Loons Abandon Nests Facing Droves of Black Flies

Jun 4, 2014

As many of us in the Northwoods are being driven crazy by mosquitoes, loons are being harassed by blackflies. 

Loons in the Northwoods are suffering due to high numbers of black flies pestering them while they try to nest.
Credit Mitch Mode

High numbers of loons are having trouble staying on their nests this year due to a surge in a certain kind of black fly that only targets loons.  

Walter Piper, a researcher from Chapman University who has been studying loons in the Northwoods for twenty two years, says it’s the most abandoned nests he’s ever seen.  WXPR’s Natalie Jablonski spoke with Piper about what that means for the loon population.

Hundreds of flies may swarm a single loon, causing the bird to flee its nest. Piper says it's painful to see the birds being attacked by the flies.  

“In a typical year, we get anywhere from 5 to 30 percent of first nests that get abandoned because they occur at a time when blackflies are very abundant.  This year it’s been almost 70 percent.  So it’s been the highest in the 22 years that I’ve been following them.” 

A surge in blackflies doesn’t always coincide with loons’ nesting time…but this year it did.  Piper says in a week or two, the loons will try again to nest in a new location or even in the same place.  The blackflies should have died down by then. 

But Piper says it will have an impact on the loons’ reproductive success this year. 

“This sets them back.  It means the chicks are going to hatch later, and that somewhat reduces the likelihood of the chicks surviving.  It also means they’ve spent their first attempt at a nest to blackflies, and so it reduces the chance of them raising and fledging chicks.” 

Piper says loons already face a variety of hurdles like poisoning from lead tackle and losing eggs to raccoons and other predators.    

Piper’s research team has more updates on loons at loonproject.org.