Maine Audubon sponsors the annual Loon Count, organizing volunteers to count loons on Maine’s lakes during the third Saturday of every July. More than a thousand volunteers participate every year. Counters sign up for specific segments of these lakes, and all begin their observations at 7 a.m. in order to avoid the duplication that comes if a loon wanders.
We’ve learned loons reproduce slowly. Although they are long-lived — 20 years or so — their breeding success rate is low. If the population grows at all, it grows slowly. When the count started in 1983, there were about 1,800 loons in Maine. By the 30th year of the count, the population was up to 3,000, though some of the increase may be attributed to an increase in the number of volunteers counting instead of the actual number of loons.
Because they are encountered on most bodies of water, it may seem as though loons are plentiful. They’re not. Loon calls carry a long distance, and just a few loons wailing over the water makes it seem as though an entire lake is full of them.
We’ve learned the population can crash quickly. The number of chicks has not changed much in 32 years, but fluctuations can be alarming. There were 619 chicks counted in 2011. A year later, there were only 178, a sudden 70 percent decline. Loons lay only one or two eggs. Abnormal spring rain can flood nests unexpectedly.
We’ve learned we have been harassing them. Nowadays, people are much more cautious about approaching loons on jet skis and boats. Slowing our boats around nesting loons prevents wakes from washing over the shoreline.
We’ve learned we have been strangling them. Fortunately, we also have learned to dispose of fishing line properly. Discarded monofilament used to entangle too many loons.
We’ve learned we have been poisoning them. In 2002, lead sinkers were banned. More recently, smaller lead jigs were phased out. Yet the larger jigs remain legal. Lost fishing tackle settles to the bottom and mixes with the pebbles that loons ingest into their gizzards for digestion. Lead kills loons very quickly. It’s the leading cause of loon deaths, accounting for one-third of all documented mortalities.
It will take many years before lead poisoning is reduced. Lots of gear is still lying on the lake floor and will remain a threat until ultimately covered in silt. Current gear is grandfathered, and tackle boxes still hold a lot of old lead sinkers and jigs, ready for use. Fortunately, anglers love wildlife as much as anyone, and most already are making the switch to zinc, bismuth and ceramic alternatives.
Acid rain and mercury deposition from coal-fired electricity plants in the Midwest have contributed to habitat degradation in the east. Even declines in water quality contribute to loon mortality, because loons must be able to see their prey underwater. Murky water hurts. Loons have disappeared from Illinois, Indiana, Iowa and Ohio.
We’ve learned that humans are not the only problem. Predators make off with a fair number of chicks. Foxes, skunks, raccoons and minks raid nests. Snapping turtles and northern pike grab babies from below. Eagles grab them from above, much more frequently now that the eagle population has recovered.
The odds are stacked against loon chicks. They are particularly vulnerable while on the nest, so they remain there as short a time as possible — typically one day. Loon chicks can swim and dive almost as soon as they hatch. This comes at a cost. They can’t fly for nearly three months. They don’t learn to fly until autumn, sometimes so late that they risk getting iced in.
By then, they are on their own. Once the chick can forage for itself and avoid predators, it’s on its own. The parents abandon chicks about 12 weeks after hatching. That means the youngsters must learn to fly and discover where to go in winter without any help from mom and dad. Once they find the ocean, they stay there. It takes a loon three years to reach breeding maturity, and most of that will be spent on salt water. They may stay salty longer, because loons are long-lived and tend to retain their mates for life. This leaves few available mates for young loons, and most have to wait six years before they start breeding.
Loons enhance our lives on lakes. We count loons, because loons count.
Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. He developed the Maine Birding Trail, with information at mainebirdingtrail.com. He can be reached at duchesne@midmaine.com.