GUNS, GERMS AND STEEL - Cloverport Independent Schools

ZEBRAS AND UNHAPPY MARRIAGES • 173
ranking female, followed by her foals in order of age, with the youngest
first; and behind her, the other mares in order of rank, each followed by
her foals in order of age. In that way, many adults can coexist in the herd
without constant fighting and with each knowing its rank.
That social structure is ideal for domestication, because humans in
effect take over the dominance hierarchy. Domestic horses of a pack line
follow the human leader as they would normally follow the top-ranking
female. Herds or packs of sheep, goats, cows, and ancestral dogs (wolves)
have a similar hierarchy. As young animals grow up in such a herd, they
imprint on the animals that they regularly see nearby. Under wild conditions
those are members of their own species, but captive young herd animals
also see humans nearby and imprint on humans as well.
Such social animals lend themselves to herding. Since they are tolerant
of each other, they can be bunched up. Since they instinctively follow a
dominant leader and will imprint on humans as that leader, they can
readily be driven by a shepherd or sheepdog. Herd animals do well when
penned in crowded conditions, because they are accustomed to living in
densely packed groups in the wild.
In contrast, members of most solitary territorial animal species cannot
be herded. They do not tolerate each other, they do not imprint on
humans, and they are not instinctively submissive. Who ever saw a line of
cats (solitary and territorial in the wild) following a human or allowing
themselves to be herded by a human? Every cat lover knows that cats are
not submissive to humans in the way dogs instinctively are. Cats and ferrets
are the sole territorial mammal species that were domesticated,
because our motive for doing so was not to herd them in large groups
raised for food but to keep them as solitary hunters or pets.
While most solitary territorial species thus haven't been domesticated,
it's not conversely the case that most herd species can be domesticated.
Most can't, for one of several additional reasons.
First, herds of many species don't have overlapping home ranges but
instead maintain exclusive territories against other herds. It's no more possible
to pen two such herds together than to pen two males of a solitary
species.
Second, many species that live in herds for part of the year are territorial
in the breeding season, when they fight and do not tolerate each other's
presence. That's true of most deer and antelope species (again with the
exception of reindeer), and it's one of the main factors that has disqualified