The water problem is an ever-present one for the mammals as well as the plants. At first this may seem strange with the Green River so close and several springs in the hills, but most of the smaller animals have very restricted ranges. A deer mouse, for example, seldom travels more than 100 feet from his home burrow in his entire lifetime. The kangaroo rat and the desert woodrat also have limited ranges although theirs are somewhat larger than those of deer mice. The majority of such animals must meet their water needs without springs and seeps. How do they do it?
COYOTE. (COURTESY, U. S. FISH AND WILDLIFE SERVICE.)
BADGER. (COURTESY, U. S. FISH AND WILDLIFE SERVICE.)
The food they eat contains some water. The green vegetation of springtime contains large amounts. Even air-dried foods such as seeds contain some. And these animals don’t need much. Through the thousands of years these little creatures have lived in arid lands, evolutionary processes have altered their bodies and life patterns to fit the conditions under which they must live. Surely one of the most useful and interesting of their abilities is that of utilizing metabolic water. Such water is obtained through oxidation of hydrogen contained in food and is a by-product of metabolism. Putting it another way, during the digestive process these animals are able to manufacture water from the chemical constituents of their food and the oxygen in their blood. The amount of water thus obtained is between 70 and 100 percent of the dry weight of the food eaten. Thus some desert animals are able to live a normal life span without ever taking a drink, and probably many of them do.
Carnivores such as the badger and the coyote get some of their water from the animals they eat and may go for days without visiting a spring. But eventually they return to the river or a spring for a drink. This is no special effort as carnivores generally range for miles in search of prey.
Winter is a time of difficulty for most animals. Some of them like the ground squirrels hibernate and sleep the winter away, but the majority must rustle their “daily bread.” Winter storms drive the mule deer down from the high country. Mice tunnel through the snow in search of food. The white-tailed jackrabbit and the snowshoe hare change their coats from brown to white. In particularly hard winters the animals die in great numbers, first the weak and old, then the young, and sometimes even animals in prime condition fail to survive.
The reptiles that make their homes in the Quarry Area of Dinosaur National Monument are few in number. The rattlesnake is rare and seldom seen. The only common snake is the bull or gopher snake. This snake can appear very threatening as it swells its body and hisses loudly, but it is not poisonous. Gopher snakes climb well and are often seen in trees where they hunt for eggs and young birds.
Two lizards are commonly seen here during the summer. The side-blotched lizard is about 1¾ to 2⅛ inches long with a somewhat longer tail. These small brown lizards are frequently seen among the rocks near the parking and picnic areas. The name, side-blotched lizard, is taken from the black or bluish-black area behind the foreleg of the males. These lizards are also called brown utas.