gorillas in our midst

Gorillas In Our Midst.

• The Gorilla: The Largest Living Species of Primate.

Geographical Range of Gorillas.

Family Pongidae.

Gorilla Taxonomy.

• Up to four subspecies of Gorilla gorilla are currently recognized.

• I: Western Group:• A) Gorilla gorilla gorilla, The Western Lowland

Gorilla.• B) G. g. diehli, The Cross River Gorilla.• II. Eastern Group.• C) G. g. graueri, The Eastern Lowland Gorilla.• D) G. g. beringei, The Mountain Gorilla.

Western Lowland Gorilla, G. g. gorilla.

The Cross River Gorilla, G. g. diehli.

Eastern Lowland Gorilla, G. g. graueri.

The Mountain Gorilla, G. g. beringei.

Mountain Gorillas.

Gorilla Morphology.

• Large Size.• Arms longer than legs.• Sexual dimorphism in size, males up to 200kg,

females 70-100 kg.• Knuckle walkers/quadrupedal.• Sagittal Crest, especially in males.• Subpecies differentiated by shape of nostrils,

relative size and robusticity, and body hair.

Skull with Sagittal Crest.

Gorilla Skeleton.

Gorilla Polygynous Social Groups.

• Groups composed of one adult “Silverback” Male and several females, plus offspring.

• Group numbers range from 7-11 individuals in mountain gorillas.

• Immature “Blackback” males may remain with group until maturity.

• Mountain gorillas are the most studied subspecies.

Gorilla Home and Day Range.

• Gorilla home ranges vary depending on the habitat and subspecies in question.

• Home ranges can be as large as 100 ha.

• Day ranges average about 500 meters.

Gorilla Diet.

• Gorillas are the most folivorous of the Great Apes.

• Some fruit is eaten.

Gorilla Reproduction.

• Extreme K selection.

• Gorillas give birth to one offspring at a time.

• Gestation is about 256 days.

• Birth intervals between 36 and 59 months, depending on the subspecies.

Mother and baby.

Conservation Status of Gorillas.

• All Gorilla subspecies are protected by CITES

• Habitat loss is a major threat.• Poaching and the bushmeat trade are major

threats too.• Diseases, such as Ebola, have devastated

both gorilla and chimpanzee populations in the Odzala National Park in Zaire.

Population estimates.

• Between 10,000 and 20,000 Western Lowland Gorillas.

• Up to 10,000 Eastern Lowland Gorillas.

• Between 350 and 650 Mountain Gorillas.

• Between 100-200 Cross River Gorillas.

Gorilla survival in the future.

• Depends on Ecosystem and Habitat protection.

• Protection from poaching and bushmeat trade.

• Reproduction in captivity.

• New discoveries?