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The corn and wild grasses have begun to turn brown and even a few trees were beginning to show signs of color last week, hinting of the full palette we will see in October. As much as I love summer and its richness of life, something about the seasonal transition that has begun brings an air of excitement that is really special.
Birds on the move
One of the most interesting phenomena to observe in the next few weeks, besides the obvious changes in the vegetation, will be the migration of birds. Many were already grouping and moving about last week along the rivers and woods. I saw cedar waxwings grouping up and acting like flycatchers, dancing after insects in the air over a Black River slough.
Mark Anderson, Wisconsin Department of Natural Resources Mississippi River biologist told me last week that some preliminary teal, widgeon and other ducks along with a few adventurous pelicans were also beginning to move south along the river.
While visiting Black Hawk Park south of Genoa recently, I heard the familiar sound of dozens of grackles gurgling and squawking in a large tree. That is a sure sound of approaching fall if I ever heard one.
The coming season is a very popular time for birders since it gives them a chance to see many species that are only seen during the spring and fall migrations. The trick will be to be at the right place at the right time to catch the ephemeral appearances made by these seasonal visitors.
Cormorants
Eric Nelson, U.S. Fish & Wildlife Service Biologist with Upper Mississippi River Wildlife and Fish Refuge said another interesting but less well-known waterbird is beginning to move into the Coulee Region area — the double-crested cormorant.
Last week, Nelson saw more than 100 of them roosting in trees along a Mississippi River backwater near Winona, Minn. The dark, two-foot long duck-like birds roost in trees at night and disperse to feed on fish during the day.
Their feathers are not as water repellent as those of ducks, so they float deeper in the water, and frequently spread their wings to dry after diving. They are fun to watch as they seek schools of fish and dive to feed on them, often in concert with pelicans and gulls. In fact, they are so efficient at fishing that anglers are sometimes concerned about their predation on gamefish.
Around Lake Superior’s Apostle Islands on Lake Superior and around Green Bay the cormorants are so numerous that they have been blamed for reductions in the perch populations. They also kill vegetation on the islands where they concentrate to breed and roost.
Ironically, though the birds were in danger of extinction in the 1970s, efforts are now being taken to lower the numbers of cormorants in especially hard hit areas around the Great Lakes.
Nelson said we do not seem to have as big a potential for problems around here. Only a few dozen cormorants live and breed in the area and a somewhat larger population breeds on the Mississippi River in Iowa waters. Several thousand cormorants will pass through during a typical fall.
Some anglers might resent the fact that they eat bluegills while migrating through, and no doubt they do, but they also consume a lot of the very abundant gizzard shad along the river. No studies have been done on the impact of the cormorants on the refuge but Nelson has heard of no indication of any serious problems to the local fishery.
Superhydrophobic lotus leaves
While in Black Hawk Park, I saw the American lotus had bloomed in abundance in the bay on the south end of the park. A few were still in full blossom but a lot of the cone-shaped seed pods stood naked on their stems, many with a ring of discarded petals lying below.
Because of the low water level on the Mississippi, I could walk up to some lotus plants on the exposed bottom near the shoreline. I wanted to check out a famous quality of the lotus leaves: superhydrophobicity. That’s a very big word meaning that water is “afraid” of the leaf’s surface.
The leaves are, in other words, super water repellent. When a drop of water lands on the pad, it beads up almost perfectly, rolling off easily and taking dirt with it.
That is a quality that has obvious advantages for us as well, and scientists have long sought a way to duplicate it. In 1997, it was discovered that the apparent waxy surface actually gained its water repellency by millions of extremely tiny bumps on the surface that supported the water drop without breaking its surface tension — like the so called “bed of nails” that support East Indian magicians without puncturing their skin.
Breakthroughs have already been made, and once a feasible process for making a substance that can be easily applied to surfaces, we can expect things like super windshield repellents and de-icers, life-saving coatings for airplane wings and perhaps even really free-flowing catsup bottles.
Like the butterfly proboscis that predated the drinking straw, nature has beaten us again with the marvelously superhydrophobic lotus leaf.
Whaditiz
It was a jewelweed plant. I saw huge clumps of it growing in places along Highway 26 from Lansing, Iowa, to La Crescent, Minn.
Contact Jim Solberg at (608) 782-2560 or nitefrogger@charter.net.
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