Healing the Wounds: An Example from the Sky Islands - Design with the Desert: Conservation and Sustainable Development - page 194

• Over a century of ire suppression has eliminated a natural disturbance regime
vital to the integrity and function of forest, woodland, and grassland ecosystems.
• The region has been fragmented by roads, dams, and other works of civilization,
potentially isolating wide-ranging species in nonviable habitat islands.
• Aggressive and disruptive exotic species, both plants and animals, have invaded
or been purposefully introduced, threatening ecosystem integrity and the sur-
vival of individual species.
• Beginning in the 1870s with cutting for mine timbers, railroad ties, and irewood
and continuing to the present day with industrial logging operations, all forest
types in the region have been degraded.
Other ecological wounds have occurred as well, but these six are the most pervasive and
destructive.
10.2.1 Wound 1: Loss of Important Species
Causes: During the preceding 200 years or so, native animals—carnivores, large ungulates,
keystone rodents, and other species—have been extirpated or greatly reduced in numbers
by (1) trapping, (2) market hunting, (3) competition from domestic livestock, (4) diseases
introduced by settlers and domestic livestock, (5) livestock fencing, (6) predator and rodent
control, (7) trophy and fur hunting, and (8) transformation of natural habitats for different
human uses.
One species, the imperial woodpecker, and two (perhaps three) subspecies are extinct
because of hunting, poisoning, trapping, and habitat destruction: Merriam's elk, the
Mexican grizzly, and likely the Arizona river otter. In addition, desert bighorn sheep, Rocky
Mountain bighorn sheep, pronghorn, and even javelina, mule deer, and Coues white-tailed
deer were nearly extirpated around 1900. The bison was probably extirpated, although a
handful of survivors may have persisted in northwestern Chihuahua. Except for 20 or so
individuals reintroduced recently to the Apache National Forest of Arizona, the Mexican
wolf has been extirpated in the wild, although a few individuals may remain in remote
areas of the Sierra Madre. Breeding populations of jaguars, ocelots, and jaguarundis were
reduced or eliminated in the United States. Mountain lions and black bears also declined
sharply. Two keystone rodents—beavers and prairie dogs—suffered tremendous declines
(Figure 10.2). Thick-billed parrots and aplomado falcons were extirpated from Arizona and
New Mexico. The Tarahumara frog disappeared from the United States by the early 1980s. 8
American trappers entered the Sky Islands region (then part of newly independent
Mexico) in the 1820s. 9 Beavers were abundant in the Gila, Rio Grande, and Little Colorado
watersheds. By the 1840s, beavers were functionally extinct in the Sky Islands region, as
they were throughout what is now the western United States. 10,11 Market and hide hunters
killed off the southern herd of bison in the 1870s. 12 In the Sky Islands, mining camps sprang
up in the 1870s, drawing market hunters who slaughtered pronghorn, deer, javelina, big-
horn sheep, turkey, and even thick-billed parrots to feed the miners. Authorities on the
thick-billed parrot believe that hunting may have been the main cause for its disappear-
ance from the United States. 13 The largest subspecies of elk, Merriam's, was abundant in
the Mogollon Highlands (now the Gila and Apache National Forests). This subspecies may
have ranged south through the Sky Islands ranges and valleys into Mexico, but reports
are inconsistent. 14 They were completely exterminated by hunters: the last few individuals
were shot on Fly's Peak in the Chiricahuas in 1906. 12