Where did the loons go?

loon

We usually have two or three loons on our lake all summer long. Last year, we did not see or hear any, but we had a pair of eagles and a huge great blue heron. Could that be the reason we were missing the loons?
—Lynne McIndoe Meredith, Spar Lake, Ont.

Probably not. A heron wouldn’t bother the loons, and while eagles will sometimes predate a loon nest, their presence alone wouldn’t cause your friends to go MIA. So what happened to these regulars? Nothing bad, necessarily, and it depends on whether the loons were paired or singles, says Tiffany Grade, a staff biologist with the Loon Preservation Committee in Moultonborough, NH. Single loons—young and, we assume, restless—tend to drift around, visiting different lakes, before finding one where they will ultimately establish a territory. Your loons may have simply picked another spot in which to settle down. A loon pair, on the other hand, may have nested somewhere hidden, or at a different end of the lake, according to Kathy Jones, the volunteer coordinator for the Canadian Lakes Loon Survey with Bird Studies Canada. Or, if they’d tried but failed to start a family, you might have missed Ma and Pa. “If loons don’t breed successfully, they may leave the lake early.”

Humans are the animals most likely to drive loons away, says Jones. Lots of human activity—new cottage builds, PWCs and other powerboats zipping around, fishing (lead fishing gear can be toxic to a loon if ingested)—is dangerous and disruptive. “If the nest site is constantly being disturbed, the loons might abandon the lake.”

And who can blame them? If our neighbourhood became crowded and noisy, and our friends were continually poisoned by lead, we’d move too.