Sage grouse populations in northeastern Wyoming have declined from last year.
Surveys of the spring sage grouse populations within the Sheridan Region of the Wyoming Game and Fish Department suggest a nearly 30 percent decrease in numbers compared to the 2000 results, according to a news release from Warren Mischke, Wyoming Game & Fish information specialist.
Department personnel, federal agency biologists, wildlife consulting firms and volunteers conducted checks of nearly 160 sage grouse strutting grounds in April and May. Results from theses surveys form the basis for trend analysis in the sage grouse population.
Leks a drawEach spring, Game & Fish personnel check sage grouse leks. Leks are dancing groundstraditional breeding areas.
According to Mischke, Most of the leks are used every year with many leks having continuous attendance going back over 40 years. Many of the leks within the Sheridan Region are checked each spring where counts are made of the number of male and female sage grouse on the lek. Such lek checks are used as indices of population trends. As numbers increase, more birds are typically observed on the leks. When populations decrease, fewer birds are observed on the leks.
There are about 260 known sage grouse leks in the Sheridan Region. Of these, 40 are considered to be historical leks, that is, they have been used continuously for a number of years and havent been disturbed by mining, subdivisions, or agricultural activities.
Fewer dancersMischke says, In 2001, about 160 leks were checked by area personnel, or nearly 60 percent of the known leks. Overall, the average number of males per lek in 2001 was 10.2. This compares to an average of 14.9 males per lek in 2000, which was the highest average in 10 years. Results suggest a decrease in sage grouse numbers of about 30 percent.
Sage grouse populations throughout North America have been declining for a number of years. There are many theories why sage grouse are declining. One theory is that the treatment and eradication of large areas of big sagebrush has caused the decline. Other theories state that diseases have eliminated the birds. Predators are another possible cause of the decline.
Reasons for dropAccording to Mischke, Research has shown that one of the major factors influencing sage grouse populations is the quality of nesting and brood rearing habitats. Sage grouse need good cover during this critical time to avoid predation by mammals and birds.
Drought conditions in 2000 resulted in very poor range conditions during the summer. Poor habitats most likely resulted in fewer grouse successfully raising a brood of chicks. Fewer chicks in 2000 mean fewer adult birds on the leks in 2001. With drought conditions prevalent this summer, it is expected that sage grouse numbers will continue to decrease.
Other birds declineMischke continued, Sage grouse numbers were on the increase from 1997 through 2000 with each year showing a higher average of birds on the leks. More precipitation and fairly mild conditions during those years resulted in better nesting successes by sage grouse. Similar trends were also observed of sharp-tailed grouse and gray, or Hungarian partridge, as numbers of these birds also jumped considerably over the past three years. Drought conditions in 2000 most likely affected sharp-tailed grouse and gray partridge.
Though there are huntable populations of sage grouse, hunters will find that this falls sage grouse season will be a tough one. The same holds true for sharp-tailed grouse and Hungarian partridge.
The season for sage grouse opens Sept. 22 and runs until Oct. 7.
Bob Krumm, of Sheridan, is the Wyoming outdoor correspondent for The Billings Gazette. Contact him firstname.lastname@example.org.