The Kaibab squirrel has been called the handsomest squirrel in America, but this rodent's showy white tail and tasseled ears do a lot more than look good. Its unique natural history has led scientists to compare Sciurus aberti kaibabensis with Darwin’s finches in terms of evolutionary significance. The Kaibab squirrel is a member of a complex natural system found nowhere in the world but northern Arizona, where the squirrel and its habitat have evolved in isolation for hundreds of thousands of years.
The Kaibab Plateau forms the physical and ecological heart of north-central Arizona. To the north lie Utah’s Grand Staircase--Escalante National Monument, Zion National Park, and Bryce Canyon National Park, from which herds of mule deer and mountain lions annually migrate south. Navajo Nation lands and the Vermillion Cliffs National Monument fall to the east, while the Grand Canyon forms the meandering southern border. The Kaibab Plateau connects these otherwise isolated landscapes, forming a critical linkage between the spectacular canyons, mesas, and cliffs of the region. Wildlife such as goshawks and pronghorn antelope rest, feed, and care for their young in the wooded corridors of the Kaibab Plateau.
From an aerial perspective the Plateau appears as an island of green surrounded by arid, ocher lands. This island is one of the world’s greatest examples of an old growth ponderosa pine forest, the conifer with which the life of a Kaibab squirrel is intimately bound. The tree provides nesting sites and food for the squirrel, which evolved to depend upon the seeds, shoots, and twigs of the ponderosa pine. Even the Kaibab squirrel’s favorite mushroom is an underground truffle that grows exclusively with the roots of conifers. In return, the mammal helps maintain the vigor of ponderosa stands. Across its range, the Kaibab squirrel cracks open the pine’s hard cones, distributes seeds, cycles nutrients such as nitrogen, and spreads beneficial truffle spores. This remarkable symbiosis developed over millennia; restricted by desert on all sides, the tree and the Kaibab squirrel became a pair.
--Erin Weeks / photos courtesy of Allyson Mathis for the U.S. National Park Service and the U.S. Forest Service, Southwest Region, Kaibab National Forest.
This post is part of a series on threatened American landscapes. Intensive logging, hunting, and livestock grazing threaten the ancient relationship between the ponderosa pine and the Kaibab squirrel. President Obama can protect the North Kaibab area by naming it a national monument under the Antiquities Act. Sierra Club activists across the West are encouraging him to do so. Follow the campaign at www.sierraclub.org/habitat.
