Sage grouse numbers predicted to decline in '18Jan 2, 2018 From staff reports
Wyoming's closely-watched sage grouse population is expected to shrink in 2018, according to data analyzed by the Wyoming Game and Fish Department.
Using information based on evaluation of sage grouse wings provided by hunters, the state analysts determined that in 2017 there were 1.2 chicks per hen, compared to 0.9 chicks per hen in 2016. This number mirrors the 10-year average from 2007-2016.
Typically, biologists would like to see numbers of 1.4-1.6 chicks per hen to maintain population stability, a Game and Fish report states.
The sage grouse was considered for federal endangered species status in recent years, but that designation has been avoided so far.
Hunters contribute to the management of sage grouse annually by assisting Game and Fish in the data collection. Wing data is gathered from hunters who voluntarily deposit wings in barrels scattered across central and southwest Wyoming. More than 2,000 wings were collected in 2017, and wings from 924 chicks and 767hens were examined.
"By looking at the ratio of chicks to hens, it gives us a good idea of what our reproduction was for this year," said Tom Christiansen, sage grouse program coordinator for the Wyoming Game and Fish Department, "and that helps us predict what our lek counts will be next year in terms of whether there will be more birds or fewer birds based on this year's reproduction.
Wyoming has the largest number of sage grouse in the nation. Fremont County has the highest grouse population in the state.
In addition to collecting the wing data, department personnel and other partners also visit more than 1,600 grouse leks, or breeding grounds, to count the numbers of sage grouse visiting on each lek.
Christiansen said the extreme winter experienced in western Wyoming last year had a minimal effect on sage grouse production. If anything, he noted, mortality is usually at its lowest during the winter months. Summer drought is considered to the biggest natural threat to the fowl.