Central Arizona Wildlife Alliance

 The American Pronghorn (Antilocapra americana)

Paleontological History

From The American Pronghorn and Its Ancient Relatives by Richard S. White

"The American Pronghorn was long considered endemic, that is, it evolved in North America and had no close relatives in the Old World. The earliest fossil relative of the living pronghorn in North America is about 28 million years old. A wealth of different kinds of pronghorn appeared after that time, with all but one species, the living pronghorn, becoming extinct." 

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Life History

From Centennial Edition: Arizona Pronghorn  by the Arizona Wildlife Federation

Pronghorns are a favorite animal for visitors to the southwest, and they have a special place in the hearts of Arizona conservationists and outdoor enthusiasts. While they are often called antelopes, they are in their own phylogenetic family. They are also an incredibly important part of Arizona’s ecosystems.  They weigh up to 100 pounds and measure three to five feet in length ... they are one of the few mammals with true horns. The Pronghorn is the last surviving member of its family, the Antilocapridae.  Long before European colonization, millions of pronghorn ranged west across open plains from the central U.S. to eastern California, north into southern Canada and south into northern Mexico.

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Central Arizona Grasslands, A Crucial and Diminishing Resource

From the Arizona Game and Fish Department's Grassland System Overview

"Grasslands in Arizona occur primarily on State Trust, BLM, Tribal, and private lands, a significant portion of which is classified as working landscapes where livestock grazing is the primary land use. While grazing practices on many ranch lands and allotments have been modified in recent years to align with a more sustainable lands approach, overgrazing especially in arid environments can cause undesirable changes in the plant community, including decreasedmulch cover, decreased water infiltration, compacted soil, increased water runoff, decreased plant vigor and production, and a drier microclimate at ground level (Severson and Medina 1983). In light of climate change and long-term drought, already stressed grasslands can be further impaired. In some places, introduced non-native plants (such as Lehmann lovegrass and cheatgrass) have invaded the natural vegetation and caused landscape-level changes that may be irreversible. In addition to grazing pressures, Arizona’s grasslands are at risk of loss to development, especially on private and State Trust lands, which have no long-term conservation protection (Gori and Enquist 2003)."

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