File:The continent we live on (1961) (20496729620).jpg

Title: The continent we live on
Identifier: continentweliveo00sandrich (find matches)
Year: 1961 (1960s)
Authors: Sanderson, Ivan Terence, 1911-1973
Subjects: Physical geography; Natural history
Publisher: New York : Random House
Contributing Library: New College of California
Digitizing Sponsor: Internet Archive

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The Yellowstone Rivo- rises in the Rockies, then descends onto the prairies, loses impetus, and begins to meander and to cut a deep gutter. stemmed shrubs, followed in turn by hardy trees such as the beautiful, useful, but in many respects almost indestructible Mesquite, which has now moved up from southern Texas as far as Kansas and is being held back only by considerable effort from that area of western Texas called the Llano Estacado. The Prairie Dog was master and part maker of the prairie, but he was not alone. There was, and still is, another burrower and an even more profound one. This is the Pocket Gopher, a really appalling- looking creature, with tiny eyes, vast front teeth stuck out at the end of a fully furred but bony snout, powerful front legs with huge claws for digging, little trundling hind legs, and a loose- skinned tail that can be used as a feeler when the animal goes backward, which it can do as readily and as fast as it can go forward. Unlike the Prairie Dog, the Pocket Gopher spends almost all its time down below, endlessly burrowing and throw- ing up small mounds of excess earth. The Pocket Gopher (not to be confused with the plain gophers or ground squirrels) does not live where the Prairie Dog is found, or vice versa. On the pure grasslands there is nothing below the surface but grass roots, and these are not acceptable to the Pocket Gopher. They need bulbs and roots, so they go to work under areas where herbs, bushes, and trees grow. There they do a very effective job of "mowing" all those types of vegetation from underneath, thus eliminating them. The part played by these animals under natural conditions was to hold back, if not actually to push back, the scrub and chaparral on the south and the parkland woods on the north of the Prairie Belt. They did this by cutting off the individual plants of these types at the base of their stems just as soon as they gained a footing, and then toting these treasures down into the subsoil and stowing them away in caches. The efficacy of their efforts may be dramatically demonstrated when a parcel of these animals moves into a young and thriving orchard. They move down the lines of young trees at a surprising rate, cutting them off neatly just below the surface so that, within hours, they wilt, die, and topple. I have seen them completely destroy a thriving citrus plantation in the tropics in one night. The Pocket Gophers had—and still have—few enemies except for certain fungoidal diseases that periodically decimated their ranks, for they are agile at digging, and drill their tunnels deep into the subsoil. NATURE'S BALANCE The Prairie Dog, on the other hand, once had many enemies, which is to say—if we would be more biologically precise—it formed the staple item in a large food cycle, for animals do not, of course, have "enemies." Prairie Dogs shared their dominions with a large number of other creatures, notably burrowing owls, 154

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