The Log in the Lake
In slow-breaking news, a tree fell into a bay 20 years ago. The story is still developing.
I remember when it was still standing: a stately white pine at least 60 feet tall. On this hillside, overlooking a lake near my home in Carlton County, it had surely lived a long, strong life with plenty of moisture and sunlight.
I never saw it until after its life was over, but still the tree stood tall even in death. Its thick branches were perching sites for several birds that visited the lake. I enjoyed great views of bald eagles, ospreys, cormorants, and herons as they rested above the water.
Then came the day that I knew would arrive. Its trunk aged and decaying, the tree came crashing down. In many places, a fallen tree means less or no viewing of local wildlife. But not so for this late, great white pine. As fate would have it, the tree splashed into a bay of the nearby lake and not the other way, into the woods. Now a massive log, floating on the water surface, projected out 50 feet from the previously empty shoreline. A new chapter of nature watching was just beginning.
During the next several years, this log was discovered by a large and varied group of local critters. Birds made frequent use of the log, though they were not the same ones that landed on the tree when it was standing. I saw ducks, mergansers, geese, sandpipers, and kingfishers alight on the prostrate main trunk as they fed and rested. Swallows, phoebes, blackbirds, warblers, catbirds, vireos, and thrushes all came by to perch in the tree’s remaining branches and snatch insects from near the water.
One year, an Eastern kingbird built a nest on the branches. On a May day, as a chilly east wind hit, several species of swallows used this bay as a protection from the breeze as they fed, pausing on the branches of the log. Another May morning, I stood in awe to watch a warbler wave of 15 species moving about and frequently landing on this downed tree.
The greatest crowds were composed of turtles. Painted turtles are common in northland lakes, and this lake was no exception. These turtles spend winter under water nearly dormant in a slowed-down phase. With the spring ice-out, they return to the life that we know of them. And a very necessary part of this life is to climb up on an exposed surface, usually a log, to bask in the sunlight. This apparent inactivity is important to the turtles. It raises their body temperature and helps them make vitamins and rid themselves of external parasites.
One recent year, the ice didn’t go out on this lake until May 11, but by May 14, turtles were basking on the log. Word spread quickly among these aquatic reptiles, and by late in the month, the log was crowded with more than 70 painted turtles, far more than the typical 20 to 30. As I looked over this scene of shelled bodies in every available space, even on each other, I noticed a much larger snapping turtle wanting to warm up. It too climbed up on the log. These warming rituals, common in May and June, slow down once the air and water temperatures rise.
As the summer warms, other daily changes can be seen. In June, along the shore, dragonflies climb up from their aquatic youth to begin their adult life of flight. The log has annually been the site of emerging chalk-fronted corporals in early summer. Arriving in the early morning, I often find the exuviae—the cast-off skins—of the insects that made this rite of passage at night. For the next few weeks, these white-patched dragonflies will be seen around the log and other shoreline sites as they feed and bask. Progressing through the warm months, calico pennants and four-spotted skimmers appear here, along with a few gomphids and darners. Late in the summer, smaller red meadowhawks take over the site. Here too are damselflies—dragonfly cousins: bluets and spreadwings—during the days of July and August.
The breezes of summer warm the lake’s surface but also cause disturbances that affect insects that live in this unique habitat. Many times, when looking at the log on windy days, I have seen whirligig beetles and water striders taking shelter from the breeze near the log. On calm mornings, the area around the log is often filled with shed skins of the aquatic insects—caddisflies, mayflies, and midges—that emerged from their immature stage during the night.
Where there are insects, there are spiders. A regular phenomenon on the branches of this floating log are the large webs of long-jawed orb weavers. Many times, while viewing the bay at dusk, I note these crafters constructing their snares. And when I paddle past them in the calm at dawn, I see these webs holding prey of nocturnal insects. One summer day, I also found a funnel web on the log. It is not only the web-makers that hunt here. I’ve observed large fishing spiders too, both on the log and on the water surface nearby.
Being out in the open, with plenty of sunlight and moisture, the log served as a great site for plants to grow. While the dead tree was still standing, lichens and mosses thrived upon it. After coming down with the tree, they continued to grow and were joined by other greenery.
During the years that the long log floated in the bay, many flowering plants found it as an agreeable location to grow. As the seasons unfolded, I spied the leaves and small white flowers of water horehound, the yellow clusters of tufted loosestrife, and the tiny plants of dwarf St. Johnswort all growing here. Later in the season, I saw white water smartweed and bulb-bearing water hemlock taking root and flowering on the log. Even a couple of woody plants were able to grow here. A single white birch lasted for a few years, while a growth of leatherleaf thrived on the log, with green leaves all summer turning red in fall.
But it was the thick growth of roundleaf sundew, a small insectivorous plant, that kept me coming back to look each season.
On the log, these plants with sticky oval leaves found enough insect meals to thrive. Many July mornings, I ventured to the log to see their tiny white flowers as they opened at the end of long, curled stalks. I returned in fall to look at the seeds they produced.
In the shallows calmed by the log lying in the bay, both the yellow pond lily and the white water-lily produce their floating leaves and long-lasting flowers. The large leaves lying on the surface attract plenty of insects.
Freeze up for this bay is usually in late November, and as the ice builds up around the log, more critters come by, their presence told by their marks in the snow. Deer, foxes, coyotes, raccoons, and otters have visited. The traffic slows a bit in midwinter but continues throughout the cold season, leading to another spring and ice-out.
The tree died more than 20 years ago, but its presence has added a great deal to the life of the bay—and to my life. On my regular visits I always look at the log to discover what is happening. And I’m not disappointed; there is always more to see.