Acoustic direction-finding

Abstract

Many rangelands in the southwestern United States have experienced increased shrub cover and lower and more variable forage resources during the past 100 years. Criollo cattle are descendants of cattle brought to the Americas by European explorers that spread throughout North and South America. These cattle were displaced in many areas as British breeds became popular, but isolated populations remained that had undergone natural selection for nearly 500 years. Scientists at the Jornada Experimental Range in Las Cruces, New Mexico introduced Raramuri criollo genetics from the Tarahumara region of Chihuahua, Mexico to the research herd about 15 years ago in an effort to capitalize on their ability to thrive in harsh landscapes of the Chihuahuan Desert. They hypothesized that this smaller framed animal might be more suited to extensive shrubby landscapes and exert a lower environmental footprint than cattle of European descent. Preliminary observations during the early years of this project suggested that behavioral characteristics of this biotype could potentially be used to improve utilization of extensive rangelands with restricted water distribution. Raramuri criollo generally traveled farther per day and farther from water than Angus x Hereford crossbreds typically raised on these rangelands. Approximately five years ago, the Jornada expanded this program by joining forces with scientists from New Mexico State University, Mexico, and South America. Several studies were initiated that encompassed aspects of behavior, distribution, habitat and ecological site use, maternal behavior, diet selection, heat tolerance, and performance of Raramuri criollo cattle. Many of the results from these collaborations are reported in this special issue.