The Ecology Book

124 USING ANIMAL MODELS TO UNDERSTAND HUMAN BEHAVIOR

Chimps may fight over territory

in order to acquire more resources

or mates, but some primatologists

maintains that such aggression is

unnatural and provoked by human

impact on their habitat.

Such behavior has implications

for human evolution. Science has

long questioned why and when

humans first began eating meat.

From prehistoric stone tools and

marks on bones, paleontologists

know that the early hominids

were using stone tools to cut meat

from animals bones 2.5 million

years ago, but it is not known

what they were eating between

then and 7 million years ago,

when the common ancestor

of chimpanzees and humans

is thought to have lived.

It is likely that these early

hominids hunted prey. Although

they did not have large canine

teeth like chimpanzees, these are

not necessary for hunting and

killing small prey. Biologists have

observed that chimps hunting

colobus monkeys grab them from

the trees and then kill them by

repeatedly thumping the bodies

on the ground; early hominids

could have hunted and killed

in a similar fashion long before

the earliest known tools.

Cooperative behavior

Another aspect of chimps’ hunting

behavior that is similar to that

of humans is the social element.

Although chimps sometimes hunt

alone, hunting tends to be a group

activity. Chimps rampage through

the forest, coordinating their

positions and surrounding their

prey. After the hunt, the food is

shared. This shows how early

ancestors of humans may have

developed cooperative behavior,

a factor that may have contributed

to their evolutionary success.

Chimp warfare

A shocking revelation that came

out of the Gombe camp was that

chimps are capable of violence,

murder, and in particular warfare—

once believed to be the preserve

of humans. Between 1974 and 1978,

Jane Goodall watched as her

peaceful community of chimps

fractured into two rival groups that

then waged savage war on each

other. Goodall was deeply upset

about the chimps’ activity, which

included ambushes, kidnappings,

and bloody murder. The trigger

Conservation of chimpanzees

According to the Jane Goodall

Institute in Tanzania, the number

of chimpanzees living in the wild

has plummeted over the last

century. In 1900, there were an

estimated 1 million chimpanzees

in Africa; today, there are fewer

than 300,000. Habitat loss due to

a rising human population in need

of more space has had a huge

impact, as have industries such

as logging and mining, which

destroy habitat and fragment

chimp communities when roads

are built through their territories.

Roads also encourage another

damaging activity—hunting

for bushmeat, a highly valued

meat in Africa that includes

great apes. Roads enable

hunters from towns to travel

directly into the bush. The

protection of chimps focuses

on land conservation and on

raising awareness both locally

and across the globe.

Orphaned chimps—their mothers

killed for bushmeat—walk along a

mud track with their keeper at a

conservation center in West Africa.

for the war was unclear; some

researchers blamed the feeding

stations Goodall had set up in the

area, which may have encouraged

unnatural congregations of chimps.

The answer to the mystery came

in March 2018, when a research

team at Duke and Arizona State

Universities, US, digitized Goodall’s

meticulous check sheets and field

notes from 1967 to 1972 and fed

them into a computer in order to

analyze the social networks and

alliances of all the male chimps.

Their findings revealed that the

fracture in the community occurred

two years before the war broke

out, when an alpha male Goodall

called Humphrey took over the

troupe, alienating two other high-

US_118-125_Using_animal_models_to_understand_human_behaviour.indd 124 12/11/18 6:24 PM