Loons back on many nests after black flies

Black flies pester a nesting common loon near Tomahawk. (Courtesy: Linda Grenzer)

OCONTO COUNTY - Scientists across the Northwoods hope the second time is the charm. Hundreds of loons are back on the nest after swarms of biting black flies chased many off their breeding grounds earlier this spring.

The latest hatch is racing the clock, so the chicks can grow enough to survive the summer.

Linda Grenzer of Tomahawk says the flies biting nesting loons were the worst she ever saw.

"Very heartbreaking, I actually wanted to go up to him, and take them off him, but I knew I couldn't," she said.

Grenzer is a Loon Ranger, a volunteer for the group LoonWatch. She recorded video of a fly-infested loon in May on Muskellunge Lake near Tomahawk in Lincoln County. That's when Department of Natural Resource scientists say swarms of black flies chased nearly 80 percent of loons off their Northwoods nests.

"The timing of when the black flies were born relative to when the loons are on the nest. They're just hitting the nest so hard that those birds are choosing to abandon the nest," said John Huff, DNR area wildlife supervisor.

But scientists say it was a short-lived swarm. The flies died off after several weeks and now many birds are back on the nest.

"We went back to 20 territories where they had abandonment, their nests in late May, early June. And of the 20 we checked, 19 of them were back on the nests, with a second nest attempt and were incubating eggs," said Mike Meyer, DNR research scientist.

"Oh yeah, they'll wake you up every morning. They start calling back and forth. There's usually just two of them out there," said Bob Ganzel of Oconto County.

Ganzel has been watching loons nest on Munger Lake in Oconto County for decades.

"They're here every year; there are always three of them. This year, we only seen two," said Ganzel.

Scientists say it's common for loons to re-nest.

"They will try again, and hopefully they'll be successful on the second attempt. The big issue is whether or not they get the eggs hatched and the young ones off the nest, and to the state where they can fly south for the winter," said Huff.

Linda Grenzer says persistence paid off for her loons.

"I couldn't believe it; they were back on the nest. One of the eggs did hatch last Wednesday, and I'm pretty happy about that," said Grenzer.

In many areas, chicks have hatched and will stay close to their parents for another couple of months.

The birds will need to grow up quickly. Migration usually begins in October.

According to the group LoonWatch, there are about 4,000 loons in the state. That's nearly double the number 25 years ago.