How Domesticated Animals Changed the World - The Darwinian Tourist - page 198

Humans have had a dramatic impact on their environment for a long
time. The earliest Americans, like the earliest migrants to Madagascar and
New Zealand, seem to have killed of most of the large animals that they
found in their new homelands. These human-caused extinctions, some
better documented than others, have been termed the “Pleistocene overkill”
by Paul Martin of the University of Arizona. 7
There are many questions about the role of humans in the widespread
extinctions of horses, camels, mastodons, and saber tooth cats that took
place 10,000 years ago in North America. The evidence for human overkill
in mastodon extinctions is strong and growing. 8 But was human over-hunt-
ing entirely responsible, or did the changing climate at the end of the last Ice
Age play a role? And did dogs, which we know accompanied the fi rst human
migrants to the New World, help their human masters to drive so many spe-
cies to extinction?
The evidence is much stronger that humans killed of the giant fl ightless
birds of Madagascar and New Zealand. We also know that dogs accompa-
nied the fi rst Maori settlers to New Zealand seven hundred years ago. The
fi rst European explorers saw these kuri dogs being used to hunt small birds,
and as a source of food. 9 But we do not know whether dogs also helped the
Maori to hunt the giant fl ightless moas, the last of which disappeared not
long before Captain Cook landed there in 1769.
The Maori dogs themselves disappeared soon after Cook's arrival,
replaced by more useful European breeds.
On a personal note, having tramped through some of the steep, thickly
forested slopes of New Zealand's South Island, I cannot see how the Maori
could possibly have hunted down the last moas in those remote regions
without the aid of tracking dogs.
Loren Eiseley and others have questioned whether humans were really
responsible for many cases of apparent Pleistocene overkill. And why, they
ask, did most of the large animals of Africa survive even though our ances-
tors hunted them for millions of years? Paul Martin responded by pointing
out that extinction rates in Africa actually did increase at the same time as
human infl uence was spreading. About forty percent of the large animal
genera in Africa have disappeared in the two and a half million years since