One night a few weeks ago I received a concerned call from hiking friend Sandy Knox. She and her husband Rodney had been out in their kayaks, enjoying a serene paddle around a pond near her home. They had entered a marshy area of the pond and spotted a loon on a small mound of earth and vegetation, which they surmised was its nest.

The loon lay in an odd, stretched position, seeming to lean forward over the nest, and it was very still.

“I thought it was dead,” she said. “We didn’t get too close because we know that’s a no-no. What do you think?”

Hmm, this was a puzzle. I knew loons used several different postures and vocalizations to communicate threat or alarm, but this was quite different. I thought it might be a defensive posture.

I found Maine Audubon’s online brochure “Living in Loon Territory,” which described a posture similar to this as one of defense and alarm.

Even though Sandy and her husband thought they were far enough away, I wondered if the loon may still have been reacting to their presence. They can be easily disturbed during the incubation phase and will respond by sliding off the nest, leaving the eggs exposed to the elements and potential predation.

Sandy and her husband made the right decision by erring on the side of caution. They didn’t approach the nest any closer and left the area immediately.

Many times people simply aren’t aware their presence is causing distress for a loon. For example, one of the loon’s famous vocalizations-called a “tremolo,” is also popularly described as its “laugh.” It is one of the calls people love to hear, but it is a sure sign of alarm and means “Stay away!”

Another vocalization is described as a “yodel” and may be given in conjunction with a behavior called a “penguin dance.” The loon appears to stand up in the water and may flap its wings rapidly. Although we may interpret this behavior as pretty and prideful, it is actually another, more aggressive warning: “Stay away – or else!”

Although people in kayaks or canoes are certainly preferable to people roaring by in speedboats or personal watercraft, extreme care should still be taken. When paddlers attempt to get close to loons with young on the water, they may inadvertently separate the young from its parents. If that happens, the babies become extremely vulnerable and will not survive if not found quickly by the adults.

Loons may be having a tough time of it this season. Because they nest so close to the water, all the rain we’ve had may have flooded nests. So enjoy loons from a distance and give them every chance to raise their young successfully.

Maine Audubon’s 22nd annual loon count will take place July 16 this year. It has proven to be a successful tool in monitoring loon populations on lakes and ponds across the state. All are invited to participate; to learn how, contact Susan Gallo at (207) 781-6180 ext. 216, and visit The Loon Project Web site at: http://www.maineaudubon.org/conserve/citsci/loon2.shtml.

NEWS bird columnist Chris Corio can be reached at bdnsports@bangordailynews.net