Animals (continued)

Animals of the Canyons and Mountains

Another heavy-bodied lizard found in the monument is the chuckwalla. Buff to slate colored, it prefers rocky locations and is usually found about the mouths of canyons or on slopes or mesas where there are large boulders or ledges. Unlike most reptiles, the chuckwalla is a vegetarian, feeding upon tender leaves, flowers, and fruits. Its chief method of defense is to attempt escape by crawling into a crevice among the rocks, where it inflates its lungs, thus wedging itself tightly. If cornered, it lashes at its tormentor with its stout tail. Chuckwallas are preyed upon by hawks and coyotes; Indians at one time considered their flesh a delicacy.

Some desert mammals and birds move up into the mountains in summer, thus escaping the intense heat of the lower levels and finding food more abundant. Others, such as the bighorn, prefer the higher parts of the mountains all year, but they are occasionally seen crossing the wide desert valleys apparently en route to another mountain range. These animals are timid and, because of the inaccessibility of the higher parts of the rugged Ajos and Growlers, few persons have had an opportunity to study them in these native haunts. The bighorn, one of the Southwest's most spectacular large mammals, finds refuge and suitable habitat within the monument and in the Cabeza Prieta Wildlife Refuge, which adjoins it on the west.

Another mammal occasionally seen at higher elevations is the Arizona form of the white-tailed deer, or Coues deer. Smaller than the mule deer of the cactus desert and mesquite-bordered washes, the white-tailed deer favors oak thickets and brushy canyon slopes, where it browses on various shrubs and small trees. It is especially fond of acorns.

Frequenting moist locations in mountain canyon bottoms are two small amphibians. The red-spotted toad is active principally at night, but it is sometimes found abroad during the day. The high-pitched cricketlike trill of the male is a pleasant spring and summer-evening sound along canyon bottoms in the Ajo Mountains. The black tadpoles of this species are noticeable throughout the summer wherever there are shallow pools. The Couch's spadefoot, another toad, frequently breeds in temporary puddles during the summer rainy season. Following rain, the adults are sometimes seen during the day although they are normally nocturnal. Like all toads, they are insect eaters. The tadpoles are an iridescent coppery bronze color, shading to black.

In winter, the small, sprightly rock wren inhabits rocky outcroppings in the creosotebush desert and broken lava boulders on cactus-studded slopes of mesas. When summer comes, it moves to dry, open mountain slopes, where it nests on ledges or on the ground in clefts between boulders. These cheerful little insect eaters seem quite unafraid of humans. They often may be approached closely and will come to their nests to feed their young when people are near.

About the same size as the rock wren, the rusty, brown-speckled canyon wren is shy and prefers steep cliffs and deep, rugged, shady canyons. Often heard but seldom seen, it has a loud, clear whistle that trips down the scale in a series of rapid notes, attracting immediate attention. Cave mouths and shelves beneath overhanging rocks are its favorite nesting sites.

A bird of the oak thickets and brushy mountain slopes is the big, fluffy brown towhee, which stays at the higher elevations throughout the year. These birds are ground dwellers, scratching noisily among dead leaves in the thickets. They usually build nests in low shrubs or cactuses.

Although no nests have been reported, the Cooper's hawk probably breeds among the cliffs and canyons of the Ajo and Growler Mountains. These swift, powerful predators feed on other birds, which they catch in flight, and on rabbits and other small mammals. Preferring the rugged crags and canyons of mountain terrain, they often invade the lower areas where doves, quail, and other large birds are more abundant.

Ground squirrels, woodrats, rabbits, and many other species of small mammals, reptiles, and birds inhabit the mountainous parts of the monument, but nothing definite is known about them locally because few observations have been recorded and no extensive studies have been made within the monument. Although the area was among the first on the continent to be explored by Europeans, it is among the last to be studied scientifically. The mountainous parts offer unlimited opportunities for investigation, the first step of which should be the compilation of an inventory listing the many forms of plant and animal life to be found there.