Motorists on the highest parts of the Trail Ridge Road often see the PIKA, which looks like a small, grayish guinea pig but is really a close relative of the rabbit. It is found in the rock slides and talus piles in the high country mostly above treeline, and is seldom seen below 9,000 feet. Despite the subzero temperature of the tundra belt, it does not hibernate. Its habit of storing little bundles of mountain grasses and other alpine plants has given it the nickname of “alpine haymaker”; it is also sometimes called “cony”—a name better reserved for an unrelated Old World mammal. Look for the pika at Rock Cut on Trail Ridge Road, it seems to have favorite sunning spots from which it greets the traveler with shrill shrieks. Coldblooded Vertebrates Many animals do not possess an adequate mechanism for maintenance of constant body heat. Some of these, taking advantage of the slowness with which water changes temperature, live mostly in an aquatic environment. Few can endure the cold winters of high altitudes. Unlike other animals in National Parks, fish may be taken, under regulations designed to conserve the resource. As long as you have a State fishing license, you may exercise this privilege in Rocky Mountain National Park. The season and catch limits vary from year to year; you are urged to ask a park ranger about current regulations. [Illustration: Coyote.] The original trout in the park is the BLACK-SPOTTED, or CUTTHROAT, TROUT. Once found only in the northern Rockies, it has been transplanted widely. It has numerous subspecies and color variations, but here it is usually an olive-green on back and upper sides, shading into a yellowish cast on lower sides. The lower surface becomes red at spawning time. The body and fins are black-spotted. The red streak on each side of the lower jaw has given it the name “cutthroat.” Its principal foods are insects and small aquatic animals. Spawning takes place in midsummer in the high country. The BROOK TROUT, originally native east of the Mississippi, was introduced into this park, where it has thrived and maintains itself through natural reproduction in many lakes and streams. It is olive-green to gray, with a sprinkling of red and gray spots on the sides. The front borders of the lower fins and the lower borders of the tail are white. Its food includes insects, worms, small minnows, and crustaceans. It spawns in autumn; the female deposits the eggs in a depression she scoops out in the streambed. After the eggs are fertilized, she covers them with gravel and leaves them to hatch unattended.