Approximately 200 gulls were found dead in Milwaukee this week, reported the Humane Society.
They said the birds likely died from the heat or from dehydration.
The hot, dry weather has also caused several fish kills, like the one in the La Crosse River Marsh, according to state Department of Natural Resources officials. Dead fish are lining the shore.
DNR officials said the falling water levels are leaving less oxygen for the fish. In addition, the water temperature has been on the rise.