Pronghorn

Home on the r nge

Where the pronghorn antelope play ronghorn antelope are only found in North America. Although they are often referred to as "antelope," they are not closely related to any African antelope species. The name "pronghorn" is derived from the prong on each horn.

Pronghorn have an amazing speed of almost 60 mph. Approximately 10,000 American pronghorn are found in Arizona, mainly in the north-central area of the state. Their range encompasses a variety of grassland habitats ranging from desert grasslands to forest and mountain meadow.

Unfortunately, grasslands over 5,000 feet are mostly privately owned and, therefore, subject to development.

"This loss has taken out of production not only 15 to 20 percent of the antelope's habitat in Arizona but also the highest quality areas," said David E. Brown, ?iologist at Arizona State University.

Energy development projects and ranching also chip away at important available habitat. Much of the remaining habitat on state and private land has been invaded by vegetation such as junipers, mesquites and acacias. But perhaps the biggest factor facing antelope conservation today is habitat loss due to fragmentation and development.

"In our part of the country, we may have thousands of acres of what appears to be contiguous antelope habitat, but pasture fences are built with woven or low bottom wires and antelope won't be able to access the seemingly available habitat," said Henry Provencio, wildlife biologist ar Coconino National Forest. This prevents the animal from accessing wildlife corridors.

"Depending on the size of the fragment, the species viability could be at stake," he added.

In northern Arizona, I-40 effectively separates pronghorn habitat. Pronghorn habitat north ofi-40 and south ofl-40 have "little to no interchange of pronghorn from either side of the freeway," Provencio continued. During the recent

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Page 8 • March 2010

By Lili DeBarbieri

Photo courtesy National Parks Service A photographer gets up close and personal with a pronghorn antelope.

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Photo by john]. Mosessollife. nbii.gov Pronghorns prefer to cross under fences.

Photo courtesy Arizona Game and Fish Department A pronghorn antelope mom and her fawn make their way across the grassland.

real-estate boom, Arizona experienced a great deal of pronghorn habitat loss due to development. Housing subdivisions often fragment these otherwise continuous habitats.

To combat the situation, agency biologists, ranchers, sportsmen, and environmentalists created the Anderson Mesa Pronghorn Plan in northern Arizona.

The Plan identifies goals and strategies to improve the Anderson Mesa herd.

"The folks funding projects wanted to take a landscape level approach at restoration treatments, state and federal biologists created a nearly 500,000-acre landscape approach to treatments," Provencio explained.

He further stated that "working together with NGOs [nongovernment organizations] we have increased the permeability of range fences by raising the bottom strand of wire to 18" and installing "goat bars," where wildlife trails cross either over or under fences.

"Prescribed fire and managed natural fire have also been used to improve over 25,000 acres of habitat," he said. "Ranchers, NRCS, NGOs and sportsman groups collaborated to restore over 50,000 acres of juniper-encroached grasslands."

The Arizona Wildlife Federation, The Arizona Game and Fish Department,

Diablo Trust, Arizona Antelope Foundation and the National Forest Foundation have created small wildlife refuges around "29 ephemeral wetlands that are important water sources for pronghorn and other species," Provencio said.

Every year, the Arizona Antelope Foundation sponsors three or four work projects to conserve the habitat of pronghorn antelope. Usually, the work projects are weekend undertakings that are topped off with a steak dinner on Saturday night and breakfast on Sunday morning.

Volunteers remove old barbed wire fences and posts, woven sheep fences and install new antelope-friendly fences. They also cut pinon and juniper trees that encroach on pronghorn occupied meadows.

Each work project is different depending on the location and need. Volunteers are always needed and welcomed.

Hunting is another important tool for antelope conservation. Sportspersons generate "dollars that have been the funding source for many brush removal projects, translocations, land-owner agreements, controlled burns, fence modifications and other habitat management measures," Brown said.

What is the future of Arizona's charismatic antelope?

"The only long-term habitat security

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Courtesy photo A pronghorn antelope relaxes.

for this animal in Arizona is on federal land, mostly U.S. Forest Service land such as Anderson Mesa, and some BLM areas such as the Arizona Strip," Brown said. "The antelope in these areas, however, frequently suffer from the same habitat ailments as those on state land, including competition with excessive numbers of cattle and elk."

For more information about pronghorn, or for details on the next weekend work program, see www.azantelope.org.

March 2010 • Page 9

Photo courtesy ofJohn Hervert A Sonoran Pr~nghorn and her fawn are in a captive breeding enclosure at Cabeza Prieta National Wildlife Refuge.

Public can comment on recovery plan n 2002, only 21 endangered Sonoran pronghorn lived in the United States. Today, an estimated 68 animals are thriving, thanks in part to extensive cooperative management efforts, captive breeding, irrigation for forage and protection from predation. Now, the species is ready for the next step-recovery.

The U.S. Fish and Wildlife Service has drafted an environmental assessment as part of the process to establish a second U.S. population into its historical habitats of southwestern Arizona.

To allow for greater management flexibiliry in the reintroduction effort, the plan proposes that these new populations be designated as "experimental, nonessential populations."

The public can submit comments on the proposals by: U.S. mail to Cabeza Prieta National Wildlife Refuge, Attention: Refuge Manager, 1611 N. Second Ave., Ajo, AZ 85321; Fax: (520) 3875359; E-mail: James_Atkinson@fws.gov or online: www.regulations.gov, reference Page 10 • March 2010

document id FWS-R2-ES-2009-0077.

The draft environment assessment for establishing additional locations is available for review at www.fws.gov/ southwest/es/Library or by contacting the Cabeza Prieta National Wildlife Refuge at 520-387-6483.

"The experimental designation allows a more collaborative approach, garners support, and helps develop partnerships berween stakeholders, landowners, and other federal, state and local officials," said Eric Gardner, nongame branch chief for the Arizona Game and Fish Department.

"Multiple populations for a species are critical to recovery efforts and are more desirable than one population because they help prevent a single regional catastrophic event (e.g., disease, weather events, high predation rate) from causing the entire species or population to disappear from an area or altogether become extinct."

Background The United States Fish and Wildlife Service listed the Sonoran pronghorn

(Antilocapra americana sonoriensis) as endangered in 1967. The U.S. population of Sonoran pronghorn has been affected by habitat fragmentation, loss of perennial rivers and extreme drought.

Several steps have been taken to prevent the extinction of Sonoran pronghorn, including closure of areas to traffic during fawning season and provision of summer forage.

Another strategy for population recovery is establishment of additional populations. Multiple populations are more desirable than a single population because they prevent a single regional catastrophic event (e.g., disease, weather events, high predation rate) from causing the entire species to become extinct.

Recovery criteria for the Sonoran pronghorn state the need for a second population of Sonoran pronghorn to be established in the United States and the current population to number at least 300 individuals, or for the current population to reach a size that will promote a stable population.

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