Thursday, July 25, 2013

On the Lookout for Loons

Freshly rain-washed sunshine sparkled on the lake as a slight breeze ruffled the surface. We couldn’t have asked for better weather. But we sought more than just a lovely pontoon ride on Lake Namakagon. We were on the lookout for loons. By my estimation, loon chicks should have hatched on the lake!  Last year the lake hosted three successful nests, and we enjoyed watching the chicks’ antics throughout the summer.
This year, spring weather posed a bit of a challenge for loons. First, late winter blizzards and cold temperatures kept the lakes frozen much later than normal. Loons migrating north from the Gulf of Mexico had no way of knowing this, and they backed up on ice-free lakes to the south, just waiting for their chance to get back to their old territory or claim a new one. With hormones raging in expectation of mating season, territorial aggression may have caused energy-depleting skirmishes even as loons wait to head north.
As the lakes slowly opened, loons made a break for it, many of them migrating on the night of May 2nd. Unfortunately, an ice storm turned deadly.  Marge Gibson runs the Raptor Education Group (REGI) wildlife rescue center in Antigo. “The loons were iced,” she explained. “They were flying at altitude and the birds became wet, and basically were encased in ice, and then fell to the ground like missiles from a high altitude. Many of them were actually injured.” REGI took in 57 stranded or injured loons in just three days. Most of those were rehabbed and released. Loons not rescued were probably not so lucky. No one really knows the extent of the damage to the loon population.
Finally, the ice on Lake Namakagon went out on Monday, May 13. That Friday I spotted a few territorial pairs who had migrated back to their usual places on the lake. Courtship, pair bonding, nest building and mating can take a few weeks. Then, once the male has chosen the nest site, the female has built the nest, and they’ve copulated on the nest, it takes another couple weeks before the female lays her two eggs.
With only one working ovary, the loon female can only lay one egg at a time, about 1-3 days apart, so the chicks hatch at different times, too. The loon parents share the incubating duties equally for at least 26 days before the first egg hatches. Then it takes about a day for the chicks’ feathers to dry out enough so they can float.
So, by my calculation, today was about the soonest we would expect to see chicks on this lake.
Our first stop on this Loon Pontoon Tour was Sugar Bay. This beautiful, shallow inlet hides behind Anderson Island, and is only accessible by going under a bridge. For the past two years this pair has nested successfully. So it was with great anticipation that we puttered around the nesting bay, and then back into the calm, weedy area the loons use as a nursery.
A dark silhouette of a loon appeared out in the nursery, and we cautiously motored over. Then, another loon appeared near it. As we drew close, it became evident that they were alone. I sighed in disappointment. At this time of year, either the chick should be with the parents, or one parent should still be on the nest. They may still try a second nesting attempt, but laying eggs this late in the season does not give the chick much time to gain strength before it must migrate in November.
With a little disappointment, and a little hope, we turned and headed up to another remote corner of the lake that often hosts a successful nest. Jackson Lake is connected to the main lake by a beautiful, narrow channel filled with water lilies, beavers, great blue herons, and tamaracks. As the view into the wider part of the lake opened before us, we spotted the pair almost immediately. And one loon seemed to have an oddly shaped back…
A crisp view through binoculars revealed a single fluffy chick bumming a ride. Success! The entire crew on the pontoon was elated. Chicks can swim and dive as soon as their feathers are dry, but they tire and chill easily, so catch rides for about their first three weeks of life. This also helps protect them from swimming predators (musky, northern pike, and snapping turtles), and flying predators (eagles and gulls.)
As we watched, the chick slipped into the water, and the parents began to hunt. The adult loon dipped its face into the water; an action called “peering” that allows it to see underneath the surface glare. Then, with submarine-like stealth, it dove. Within a few seconds (the average loon’s dive is only about 45 seconds) the parent popped back up with a minnow cross-wise in its beak. With surprising speed, the tiny chick paddled over to meet the parent, stretched its little neck out long, and gobbled its catered lunch!
At this stage, chicks eat minnows and aquatic insects. Adults (who weigh about 10 pounds)  can eat about 2 pounds per day of smaller fish like perch. Over the summer, a loon family of four will eat about a ton of fish. For reference, a 150 pound human on a winter camping trip eats about 2 pounds of food per day.
We watched for several minutes as the family calmly continued the feeding operation. If any of the loons had given the tremolo alarm call or acted distressed, we would have left immediately. Luckily, loons are learning to be tolerant of humans in boats, and on this lake at least, we rarely cause them to show alarm.
Finally, we had seen enough, and bird-watched our way back to the landing. Spirits soared all around, as we cheered for the loons’ successful hatching, and our successful viewing. Come join me for another Loon Pontoon, held Thursday mornings throughout the summer!
For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, “Deer Camp: A Natural and Cultural History of White-tailed Deer,” opened in May 2013 and will remain open until April, 2014.

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