool use by using a tree trunk as a support
   whilst fishing.

   The following observations were made by a team led by Thomas Breuer of
   the Wildlife Conservation Society in September 2005. Gorillas are now
   known to use tools in the wild. A female gorilla in the Nouabalé-Ndoki
   National Park in the Republic of Congo was recorded using a stick as if
   to gauge the depth of water whilst crossing a swamp. A second female
   was seen using a tree stump as a bridge and also as a support whilst
   fishing in the swamp. This means that all of the great apes are now
   known to use tools.

   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 forty years previously chimpanzees had been seen using tools in
   the wild, famously 'fishing' for termites. Other animals also use
   tools, e.g. sea otters use rocks on their chests to break sea urchins.
   It is a common tale among native peoples that gorillas have used rocks
   and sticks to thwart predators, even rebuking large mammals. 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. With training, in 20th Century carnival and
   circus acts, chimpanzees have been taught to operate simple motorbikes.

Gorillas in pop culture

   Giant gorillas have been a recurring theme in film since the 1930s.
   Following their popularity in the 1930s and 40s, most notably in the
   films King Kong, Tarzan, and Mighty Joe Young, gorillas came to be
   heavily featured in comic books. Short contrived gorilla plots were
   often included so that they could appear on the cover to boost sales.

   Gorilla suits are an eternally popular gag costume, appearing in large
   numbers of TV shows since the 1950s. A number of sports teams have a
   gorilla as a mascot usually personified by an actor in a gorilla suit.

   Retrieved from " http://en.wikipedia.org/wiki/Gorilla"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
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