Grouse annual drumming survey results from the WI DNR report an overall statewide decline of 34%. The Northern Zone index declined an even greater amount, 38% to 1.28 drums per stop. Weather conditions were rated better for this survey over last year, adding to the concern. This Grouse Hunter noticed a sharp decline in flushes per mile walked last year with very low apparent recruitment. Others observed the same and indeed the RGS national hunt results in Grand Rapids, MN last fall produced a record low harvest measured in birds per hunter hours and also revealed low recruitment. The 2018 drumming survey affirms these observations. As a suspected contributing factor and wild card, West Nile Virus will get further study this year and we can look for officials to ask Grouse Hunters to provide samples.
More information can be found in this article from the Wi DNR website.
And this article from the Milwaukee Journal Sentinal