Annual Ranges of Pronghorn in the South of Interstate 40 Herd in Arizona

The South of Interstate 40 (I-40) pronghorn (Antilocapra americana) herd make one of Arizona’s most remarkable migrations. This herd resides primarily in GMU 8, which had a population estimate of 450 individuals in 2019. Unlike traditional summer-winter range dynamics, this pronghorn herd relies on a complex of several important seasonal ranges connected by narrow corridors. Migration between ranges appear to be driven by winter conditions, thus, the timing of the movements is highly variable. The herd has high fidelity to these corridors, which elevates the importance of research and management efforts to conserve them. During the summer, these pronghorn inhabit large grasslands in and around Garland Prairie. During migration, animals move westward, parallel to I-40 passing through densely forested habitat before stopping on grasslands in Putney Flat. After some time there, many individuals move even lower in elevation, traveling south to winter range on Wagon Tire Flat and open meadows north of the Verde River. Some individuals cross the Verde River, traveling through the Juniper Mountains as far south as US-Highway 69. High-volume roads including I-40 and State Route 89 present the largest threats to movement for this herd. These roads also appear to influence the herd’s movement patterns along this corridor, as pronghorn rarely cross them. These data provide the location of annual ranges for American pronghorn from the South of Interstate 40 Herd in Arizona. They were developed from 43 annual sequences collected from a sample size of 24 animals comprising GPS locations collected every 2 hours.