intervention like the prongh... VIEW ORIGINAL
YUMA PROVING GROUND, Az.-- They call it the prairie ghost.
The sobriquet for the Sonoran Pronghorn, squat and reddish brown with white patches and dramatic horns, was originally coined to describe the creature's elusive nature and blazing speed--about 60 miles per hour at full trot across its favored desert flats.
But the nickname took on a grimmer connotation in 2002 when a severe drought decimated the pronghorn's already-fragile population. At its nadir, fewer than two dozen of the creatures remained in all of Arizona before rain and supplemental feedings stabilized their numbers.
"We were within a few weeks of losing these animals as well," recalled John Hervert, terrestrial program research manager for the Arizona Game and Fish Department. "The herd was slowly dying of starvation and it was a predictable thing: you could see them losing weight with each passing week."
Thanks to an intense effort by state and federal wildlife agencies, there are now more than 300 pronghorn in the state. Since 2011, officials have begun transferring the animals into historic habitat within the borders of the Kofa Wildlife Refuge and U.S. Army Yuma Proving Ground (YPG).
As a natural laboratory for testing virtually every piece of equipment in the ground combat arsenal, YPG has a vested interest in responsible stewardship of the land. Despite being the busiest of the Army's six test centers and boasting the longest overland artillery range in the United States, a relatively small portion of the proving ground's vast ranges are subject to artillery impact on a given day. It is located in one of the nation's most extreme climates, but the proving ground is home to a vast diversity of wildlife, including desert tortoises and bighorn sheep.
Though it is an endangered species, the experimental nature of the transported population means the proving ground is subject to a legal designation that allows pronghorn to repopulate here without adding much in the way of regulatory hurdles to the YPG mission.
"If an animal is accidently injured or killed as a result of our routine mission actions, it doesn't put us in violation of the law," explained Daniel Steward, YPG wildlife biologist. "The only requirement we have is to report a dead pronghorn within 24 hours of finding it and coordinating access to recover the carcass for study. If you were to find a dead one here, it was most likely killed by a predator, not any of YPG's activities."
YPG's wildlife biology program coordinates access for the Arizona Game and Fish Department to conduct regular monitoring of the sheep population, including twice-monthly overflights of the range to track pronghorn equipped with GPS and telemetry collars.
"We build predictive habitat models from that data as well," said Larisa Harding, terrestrial program research manager for Arizona Game and Fish. "We want to know if there are areas that they could use across YPG or Kofa for future release purposes that they are not using now."
YPG and Arizona Game and Fish also utilize trail cameras at manmade water stations across the proving ground and the wildlife refuge to monitor pronghorn activities, and credit the construction of these low maintenance oases that capture rainwater from running washes as a critical factor in the pronghorn's progress toward recovery.
"In the past, the common thought was that pronghorn got all of their water needs filled by their food sources," said Steward. "We now know how important standing water is to pronghorn populations."
A raw, rainy desert winter day in January brought 60 individuals from multiple wildlife agencies and universities to prepare more than 20 pronghorn for release into the wild from their half-mile square breeding pen on the Kofa National Wildlife Refuge. To vaccinate and tag the animals prior to their release, they are drawn into a livestock enclosure called a boma that consists of three circular enclosures covered by shade cloth. As the animals migrate into the enclosure closest to the veterinary stations erected under pop-up tents just outside the boma, a crew files in through a sliding gate and uses a long net to capture each sheep. The walls of this last enclosure are padded in case the animal is able to jump prior to being subdued.
"Pronghorn are made for running, not jumping," said Steward. "They are very powerful and can jump very high, but their bodies can't handle it. To keep injuries to a minimum, our goal is to get them subdued before they get a chance to jump."
Once subdued, the adult pronghorn are brought to the veterinary stations on stretchers with holes that accommodate the creatures' powerful legs. On this day, Steward's role was to monitor each animal's temperature as the veterinarians outfitted them with a telemetry collar and drew blood and scat samples. If the animal's temperature rose too high, it was doused with water to prevent fatality.
"One of the biggest challenges of handling wild animals is body temperature rising as a reaction to stress," explained Steward. "It is more acute with pronghorn: imagine taking a high-end sports car and holding its rear wheels off the ground while flooring the accelerator."
To minimize stress, the dozens of people in the crew work quickly in virtual silence, and the animal's head is covered. Young fawns who aren't ready to be released into the wild are attended to inside the boma while being held in the arms of a strong volunteer. It isn't easy work: even the young pronghorn have powerful legs, and the men's clothes begin to sport rips ridged with smears of blood as the day progresses.
Once they are vaccinated and collared, the animals meant for release spend several days in a holding pen adjacent to the breeding pen prior to being released, to ensure that any injuries or other after-effects of being handled have passed. After that, they are released into the wildlife refuge, with the potential to migrate into YPG.
"We are very hopeful that YPG is going to be a critical part of the recovery of this subspecies of pronghorn," said Hervert.
"There is a tremendous investment in every one of these pronghorn," added Steward. "We want to support them as much as we can."
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