Middle River, Minn. – Islands in some state lakes, as well as
the entire Agassiz National Wildlife Refuge, are closed until
further notice, the result of birds from those places testing
positive for virulent Newcastle’s disease.
The virus has killed more than 1,200 double-crested cormorants,
and, to a lesser extent, American white pelicans and ring-billed
gulls also are affected.
The virus has been confirmed at Minnesota Lake, Pigeon Lake,
Lake of the Woods, Marsh Lake, Lake Kabetogama, and Lake
Mille_Lacs. Birds also have been submitted from Leech Lake, but
those test results aren’t available yet, said Erika Butler, a DNR
A pelican that was found dead at Agassiz NWR has tested
positive, another couple have been sent in for testing, and “we do
have a few birds that are swimming around and acting weird,” said
John Braastad, the assistant manager at Agassiz.
There won’t be any closures at Voyageurs National Park.
“Voyageurs National Park staff, after consulting with wildlife
health officials from various state and federal agencies, have made
the decision to not close access to the colony on Lake Kabetogama
because of the limited risk to humans,” according to a Park Service
news release. “The island supporting the cormorant colony is a
small rock outcrop with no trees that receives almost no visitation
by park visitors because of the often strong smell produced by the
bird species present on the island.”
Newcastle’s disease hasn’t affected game species like mallards
or other ducks, and isn’t a major concern for humans, though it may
cause mild conjunctivitis and flu-like symptoms. Signs of the
disease in birds include drooping heads and paralyzed wings and
Nestlings and juvenile birds are most commonly affected, and
mortality rates in wild species can vary greatly.
The virulent form of Newcastle’s disease also can be highly
infectious to domestic poultry and can cause high mortality rates
in unvaccinated birds, according to a press release from
“The big concern is if it gets off the refuge,” Braastad said.
“It is fatal to domestic flocks of poultry and captive birds. It’s
a safety factor for the poultry.”
Aside from the refuge, specific islands have been closed, as
officials don’t want hunters or others to be on the islands where
the birds nest.
“They are really well signed off and it shouldn’t be a mystery
if you’re out there looking at them,” Butler said. “Anyone fishing
or doing anything like that won’t be impacted or affected.”
The disease can be transmitted on contaminated equipment and
clothing, and infected birds can transmit it directly, or via their
feces and excretions.
Waterfowl hunters, especially, should take precautions around
areas where the disease has been found, wildlife officials say.
“If people do go out in the water and handle waterfowl, keep in
mind to keep things clean,” Braastad said. “Wash their hands and
the area (where) they have cleaned the waterfowl. The waterfowl can
be a carrier, so they should handle their waterfowl carefully, and
clean themselves and all their equipment. It’s to their advantage
to keep things clean.”
The first time there was an outbreak of Newcastle’s disease in
the United States or Canada was 1990, and in 1992 more than 35,000
cormorants died from the disease across the Great Lakes, Upper
Midwest, and Canada. That year was the last time it was documented
in Minnesota, Butler said.
Closures at Agassiz
The discovery of Newcastle’s disease at Agassiz, in addition to
forcing closure of the refuge, also has led to the cancellation of
a public duck-banding event that was scheduled for Saturday, Sept.
20; closure of the Lost Bay Habitat Drive; and cancellation of
school-group duck banding this fall.