Wisconsin's first confirmed cases of West Nile virus in ruffed grouse were reported Tuesday by the state Department of Natural Resources.
The DNR
said that West Nile was confirmed in three of 16 grouse tested so far.
The DNR said the results are still preliminary because another 238
grouse samples remain to be tested.
The agency is testing
both sickly grouse that were turned in to wildlife officials and grouse
blood samples submitted by hunter volunteers in the field.
Wildlife
researchers are concerned that West Nile virus may be one factor
leading to an unusually rapid and steep decline in grouse numbers in
recent years. Researchers in Wisconsin, Minnesota and Michigan this
winter are testing hundreds of grouse samples obtained by hunters from
birds shot last fall to see how prevalent the disease is in the popular
game bird.
Michigan already had five positive West Nile
hits in 2018 and officials in Pennsylvania say West Nile may already be a
big enough factor there to spur grouse population declines, especially
in areas where the bird is already stressed by poor habitat conditions.
After
the Pennsylvania study showed problems, wildlife managers in Minnesota,
Wisconsin and Michigan began to wonder if the recent, sharp downturn in
grouse numbers in the Midwest may be related to the virus, leading to
the region-wide testing effort last fall. Minnesota grouse drumming was
down 29 percent in 2018 from 2017.
Charlotte Roy, grouse
project leader for the Minnesota DNR, said her agency has not yet
received any results from Minnesota grouse tested for West Nile. She
expects the first results by March.
