A Northwoods Almanac for July 15-28, 2011
Aquatic Flowers
Mid-July typically marks the beginning of spectacular aquatic wildflower displays that last well into August. A number of aquatic flowers have already come and gone, but it’s now that our lakes and rivers reach their height of flowering diversity and abundance. A shallow lake clothed in water lilies and pickerelweed simply soothes the soul. We could eliminate a lot of societal stress if folks would slowly paddle a canoe along the shoreline of one of our lakes rimmed in full flowerful regalia.
Trying to learn all the flowers can take time, so if I had to recommend five to be sure to know, my list would include these most common and showy flowers: white water lily, pickerelweed, blue flag iris, marsh milkweed, and Joe-pye weed. I’ve included pictures of a few of them, but if you want to learn your aquatic and shoreline plants, here are the best resources for our region:
Through the Looking Glass by Borman, Korth, and Temte
Aquatic Plants of Wisconsin by Skawinski
Wetland Plants and Plant Communities of Minnesota and Wisconsin by the US Army Corps of Engineers
A Great Lakes Wetland Flora by Chadde
Sightings – Red-Headed Woodpeckers
Lisa DeHorn has had a red headed woodpecker visiting her suet feeders in Hazelhurst since Memorial Day weekend. She notes, “I've not seen one on our property before nor up in the Minocqua area in the last 14 years of visiting regularly. I'm wondering if this is a fluke or if we may be honored with their presence regularly in the future. Used to see them a lot in Adams county in my youth, but they've become a rare sight. The hairy woodpeckers are not happy about the new visitor/resident.”
Lisa also has had red-bellied woodpeckers nesting over the last three years on her 10 acres. Here’s how she describes her property: “Our 10 acres is a very mixed forest of pine, oak, maple with aspen and birch phasing out. We don't cut the understory back so the birds have hazelnut and viburnums. Our property abuts a 97-acre parcel that is also managed very naturally with plenty of snags.”
Because of their management approach, the DeHorn’s have seven species of woodpeckers utilizing their woodlands: pileateds, hairies, downies, yellow-bellied sapsuckers, red-bellied woodpeckers, northern flickers, and now the red-headed woodpeckers.
A last note on why red-headed woodpeckers have become so uncommon, this from Wisconsin’s All-Bird Conservation Plan: “This species is in decline over its entire range. There has been a 50-55% decline nationwide, and approximately 60-70% in Wisconsin. The most recent Breeding Bird Survey data corroborate these findings, indicating significant declines range-wide and within Wisconsin.
“Loss of snags, fire suppression, firewood harvest, ecological succession of open woodlands to closed-canopy woodlands, and vehicle-caused mortality are all significant issues, as is interference competition with the European Starling. Invasive shrubs, such as buckthorn, may degrade existing habitat and also pose a threat to Red-headed Woodpeckers.”
Swimmer’s Itch
Mary, Callie, Mary’s sister Nancy, and I all took a lovely swim in the Manitowish Chain of Lakes on a very hot July 1, and an hour later we were itching like crazy with “swimmer’s itch,” the first time (and hopefully the last time) any of us have ever gotten this malady.
Technically known as schistosome dermatitis, swimmer’s itch appears as red itching, bite-like welts. The organism that causes swimmer’s itch is an immature life stage of a microscopic flatworm. Its complicated life history begins as an adult in the blood of infected ducks, geese, gulls, swans, muskrats, beavers, and other water-based organisms. The flatworm produces eggs that are eventually passed through the feces of the animal. If the eggs land on water, they release small, free-swimming larvae that search out certain species of aquatic snails. The infected snails eventually release a more developed form of the larvae, which then swim in search of a bird or mammal so they can start their lifecycle over again.
The problem arises for humans when the microscopic larvae mistake us for the appropriate bird or host mammal, burrow into our skin, and cause an allergic reaction and rash. The good news is that they die quickly because they can’t develop inside a human. The bad news is that the leave inflamed welts that cause a lot of itching for nearly a week.
Since the larvae are most common in shallow water by shorelines, prevention options exist. Given that the organism starts out most commonly in the stomach lining of ducks, if you are currently feeding waterfowl, stop!
And if ducks like to loaf on your dock, try to move them on. These actions will not only reduce the chances of the parasites being released in your swim area, they will also help keep the waterfowl wild, rather than semi-domesticated, which is worthwhile in itself.
A second strategy is to swim in deeper water away from shore where you’re less likely to come into contact with the shoreline-loving flatworms.
The third strategy is to immediately dry off or take a shower after getting out of the water, which helps prevent the larvae from finding refuge on your skin. They only burrow in once the water starts to dry on your skin.
Only about one-third of the human population is apparently sensitive to the infection, so your family or neighbors may not be bothered one bit, while you may be a very unhappy camper. Swimmer’s itch isn’t contagious, so can’t be spread from one person to another.
Please note that the presence of ducks and/or snails does not mean that the flatworms are present! Some of the clearest recreational waters in the state experience swimmer’s itch annually, whereas other lakes may have an occasional outbreak or none at all. Wind and currents may also carry the larvae up to four miles from the release area. So, before any of us panic and go out and try to eliminate every snail we see, please recall that snails are beneficial organisms that feed by scraping algae off of rocks, sand, and plant stems, thus helping to clean water. And snails are also eaten by a host of organisms, including many fish species that folks work awfully hard to catch.
Currently, 58 species of snails live in the waters of the Great Lakes region, and swimmer’s itch is really quite uncommon. In the scheme of things, swimmer’s itch is little more than a nuisance to humans, and by taking proper precautions, most folks will never even encounter it.
Celestial Events
The full moon occurs tonight, July 15.
The warmest days of a Northwoods year occur between July 17 and August 2nd, with an average high of 80° and a low of 57°. July 24 is statistically the hottest day of the year in the U.S., and presumably in the Northwoods as well. Lake temperatures typically reach their highest in the last week of July – Lake Katherine in Hazelhurst reaches it’s warmest average temperature, 76°, on July 25 and 26, according to Woody Hagge’s 38 years of data.
Poisoned Eagles Treated and Released
On June 1, seven bald eagles were released back in the wild nearly two months after they had ingested a deadly poison at an Eagle River landfill. Marge Gibson and her staff at Antigo’s Raptor Education Group treated the eagles non-stop after they had rescued them on April 9. The eagles had been accidentally poisoned in what is the largest documented mass poisoning event of its type in U.S. history. Initially there were eight eagles at the site, but one flew away and was later found dead.
Unfortunately, details of the poisoning cannot be released because the case remains under Federal investigation.
The Raptor Education Group does exceptional work, as evidenced by this event. See their website at www.raptoreducationgroup.org for how to visit their facility or to donate to their efforts.
Black Terns
A small colony of black terns has again nested on Powell Marsh, and is easily seen by walking out on the dike at the main overlook to the “T” intersection. The birds are noisy and not in the least afraid of humans, so they often fly back and forth right overhead.
Historically, black terns were widespread in Wisconsin and regarded as a common breeding species. Today, they are concentrated in east-central, southcentral, and southeastern Wisconsin, and their population shows a long-term decline. One reason for their decline is the simple loss of wetlands. Prior to Euro-American settlement, wetlands occupied an estimated ten million acres of the total 35 million acres of Wisconsin’s land area. Today, only 53% of these wetland habitats remain.
Their decline may also be due to human disturbance, reproductive failure due to predation, adverse weather or water level fluctuations, and loss of winter and migratory habitat, so there’s no smoking gun. Because of their decline, black terns are listed as a species of Special Concern species in Wisconsin.
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