Pronghorn Population Management Program
The Arizona Game and Fish Department will continue a successful program to help the state's struggling antelope population. The department will conduct limited lethal removal of coyotes in three limited areas, beginning in early April, to help increase fawn survival rates.
The removal efforts will be conducted in these wildlife management units: Unit 21, near Cordes Junction; Unit 10, north of Seligman; and Unit 3A, northwest of Snowflake.
Arizona's antelope populations have struggled the past several years because of a number of factors, including extended drought, poor habitat conditions and coyote predation. The department is trying to help antelope in areas where herd declines have been severe.
"Research has shown that loss of fawns due to predation by coyotes can be one of the major limits to growth of pronghorn populations," says Pat Barber, department biologist. "Fawns are most susceptible to predation during the first few weeks of life. Data shows that coyote control measures, applied for a very limited time at the right time of year, can greatly improve fawn survival."
Pronghorn populations in several areas received a boost following coyote removal efforts in 2003 and 2004. An example of the benefits of the effort is in Wildlife Management Unit 10, which had been annually averaging just 14 fawns per 100 does in the six years prior to coyote reduction measures. Following those efforts in Unit 10's Aubrey Valley area, the numbers in that area jumped to 56 fawns per 100 does in 2003, and 52 per 100 in 2004.
Department biologists believe this winter's rains will create favorable conditions for a good fawn crop, and ample vegetation growth that can provide both food and hiding cover for newborn fawns.
"By doing limited, short-duration coyote management during wet periods when fawn production is greatest, we can give those antelope a much-needed boost," says Barber. "Reducing predation just before pronghorn fawns are born will give the vulnerable newborns a chance to survive long enough so they can escape predators. Without intervention, we could see continued long-term declines in these localized antelope populations."
Biologists say other factors impacting pronghorn populations in the state include loss of habitat through development or through encroachment of woody plants, and habitat fragmentation from road building and fences.
Game and Fish biologists say it typically takes three years of decent fawn survival for antelope herds to become stable. "Our protocol calls for doing three consecutive years of coyote removal to help a pronghorn herd get back on its feet," says Barber. This will be the third year of the removal program for Units 10 and 3A, and the first for Unit 21.
Coyote control is a short-term effort to assist antelope herds in trouble. Game and Fish biologists continue to work with land management agencies, conservation groups, ranchers, and other interested groups to address long-term habitat concerns.