After the females leave their weaned pups to establish new burrows for themselves, the young will remain together for a while until they, too, begin to split up. No longer do they resemble the playful, romping pups of spring, annoying their elders with their ceaseless games, demands for attention, and disregard for territorial boundaries. Now full-fledged members of their clans, they capture grasshoppers in a business-like fashion. Like the season, they have matured. With the company of their elders they now share a suspicion of the sky and every uninspected plot of ground. Lessons a Long Time Learning In the early days of the cattle range, before sound land management of the plains was understood, cattlemen were perplexed to witness mushrooming populations of prairie dogs. Formerly lush grassland often became a dog town “wasteland” following the introduction of cattle. Believing that the prairie dog, and not the cattle, was responsible for this sudden transformation, ranchers rapidly came to despise prairie dogs. A massive war of extermination began against these “varmits” that “ate the grass down to nothing.” In reality, the appearance of prairie dogs merely indicated that the land was being overgrazed. As the bison had done before them, cattle now began to open up to the prairie dogs new territories that they could not otherwise colonize. Prairie dogs were never found on the eastern prairies simply because they could not contend with the taller growth of the more humid grasslands. On their own, prairie dogs cannot easily invade unbroken areas of established grassland. The grass cover simply rejuvenates faster than the animals can work. But if the land has been disturbed by overgrazing, prairie dogs can quickly spread. Once established in an area, the animals wage a constant struggle against the vegetation. Since tall-growing plants offer concealment to a predator, the plants are routinely clipped off even if they are not to be eaten. The feeding, clearing, and burrowing activities of the dog town tend to retard the grasses while encouraging the persistence of forbs—the broadleaf plants that quickly invade disturbed ground but are eventually crowded out by the returning grasses. By arresting the normal process of plant succession, an active dog town delays the return of the site to its climax vegetation of grasses. In so doing, it inadvertently perpetuates a wider variety of plants than would otherwise be found on the site. Selective feeders, prairie dogs put pressure on a particular plant species when it becomes most abundant, then ignore it almost entirely in favor of another, and so on. This cyclic feeding allows each species to recover, preventing it from being eliminated.