KINGMAN - The Arizona Game and Fish Department has its first confirmed sheep crossing.
Cameras caught the two rams making their way across one of three overpass bridges Feb. 1. Zen Mocarski, public information officer for the Kingman Game and Fish office, said one of the rams was seen crossing in one direction in the morning and then returning in the opposite direction four hours later.
The crossings were part of a $4.8 million project between the Game and Fish Department, the Arizona Department of Transportation and the Arizona Desert Bighorn Sheep Society. The idea was to use the opportunity of the highway widening to look at ways to protect both drivers and the sheep by preventing herd fragmentation, as well as motorist-sheep collisions. Before traffic was rerouted around the Hoover Dam after Sept. 11, 2001, that stretch of highway saw 10 or more collisions a year between the sheep and vehicles. Most occurred within 20 miles of Hoover Dam.
Work on the project began almost 10 years ago, after plans were made to widen U.S. 93 to a four-lane highway. U.S. 93 runs through the Black Mountains, which holds the largest contiguous desert bighorn population in the nation. Populations at their peak reached around 1,800. That number declined to a low of 400-500 in 2007. There are now believed to be around 800 sheep in the mountains.
Desert bighorns are similar to their cousins, the Rocky Mountain bighorn, but they've adapted to life in the desert. The Black Mountains wind north to south along the eastern side of the Colorado River and hold about one-third of Arizona's bighorn population.
Mocarski said the project was done in three stages. The first stage included catching the sheep so that they could be outfitted with collars that would track their movement along U.S. and Highway 68 from Kingman to Bullhead City.
At first, researchers looked at the underpasses already in place on Highway 68.
"It wasn't enough for us to say this is where we're going to put in the underpass," Mocarski said. "We had to figure out if and where they were using them."
Turns out, the sheep were skittish about going under the road and popping out the other side, where predators could be lurking. Researchers then looked at the idea of overpass wildlife crossings, which have been used in the United States for other animals, but never before for the bighorn sheep.
The bridges include a system of fences on either side of the road, which are designed to "funnel" the sheep to the crossings. Locations were selected based on more than 100,000 "data points" collected as a result of the collaring effort.
The studies showed that the sheep had several preferred crossing areas where they approached the highway from ridgelines. The bridges are wide and designed to give the sheep a clear view of where they're headed. It is presumed that once the sheep learn to use them, they will teach their offspring. The bridges were finished late last year and Mocarski said fencing was finished last month.
The bridges cost less than $2 million each. Many have asked why so much money was spent to protect the sheep when they're just going to be hunted anyway?
Mocarski said the project was about protecting both sheep and drivers. He added that the sheep are hunted very conservatively.
Less than 100 sheep hunting permits were issued in 2010 for the state of Arizona, with only 19 of those permits issued for the Black Mountains. The number of permits issued is based on a percentage of older rams as observed during the Game and Fish Department's helicopter census.
A bighorn sheep's age is based on the length of the horns since they are not shed.
Mocarski said the number one cause of wildlife isn't extinction, but fragmentation and habitat loss, which the overpasses help minimize.
Only males are hunted, he added, meaning there's little to no impact on the overall population since they mate with numerous females.
Mocarski also said that when there are problems with the bighorn population, it is often hunters who are first to sound the alarm, such as when numerous dead sheep were found earlier this decade as a result of drought and disease.
Money from the permits for a sheep hunt also helps fund conservation efforts, he said.
Permits cost $272 for an in-state resident and $1,400 for out-of-state residents, but can fetch as much as $300,000 at auction based on the limited number available.
That money is then reinvested back into conservation efforts, such as efforts to increase the population after it plummeted to an all-time low of 400 several years ago.
"We're starting to see a rebound from that and that is a direct result of efforts funded by selling those permits," Mocarski said.
In fact, since 1984, permits have accounted for nearly $25 million worth of funding.
Funding for the new overpass crossings came from Game and Fish, the state Highway Department and the Arizona Desert Bighorn Sheep Society.
For more information on the project, visit www.azgfd.gov/w_c/research_maintain_sheep.shtml. Clips of the sheep using the crossings have been uploaded to You Tube and can be found by searching "U.S. 93 Bighorn Sheep Crossing."