All 31 of the bighorn sheep released into the Catalina Mountains on Nov. 18 apparently have survived so far and are fanning out across the range, state wildlife officials said Wednesday.
“So far, so good,” said Mark Hart, spokesman for the Arizona Game and Fish Department. “They’re generally in the historic range for bighorns, and they’re doing well at this point as far as we can tell from the data we’re receiving” from global positioning system collars on the animals.
The sheep, captured in mountains near Yuma on Nov. 16 and 17, were “transplanted” to the Catalinas in an effort to rebuild a herd that died out there in the 1990s. Twenty-four ewes, six rams and one yearling ram were released along the Romero Canyon Trail at Catalina State Park north of Tucson — and they quickly bounded away into the mountains.
“It looks like one of the sheep is as far north as the mountains in an area near Biosphere 2” southwest of Oracle, Hart said.
He said another half-dozen bighorns have made their way east from the release site to the slopes of Mount Lemmon.
“Most of the remainder are in the Pusch Ridge area including Pima Canyon, and one animal has made its way as far east as the west fork of Sabino Canyon,” Hart said. “They are pretty widely dispersed, but they are tending to hang together in smaller groups of three, four or six animals.”
In previous transplant operations, sheep have tended to regroup into more cohesive herds after fanning out initially, Hart said.
He said wildlife officers studied the Catalinas well in advance of the release and found “good habitat from upper Sabino Canyon all the way (west) from there to Pusch Ridge” at the southwestern end of Catalinas.
“Part of what makes
Pusch Ridge so good is that it is so rough that it doesn’t get as many hikers,” who might impact the bighorns’ behavior, Hart said. “It’s the most rugged and least accessible part of the range. But where the sheep go is up to them.”
COLLARS WILL COME OFF
The GPS collars fitted on the sheep help wildlife officers track bighorn movements and determine when a sheep dies — marked by the cessation of movements.
“We’d love to think there will be no mortalities, but there will be,” Hart said. “In the natural order of things, there will be mortalities — whether from accident, a misstep or a predator.”
The collars aren’t intended to remain with the sheep indefinitely.
“The collars come off automatically when the battery dies — after maybe two years,” Hart said.