Hundreds of double-crested cormorants, American white pelicans and other water birds were discovered dead or dying at two Minnesota lakes early last week. The discovery was made by Minnesota Department of Natural Resources staff who were in the area banding pelicans at Minnesota Lake in Faribault County and Pigeon Lake in Meeker County.

The dead and dying birds were found on islands where pelicans, herons, egrets and gulls traditionally nest. As of Friday, 687 cormorants and 37 pelicans, three ring-billed gulls and one great blue heron had been found dead.

Jeff DiMatteo, a DNR wildlife biologist working with pelicans, said staff saw the same thing happening at both lakes. “We saw dead and dying adult cormorants, with the live ones unable to hold their heads up” at Pigeon Lake, DiMatteo said. “There were old carcasses that would suggest that it has been going on for at least a couple of weeks.”

The U.S. Fish and Wildlife Service in Litchfield is looking at sites in the vicinities of both lakes for any additional die-offs.

Initial tests for avian influenza were negative. The specific cause of the bird illness remains undetermined at this time.

Officials from the Minnesota DNR, U.S. Department of Agriculture and U.S. Fish and Wildlife Service are conducting site clean-ups, and collecting swab and carcass samples for lab analysis. Some early lab results should be available later this week, although it might take longer to determine the exact cause of the bird illness.

While the die-off so far has been detected only in wild water birds at the two locations, wild birds can be a potential source of disease when they come into contact with domestic poultry. For that reason, state animal health officials remind farmers to practice sound biosecurity, including monitoring their poultry flocks for signs of illness and
taking steps to prevent wild birds from having contact with their domestic birds. If birds show sign of sickness, producers should contact their veterinarian or the Minnesota Board of Animal Health at (320) 231-5170.

There are approximately 39 nesting colonies of double-crested cormorants in Minnesota, 87 percent of which occur along with other colonially nesting water birds. Most active nesting sites have a long history of use, being utilized by the birds since the 1960s and 1970s.