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Great Apes Comparison

Aug 5, 2025

Overview

This lecture compares the physical traits, habitats, behaviors, and strengths of silverback gorillas and orangutans, exploring which might be considered "king" of the great apes.

Silverback Gorillas: Social Leaders

  • A silverback is a mature male leading a gorilla troop of 5–30 members.
  • Responsible for deciding troop movements, foraging, resting, and safety.
  • Silverbacks get their signature silver "saddle" at about 12 years old.
  • Males are 5.5–6 ft tall (1.6–2 m) and weigh up to 350 lbs (160 kg).
  • Females are smaller, up to 5 ft tall (1.5 m) and 200 lbs (90 kg).
  • They have long, thick hair for insulation at high altitudes.
  • Social, affectionate, and sometimes display aggression to defend troop.

Orangutans: Arboreal Giants

  • Orangutans are the largest tree-dwelling mammals, found only in Asia (Sumatra and Borneo).
  • Males average 4.5 ft tall (1.36 m), 191 lbs (87 kg); females are smaller.
  • Notable for long, red hair, bare faces, and large cheek pads in adult males.
  • Extremely long arms (up to 7 ft span) help with swinging through trees.
  • Orangutans are mainly solitary, especially adult males.
  • Display advanced cognitive skills like tool use, reasoning, and planning.
  • Endangered due to habitat loss for palm oil plantations; extinct in some areas.

Habitat and Range

  • Gorillas inhabit tropical forests in central and west Africa, with different species adapted to various elevations.
  • Mountain gorillas live at higher altitudes; western and eastern gorillas occupy lower tropical forests.
  • Orangutans prefer swampy, lowland forests near water, rarely found above 500 m.
  • Sumatra orangutans are fully arboreal due to ground predators; Borneo orangutans can be terrestrial due to fewer predators.

Diet

  • Gorillas eat 97+ plant species, also termites and ants; adult males may eat 60–70 lbs daily.
  • Orangutans are primarily frugivores, eating 400+ plant species and adjusting diet during low fruit seasons to include leaves, bark, and insects.
  • Orangutans possess strong spatial memory for foraging.

Behavior and Strength

  • Gorillas are gentle, social, and shy, but defend their troop using displays or physical force.
  • Orangutans are placid, inventive, and solitary; males show aggression mainly toward other males.
  • Gorillas are generally stronger, better built for terrestrial combat, and use physical dominance socially.
  • Orangutans avoid confrontation, excelling in climbing rather than fighting.

Gorilla vs Orangutan: Hypothetical Fight

  • Gorillas have size, ground movement, and fighting advantage over orangutans.
  • Orangutans rely on agility and avoid direct conflict.

Key Terms & Definitions

  • Silverback — Mature male gorilla with a silver saddle, troop leader.
  • Flanged Male — Adult male orangutan with large cheek pads.
  • Frugivore — Animal that primarily eats fruit.
  • Troop — Social group of gorillas.
  • Arboreal — Living in trees.

Action Items / Next Steps

  • Review differences in ape behavior and adaptation for upcoming quiz.
  • Read about palm oil’s impact on orangutan habitats.