Sage Grouse numbers from Wyoming Game & Fish
Sage Grouse production in Wyoming was up slightly in 2019 compared to the year before. In this week’s Game and Fish Report, Ray Hageman says the data indicates sage grouse numbers are right at levels for maintaining population.
Sage grouse reproduction was up slightly in 2019 compared to 2018, based on preliminary data from the wings of harvested chicks and hens. The wings are collected from hunters — primarily in central and southwest Wyoming — who voluntarily contribute sage grouse wings by dropping them off at designated collection points during the hunting season.
Typically, sage grouse populations rise and fall in cycles, so biologists look at trends or averages over a longer period of time. The collected wings give an estimate of sage grouse reproduction and the number of chicks recruited into the fall population. In 2019, biologists counted 667 hen wings and 740 chick wings. This information helps the Wyoming Game and Fish Department determine the average number of chicks per hen that were produced for the year. Used in conjunction with spring lek counts, wing data gives Game and Fish insight into how sage grouse populations are doing in Wyoming.
Last year, Game and Fish documented 0.8 chicks per hen. Data for 2019 shows there were 1.1 chicks per hen. The recent rise in chicks is close to the population maintenance ratio. The average for maintaining populations is approximately 1.2 chicks per hen; a population that’s growing has 1.5 chicks per hen, or more. Again, the ups and downs in chick production are all part of the cycle of sage grouse populations.”
Wing data is just one tool Game and Fish uses to estimate sage grouse population. Department personnel and other partners also visit over 1600 leks, or breeding grounds in Wyoming to count the numbers of sage grouse visiting on each lek. Hunters contribute to management of sage grouse by assisting Game and Fish Department in data collection when they deposit sage grouse wings in barrels scattered across central and southwest Wyoming.
Good moisture and habitat contributes to chick survival. During their first month of life, sage grouse chicks rely on a high-protein diet of insects. Spring and summer rains lead to increased grass and forbs like wildflowers, which in turn leads to more insects available for young birds. A full analysis will be available in the sage grouse job completion report, which will be available on the Game and Fish website this spring.