New bighorn lamb spotted grazing with its mother in Arizona's Pusch Ridge Wilderness.
Credit: Nathan Jackson (Arizona Game and Fish Department).
A pair of lambs was sighted by an Arizona Game and Fish Department official in the Pusch Ridge Wilderness in early February, less than three months after a group of 31 adult bighorns was reintroduced to the area. Mike Quigley, Arizona representative at The Wilderness Society, has been involved in the effort for over a year, and said the lambs were "the first Catalina-born desert bighorn sheep in nearly 25 years," and that such births "used to be a common event and hopefully will be again."
Scientists think that one reason Santa Catalina bighorns faded in the first place was over-suppression of wildfires. Without fire playing its historical and natural role of clearing the landscape periodically and priming it for a fresh cycle of vegetation, varied plant growth had trouble finding purchase. In its absence, thick underbrush ran wild, giving prowling predators the upper hand.
An adult bighorn sheep, one of a group being reintroduced to the Santa Catalina Mountains in Nov. 2013. Credit: Karen McCrorey.
Several years ago, fire cleared out the needed space. That, along with stricter policies against human interference--hikers have specifically been cautioned leave their dogs at home and to stick to established trails during the winter, when bighorns typically give birth—made experts decide this rocky portion of the Coronado National Forest was ready to welcome the big, bounding animals once again. Though the past few months have seen several incidents of local mountain lions killing bighorns, the presence of a new generation of sheep means that state officials’ goal of “restor[ing] a healthy, viable and self-sustaining population coexisting with an equally healthy native predator population in a naturally functioning ecosystem” could be achievable. More broadly, bighorns in parts of the western U.S. have recovered recently after years of deterioration, and these lambs represent another step forward.