NWA 6/28/13

A Northwoods Almanac for 6/28 – 7/11/13 by John Bates

Cecropia Moths

Wil Conway and Addie Hoffman recently sent me beautiful photos of adult Cecropia moths (Cecropia hyalophora), the largest species of moth in North America. Wil’s cecropia was “a hanger-on [a screen door] at my friends hot-dog stand, the Bunn-runner, on the corner of Hwy. 47 and Co. H, outside Lac du Flambeau.” Cecropias belong to the family Saturnidae, the Giant Silkworm Moths, of which some are indeed giants, with wingspans measuring up to 6 inches wide.

The Saturnids, include the Cecropia, Prometheus, Polyphemus, and the Luna moths, which for Greekophiles like our youngest daughter gets them all worked up. Prometheus is credited with the creation of man from clay and the theft of fire for human use, an act that earned him the rage of Zeus who sentenced him to be bound to a rock, where each day an eagle,  the emblem of Zeus, was sent to feed on his liver.

Cecrops was the founder and the first king of Athens. He taught the Athenians reading and writing, marriage, and ceremonial burial, and was said to have been the first to deify Zeus, and to set up altars and statues of the gods. The Acropolis became known as the Cecropia in his honor, and the Athenians are said to have called themselves Cecropidae, during the reigns of the five following kings, in his honor.

And you may recall Polyphemus, the Cyclops in Homer’s Odyssey, who Odysseus eventually blinds in order to escape his island.

Who knew these moths had such classical connections?

Anyhow, the Saturnids (I bet you knew Saturn was the Roman God of Agriculture) are distantly related to the Chinese moth that is used in silk production. North American silk moths aren’t used to make silk, but as yet another in a long line of stories of imported species gone amuck, the horrifically invasive gypsy moth, in the tussock moth family, was originally imported to test its feasibility as a silk producer.

A Cecropia caterpillar starts off tiny and black, proceeds to eat a wide variety of tree leaves, and grows up to be the size of your thumb, pale green, with Technicolor knobs that have earned it the nickname “The Christmas Lights Caterpillar.”

In June, the females emit pheromones, air-borne odors that the males, using their large, feathery antennae, can detect in minuscule concentrations up to several miles away, a period referred to as their "calling time." Calling time for Cecropia moths is from 3:00 AM until sunrise. Since adult silk moths in North America have greatly reduced mouthparts, so much so that can’t feed, they only live two to four days, just long enough to hear that calling, mate, spin a cocoon, and die.

Pelicans on Trout Lake

Bill and Sue Fehlandt reported seeing a flock of 50 white pelicans on the north end of Trout Lake on June 18. We usually see a flock or two in migration every spring, but wandering flocks in June of unmated juveniles (pelicans don’t breed until they’re three years old) rarely appear in our area.

This is changing, however, and in a big way. While white pelican sightings in the Northwoods are still quite uncommon, white pelican nestings in Wisconsin are way up from the rarity that they were 20 years ago. Nesting pairs during the 2011 breeding season topped 3,000, including 1,263 nests on Butte des Morts, 1,603 nests on three islands in Green Bay, and 159 nests on two islands in Lake Winnebago. They also nested at Horicon Marsh before high water forced them off the refuge, though they still use the area for rest and relaxation, a behavior called "loafing" by biologists (and one lots of humans employ on water as well). It’s a fait accompli that they will eventually be nesting, if they aren’t already, along the Wisconsin side of the Mississippi River, from Alma south to Dubuque, Iowa.

The colonies can get massive. The largest North American colony, in Minnesota, is now attributed to the islands of Marsh Lake, a 4,400-acre body of water about 150 miles west of Minneapolis, where the peak count, in 2006, was 38,872 breeding birds.

Adult white pelicans are the cargo planes of the avian world, weighing 16 pounds with a very impressive 9-foot wing span, the second largest wingspan of all North American birds – only the California condor eclipses them. Despite their size, they’re a graceful flier, either singly, in flight formations, or soaring on thermals in flocks.

They’re also skilled swimmers, but they don’t plunge-dive for prey like their coastal relatives, the brown pelican. Instead, they make shallow dives from the surface of the water or just plunge their heads underwater. They often form a circle or semi-circle and, using coordinated bill dipping and wing beating, drive prey toward shore where it is more easily caught. Gizzard shad and emerald shiners seem to be the fish they most readily take, but they’re opportunistic feeders and will eat anything. Before anglers get worried about the pelican’s impact on “their” fish, however, there’s little evidence of white pelicans taking any significant numbers of game fish.

They nest close together in colonies on undisturbed islands and peninsulas that aren’t subject to regular flooding, laying their eggs on bare gravel, sand, or soil with little vegetation.

Historically, the earliest known report of white pelicans in Wisconsin was made by a French explorer, Pierre Radisson, in 1655. White pelicans are believed to have been part of the Green Bay landscape in the 1700s and 1800s. Evidence is inconclusive about precisely when they disappeared, or why. But they returned in the mid-1990s and have been growing in numbers ever since.

In the Northwoods, it's likely that pelicans once nested on an island in Pelican Lake, southeast of Rhinelander in Oneida County.

Nationally, white pelican numbers have been increasing steadily at a rate of about 3.9 percent per year from 1980 to 2003, so they’re very much a success story. Will they be nesting sometime soon in the Northwoods? I’d be willing to bet they’ll be nesting on an island in the Turtle-Flambeau or Chippewa Flowage within a decade.

Moon and Alma Lakes Shoreline Restoration

Several weeks ago I spoke at the annual meeting of the Moon and Alma Lake District near St. Germain, and my takeaway was how engaged and committed these folks are to their lakes. They’ve invested a ton of both intellectual study and sweat equity, and it shows. For me, the highlight of their many efforts is their shoreline restoration project. During the spring and summer of 2009, 1,300 linear feet of shoreline of Moon Beach Camp on Moon Lake underwent  an “extreme makeover” when native trees, shrubs and herbaceous species were planted to restore the shoreline.

The restoration was a cooperative effort between the WDNR, the Vilas County Land and Water Conservations Department, the Alma Moon Lake Protection and Rehabilitation District, and Moon Beach Camp. They planted 184 trees of 16 species, 1558 shrubs of 23 species, 21 vines of two species, and 9684 forbs and grasses of 89 species, all within a 35-foot buffer zone along the quarter-mile of lakeshore. The shrubs and trees included fruiting species loved by birds like serviceberry, choke cherry, mountain ash, American plum, chokeberry, gray and red-osier dogwood, elderberry, snowberry, blueberry, and winterberry.

They also controlled erosion along the steep banks by utilizing a bio-engineered retaining wall and coconut erosion control blankets. And they had the foresight to construct 3,000 linear feet of eight-foot-tall nylon mesh fencing around the entire area to keep the rabbits and deer out. 

A before and after impact study was implemented, including bird, small mammal, and carnivore surveys, to contrast the impact of the restoration.

For the whole story, see http://almamoonlake.org/assets/files/Alma-Moon_Management_Plan_2012.pdf , but suffice it to say, they did work that could, and should, be modeled by individuals and lake association to fit their unique settings. This project represents what can be accomplished when lake property owners work with the DNR, county, and private organizations through a shared vision of stewardship.

Dogwoods in Flower

We boast 6 species of native dogwoods in the Northwoods, and I believe all are in flower right now. Red-osier (Cornus stolinifera), gray (C. racemosa ), alternate-leaved (C. alternifolia), round-leaved (C. rugosa), silky (C. amonum), and the diminutive bunchberry (C. canadensis) comprise our natives, and all provide a bounty of berries for birds. If you’re looking to plant a large shrub/small tree that attracts wildlife, you can’t go wrong with any of our native dogwoods.

Brown Thrasher – North America’s Best Songster

A brown thrasher has appeared off and on this June beneath one of our feeders, a visitation that we are celebrating. Brown thrashers are relatively uncommon in the forested Northwoods, preferring edges and shrubs and fields more than woodlands. We rarely see them and get pretty worked up when we do because they are the virtuosos of all birds on Earth, which is a very large statement indeed. In the book The Singing Life of Birds, avian researcher Donald E. Kroodsma describes a brown thrasher that in one recorded two-hour session sang 4,654 songs, 1,800 of them different (many mimicking the songs of other species). Kroodsma estimates that the brown thrasher is capable of singing 3,000 distinctive songs, which makes on wonder since birds hear four times better than humans, what are they hearing?           

And what are they saying? They repeat their phrases usually twice, so one version of the thrasher song is given by a Mrs. H. P. Cook as one end of a telephone conversation, "Hello, hello, yes, yes, yes, Who is this? Who is this? Well, well, well, I should say, I should say, How's that? How's That? I don't know, I don't know, What did you say? What did you say? Certainly, Certainly, Well, well, well, Not that I know of, Not that I know of, Tomorrow? Tomorrow? I guess so, I guess so, All right, All right, Goodbye, Goodbye."

John Burroughs wrote about this evasive songster in Fresh Fields, “There is no bird so afraid of being seen, or fonder of being heard.”

We listen for it every morning, but so far we’ve only heard it once. Perhaps it is nesting a little ways away in a more open area, its song just out of our limited hearing. We’re just glad there’s even a chance of hearing it.

Last Hurrah for Intense Bird Song

            Bird song typically quiets down dramatically in July, so if you haven’t filled up your heart and mind with enough of their beauty, you only have a little time to do so. To be sure, some will still sing throughout the summer, but by July the time for defending territories and attracting mates has passed by. Get out early (dawn is the best!) and enjoy them while you can.

Eastern Gray Treefrogs Din

            While the birds may be quieting down, the Eastern gray tree frogs are still continuing their evening noise-a-thons. Their staccato blasts are loud, short, emphatic, and not in the least harmonious. But then I’m not a female gray treefrog, so what do I know? Perhaps these males are all Pavarottis and my limited interpretive skill does them no justice.

They, like the birds, should soon be quieting down, so enjoy their “music” at its peak right now.