Date of this Version
In 1999, a project was implemented for the protection of antelope fawns in two areas of Carbon County, Wyoming. The project was funded by the Wyoming Animal Damage Management Board (ADMB) for the benefit of two antelope areas that were having trouble rebounding to their normal population levels after the severe winters of 1991 and 1992. While the Wyoming ADMB project’s main focus was on enhancing pronghorn antelope fawn recruitment, the benefits of coyote population management could have “spillover” benefits to cow/calf producers in the coyote removal areas.
With the decline of the value of coyote fur in the late 1980s, coyote populations have increased in many areas of Wyoming, including ADMB area 63 and ADMB area 55, the two geographic areas in the study (Merrell and Shwiff, in review). ADMB area 61, another geographic area, was the control site. At the ADMB two predator management sites, there are, on average, 4,095 cows giving birth every spring. Since the decline of the sheep industry in these areas in the mid-1970s, no significant coyote management had been conducted. A study on the relationship of coyotes to mule deer fawn recruitment, done on and around area 63 in 1976-79, estimated the area’s coyote population at 1 coyote/ 20.6 square miles (Springer and Wenger, 1981). Population data from the ADMB project for pre-treatment coyote populations in 1999 were 1 coyote/ 2.2 square mile, a nine-fold increase (Merrell and Shwiff, in review).
Prior to 1972, coyote populations had been suppressed by the use of broadbased poisons such as 1080, thallium and strychnine. After the ban on poisons, coyote populations continued to be suppressed by people hunting and trapping for fur. Many cow/calf producers who historically had been operating in lowcoyote population densities, felt that coyote predation on calves was not at a level to cause concern. Our study suggests that these coyote populations should be a serious economic concern to both the producer and the consumer.