Western Lowland Gorilla

(Gorilla gorilla)


Facts

Western Lowland Gorilla IUCN CRITICALLY ENDANGERED (CR)

 

Facts about this animal

There are two - geographically separated - gorilla species: the Eastern (Gorilla beringei) and the Western (Gorilla gorilla) gorilla. Each species recognises two subspecies: the Western lowland gorilla (Gorilla gorilla gorilla) and the Cross River Gorilla (Gorilla gorilla diehli) in the western part of Central Africa, and the Eastern Lowland Gorilla (Gorilla beringei graueri) and the Mountain Gorilla (Gorilla beringei beringei) in the easter part. Almost all gorillas kept in zoos outside their range states are Western lowland gorillas. Gorillas are the largest apes. In bipedal standing adult males are about 175 cm heigh. They have an armspan of about 260 cm and weigh about 140-180 kg. In zoos where they may get food too rich in energy and have not enough exercise, weights of up to 270 kg have been recorded. Females are considerably smaller and weigh about 65-135 kg. Gorillas have a bare face, black in colour. The eyes are wide set and deeply sunk under prominent supra-orbital ridges, the iris is brown. The nostrils are flared and surrounded by prominent alar folds. The ears are small, bare and depressed.

In adult males, the head is conically elongated due to the prominent nuchal and sagittal crest surmounting the skull. The arms are considerably longer than the legs, which are outwardly rotated at the hips. The hands are broad, the thumb is relatively short. The foot is plantigrade with a stout, short and well abducted big toe. Coat and skin colour is brownish-black to black. Mature males show a saddle of white or silvery hair across the lumbar region ("silverback"). The coat is short and dense with longer hairs on arms and forearms. Female gorillas sexually mature in the wild between the ages of 7 to 8, at the zoo somewhat earlier. Males sexually mature in the wild between 8 to 9 1/2 years old and at the zoos as early as 6 1/2. Males are not considered fully mature until about 15 years old. Gorillas do not have a distinct breeding season. Gestation lasts from 250 to 270 days. In the wild, female gorillas usually deliver their first offspring at 10 1/2 years old and at four year intervals thereafter. One infant with a birth-weight of 1.8 to 2.3 kg is normally born, rarely twins. The gorillas' diet is predominantly vegetarian: Trees and herbaceous vegetation including leaves, shoots, stalks, stems, vines, bark, fruits and berries. Occasionally they take invertebrates such as termites.

Did you know?
that gorillas never attack people unless surprised, threatened or provoked? Even then, a silverback protecting his clan will first try to intimidate the real or perceived aggressor by standing on his legs and slapping his chest while roaring and screaming.


 

Factsheet
Class MAMMALIA
Order PRIMATES
Suborder SIMIAE
Family PONGIDAE (HOMINIDAE)
Name (Scientific) Gorilla gorilla
Name (English) Western Lowland Gorilla
Name (French) Gorille occidental des plaines basses
Name (German) Westlicher Flachlandgorilla
Name (Spanish) Gorila de Ilanura del oeste, Gorila de planicie occidental
Local names Makaku (Swahili)
CITES Status Appendix I
CMS Status Appendix I

 

This factsheet was compiled by
Peter Dollinger and Silvia Geser, WAZA Executive Office. <br><br><b>Bibliography:</b><br><a href=http://www.cites.org/eng/resources/ID/fauna/Volume1/A-106.009.002.001%20Gorilla%20gorilla_E.pdf target=_"blank">CITES IDM fact sheet</a>

 

Photo Copyright by
Gerald Dick

Distribution

 


Distribution
Range Central Africa (Angola, Cameroon, Central African Republic, Congo, Equatorial Guinea, Gabon). Regionally extinct in the DR of Congo.
Habitat Primary and secondary lowland rain forest, swamp forest
Wild population Accurate population estimates for gorillas are difficult to establish, because their vast range has not yet been thoroughly surveyed. Therefore estimates range between 50'000 to 125'000.
Zoo population 875 registered by the International studbook (2007), 762 reported to ISIS (2009).

In the Zoo

Western Lowland Gorilla

 

How this animal should be transported

For air transport, Container Note 33 or 34 of the IATA Live Animals Regulations should be followed.

 

Find this animal on ZooLex

 

Photo Copyright by
Adrian Pingstone

Why do zoos keep this animal

The gorilla is an endangered species and its habitat is continuously shrinking and deteriorating. With a view of building up a viable reserve population, an International Studbook has been established already in 1967 under the WAZA umbrella, and coordinated conservation breeding programmes are operated at the regional level by AZA and EAZA

 

The gorilla is the largest of all primates and is very popular with the public. Gorillas are therefore ideal ambassadors for their endangered habitat.

 

 

How this animal should be kept

Legal requirements for the keeping of apes vary greatly from country to country. Even if lower national standards apply, it is recommended that an outdoor enclosure of 500 m² and, in cold and temperate climatic zones, an indoor enclosure of 300m² should be provided for up to 5 adult animals. These enclosures should be at least 5 m high. They should be enlarged by 10% for each additional adult. During daytime, access to the outdoor enclosure should be possible whenever weather conditions permit. In- and outdoor enclosures should be connected by at least two doors. The indoor temperature should not fall below 20°C, it should be higher in places (radiators). The day phase should be around 12 hours, the light spectrum should more or less correspond to that of natural sunlight.

 

Vertical and horizontal climbing opportunities, horizontal benches or platforms allowing for sitting at various levels above ground, structures allowing the individuals to retire and avoid one another, and separate cages for temporary isolation should be provided as should toys, and branches and other material for constructing sleeping nests. The outdoor enclosure should have some natural vegetation such as a grass cover, bushes and live trees in addition to dead trees, ropes, climbing frames etc. Live trees may need to be protected by hot wires or similar.

 

Food should be offered at least three times per day, It should contain a lot of crude fibre and consist of a variety of fruit and vegetables, branches in leaf as well as some animal protein.

 

Gorillas should be kept in famil groups or bachelor groups. The keeping of single animals must be avoided.