Ghostly grazers and Sky Islands
This article is part of a larger document. View the larger document here.Abstract
The evolution of the western range involves millions of years of coexistence of herbaceous plants with a great many kinds of large herbivores, most of the latter suddenly removed around 13,000 years ago. The fossil record indicates more diversity of large herbivores before this time, not less, and with more taxa of large herbivores consuming more forage than livestock eat at present. With extinction of megafauna coinciding with Clovis colonization around 13,000 years ago, large herbivores and their herbivory decreased. Most of our large native herbivores vanished when these prehistoric people invaded. In addition the invaders triggered a considerable surge in fire frequency, declining historically with the introduction of domestic livestock. As archaeologists and geographers have long realized, environmentalists must not overlook or ignore but embrace prehistory.