Lecture Notes: Gorilla Overview

Introduction to Gorillas

• Gorillas are herbivorous, ground-dwelling great apes from equatorial Africa.
• Two species: Eastern Gorilla and Western Gorilla, with 4-5 subspecies.
• DNA similarity with humans ranges from 95-99%.

Scientific Classification

• Domain: Eukaryota
• Kingdom: Animalia
• Phylum: Chordata
• Class: Mammalia
• Order: Primates
• Family: Hominidae
• Genus: Gorilla

Physical Characteristics

• Largest living primates.
• Height: 1.25 to 1.8m; Weight: 100 to 270kg.
• Arm span: Up to 2.6m.
• Age in wild: 35-40 years.

Habitat and Distribution

• Inhabit tropical/subtropical forests in Sub-Saharan Africa.
• Range includes various elevations.
• Eastern gorillas: Albertine Rift montane forests.
• Western gorillas: Central West Africa.
• Estimated populations: 316,000 western, 5,000 eastern.

Conservation Status

• Classified as Critically Endangered.
• Threats: poaching, habitat destruction, disease.

History and Etymology

• Name derived from Hanno the Navigator's encounter.
• Initially described in 1847 by Savage and Wyman.

Evolution and Classification

• Closest relatives: chimpanzees and humans.
• Diverged from a common ancestor ~7 million years ago.

Variations and Subspecies

• Eastern Gorilla: G. beringei
  • Mountain gorilla, Eastern lowland gorilla
• Western Gorilla: G. gorilla
  • Cross River gorilla, Western lowland gorilla

Characteristics

• Males weigh 136-227kg, females 68-113kg.
• Silverbacks: Mature males with a silver patch on their back.
• Dark brown eyes, individual fingerprints.

Behavior and Social Structure

• Live in troops led by a silverback.
• Troop dynamics involve grooming and protection.
• Strong bonds within troop, especially female-male.

Reproduction

• Females mature at 10-12 years, males at 11-13 years.
• Gestation period: 8.5 months.
• Maternal care is crucial for infant survival.

Communication

• 25 distinct vocalizations for group communication.
• Chest-beating as a signal of size and readiness to mate.

Intelligence and Tool Use

• Known for tool use, e.g., using sticks to gauge water depth.
• Capable of learning sign language in captivity.

Significant Studies and Conservation Efforts

• Conservation efforts include international treaties and projects.
• Threats include diseases like Ebola and habitat encroachment.
• Notable conservation successes in certain regions.

Cultural Significance

• Gorillas have featured in folklore and popular media, often portrayed as aggressive but can also be depicted sympathetically.
• Examples include King Kong, Gorillas in the Mist.

This summary covers the primary characteristics, habitats, behaviors, and conservation status of gorillas, incorporating their biological classification and notable research findings.