Unit 4 Primates

Chapter 15

Apes Great and Small

Swingers: Gibbons

• Rainforest• Arboreal• Eat fruits, leaves, eggs• Coat and facial colors• Vocal patterns• Move by brachiation• Small• Long fingers and small

thumb• Do not sleep in nests• monogamous

Orangutans

• Solitary, shy (only together mating)

• Rainforest Sumatra, Borneo• Adult males 165 lbs, 8 ft

arm span• Females half size (sex

dimorphism)• 50 year life span• Eat fruit, forage a lot• Males territorial, charging,

some fighting• Females parent alone

Gorillas

• Shy and gentle• Live in small family

groups• Silverback is alpha male

over harem• Rainforest, plants and

fruit, forage• Ground dwelling, hands

and feet not specialized for trees

• Knuckle walking

• Silverback leads troop single file

• Protects, finds food• Silver at about 11

yrs and older• Groups 8-24• Silverback and

blackbacks lookout for trouble

Threat gestures

• Tight lips• Eye contact• Growls, pants• Teeth baring• Stiff strut• Chest beats• Charges (bluff,

slam, fight-rare)

Submission gestures

• Cower• No eye contact• Bite lip• Yawn• Groom others• Fake eating

• Gorillas cont.• Nap and eat during day• Elaborate night nests

on ground or higher up• Females do not mate w/

relatives• Females solicit male

attention, bond to alpha male

• Gorillas cont.• Young learns social

structure• Caring mothers• Ride on belly or

back for many years

Chimpanzees

• Share 99% of DNA w/ humans

• Chimps, gorillas, humans are distinctly diff

• Humans did NOT come from chimps!

• We share a distant common ancestor before there were such things as chimps, gorillas, or humans. 3-4 mya

Chimpanzees

• Western and central Africa

• Forest, woodlands, savanna

• Eat fruits, leaves, insects, meat

• Males 90 lbs, females 70 lbs

• Arms longer than legs• 45 year life span• Nest at night

• Walk on knuckles • Live mostly on ground• Use tools• Variety of facial

expression, body gestures, calls

• Genitals swell during estrus

• Females present themselves

• Young are cared for many years

• Rank associated w/ mother

• Males dominant and aggressive

• Loose hierarchy• Form coalitions,

manipulate for power• Hierarchy changes over

time• Complex relationships

Dominance gestures

• Charging• Hair erect• Use props for sight

and noise• Grunting• Screams

Submission gestures

• Bobbing• Crouching• Pant grunting• Fear grin• Grooming

Groups vs.. community

• Groups• AKA party• 3-6• Related• Live w/in community

• Community• 15-120• Larger territory

• Females migrate out, males stay

• Females must join group where other females accept her

• Group hunting: driver, blockers, chasers

• Group defense of territory

Chimps go to war

• Border patrol parties• Raiding parties• Group holds male

down while others beat him

• Safety in numbers• Need to be a part of

group• Use weapons

Bonobos

• Similar in size to chimps

• Diff build and facial structure

• Live more south• Walk upright easier• No fear of water

(web-like toes)

• Live in large communities

• Female dominated• Use of sex for bonding• Same sex bonding as

well• Used to avoid or solve

conflict• Maintain harmony (not

dominance)

Can apes use language?

• Can learn sign language

• Learn to use computers

• Use objects to communicate with humans

Conclusions to studies:

• 1. Can learn symbol systems to comm

• 2. Can string together symbols

• 3. Abilities exceed other non-human primates

• 4. Short sentences

• 5. Symbols are objects or actions