Despite abundant grass cover, sharp-tailed grouse and greater prairie-chickens had only moderate nesting success this year on the Fort Pierre National Grassland in central South Dakota.
Wings collected during the first three weeks of the hunting season showed an overall juvenile:adult ratio of 1.6 to 1, markedly lower than the ratio of 2.2 to 1 found in 2018. The average juvenile:adult ratio between 1992 and 2019 was 2.0 juvenile birds harvested for each adult bird harvested.
The juvenile: adult ratio analysis provides biologists with an important index for judging the success of the recently completed nesting season. This year had a sample of 635 wings, compared to last year’s sample of 650 wings and a long-term average of 598 wings. Greater prairie-chickens accounted for 81% of the birds shot in 2019, compared to 70% in 2018 and a long-term (1992-2019) average of 68%.
Dan Svingen, District Ranger for the Fort Pierre Ranger District noted: “This was a challenging year for bird production. Heavy snows from blizzards in late March and early April lingered well into late spring and were followed by unusually wet, cold conditions. We did not see extensive green-up until mid-May, and only started noting abundant grasshoppers, an important food item for growing chicks, in late summer. It appears that the peak of hatching was unusually late, which is often associated with lower bird production. The good news is that the grass growth this summer was phenomenal, hopefully setting us up well for next year’s nesting.”
