Rare and protected birds were gunned down on the opening weekend of Victoria's duck hunting season.
The RSPCA's mobile animal hospital went to Lake Burrumbeet on Saturday and treated eight birds scooped up from the wetlands.
The first brought in was a protected red-necked avocet, which was in "severe respiratory distress" and had to be euthanised.
"Its neck and chest were torn open with shot and it was left to die slowly and in terror in the water," RSPCA Victoria's Liz Walker said on Monday.
Anti-hunting campaigner Laurie Levy said six rare and endangered freckled ducks and a swan were among the dead birds collected at the lake.
The rescue team outnumbered the shooters - something that shows duck hunting is a dying sport in Victoria, Mr Levy told AAP on Monday.
"There were so few shooters right around Victoria and it's time for the government to bring it to an end," he said.
The bodies of the birds killed on the opening weekend will be placed outside the premier's office at 10am on Tuesday.