Environmental Engineering Reference
In-Depth Information
of hundreds of species since the beginning of the early modern era (the other one
being the loss of habitat due to deforestation and grassland and wetland conversion).
In 2010 the most reliable global count of animal species that have become extinct
since 1500 surpassed 700 (IUCN 2011), but there is no doubt that the actual total
is substantially higher. Most of the disappearances have been among rodents and
birds, particularly the smaller ones and the inhabitants of smaller islands.
The list also includes more than a dozen large mammals, above all a number of
grazers, among them African quagga (
Equus quagga
), the red and Arabian gazelles
(
Gazella arabica
), tarpan (
Equus ferus
), the Portuguese ibex (
Capra pyrenica lusitan-
ica
), and the Syrian wild ass (
Equus hemionus hemippus
); among large carnivores
the most notable subspecies losses were those of the Bali, Java, and Caspian tigers
(
Panthera tigris balica
,
sondaica
and
virgata
) and the Barbary and Cape lions (
Pan-
there leo leo
and
melanochaitus
). In absolute terms, no post-1500 extinction of a
vertebrate species surpasses the fate of America's passenger pigeon (
Ectopistes
migratorius
). Flocks of this species were composed of tens to hundreds of millions
birds, with the total continental count in the billions. John James Audubon recalled
how in 1813 on the banks of Ohio, “the air was literally i lled with Pigeons; the
light of noon-day was obscured as by an eclipse, the dung fell in spots, not unlike
melting l akes of snow; and the continued buzz of wings had a tendency to lull my
senses to repose.”
And Mark Twain's memoirs recall their antebellum surfeit: “I can remember the
pigeon season, when birds would come in millions, and cover the trees and by their
weight break down the branches. . . . They were clubbed to death with sticks; guns
were not necessary” (Twain 2010). By the time the last surviving passenger pigeon
died in 1914 it was several decades since the massive l ocks had disappeared. The
slowly declining numbers of the birds plummeted once the pigeons became massively
hunted to supply inexpensive meat: during the 1870s some counties in Michigan
were shipping east every year a million or more of the birds, giant l ocks were gone
by the 1880s, and small l ocks survived into the 1890s; the last wild l ock of some
250,000 birds was annihilated in 1896 (Eckert 1965). Even if we assume that “only”
two billion birds were killed between 1840 and 1890, that slaughter (with an
average live weight of 350 g/bird) would have amounted to 700,000 t of avian
zoomass.
But when measured in terms of the total wild zoomass destroyed by human
actions, none of the post-1500 extinctions has involved such an open and deliberate
mass slaughter as did the virtual elimination of the American bison (
Bison bison
)
in North America before 1900 (I will deal with the nineteenth- and twentieth-
