A Northwoods Almanac for May 28 – June 10, 2010
Raven Nest
Mary, Callie, and I spent last week exploring the beautiful Grand Marais area of Minnesota’s North Shore, and one of the many highlights of our trip was our discovery of a raven’s nest on a vertical cliff face of the Kadunce River. We wouldn’t have seen the nest if the three chicks hadn’t been making such a racket that we were drawn to it. The cliff face was literally straight down – we were unable to actually see the river below given the narrowness of the gorge – with the large stick nest hanging precariously on a tiny shelf.
I’m not privy to raven nesting data for Minnesota, but observers for the Wisconsin breeding bird atlas found 34 active nest sites in Wisconsin, “but none with eggs, which is due most likely to a combination of winter/early spring nesting and deep snows that make access to nest trees or cliffs difficult.” In other studies, eggs have been found in raven nests in Wisconsin as early as February 16. The atlas observers did report 15 nests with young in them as early as March 16 and as late as June 17. Fledglings were seen as early as April 10 and as late as August 14, illustrating the wide variation in nesting times that ravens are known for.
Ravens are said to mate for life, but no long-term studies have been done to clearly support the contention. Ravens typically lay 3 – 7 eggs, incubate them for 18 – 21 days, with the young fledging 38 – 44 days later. The female does most of the incubation of the young, but lest you think poorly of the male, he often stands guard while the female incubates, feeds her, and may incubate the eggs in cold, stormy weather when the female may have to leave the nest to feed.
The young were described by one researcher in 1945 as looking like “grotesque gargoyles,” but not to us. We had never seen a raven nest before, and we were thrilled to find it.
Northern Parula Warbler and Usnea Lichen
We also heard and saw many northern parula warblers along our various hikes, and while we didn’t see any of their nests, we frequently saw the material they use to make their nests, a hanging lichen (Usnea) commonly called old man’s beard moss. The female parula builds her nest within the hanging masses of the lichen, weaving the stringy material into a cup at the bottom with an entrance hole in the side of the mass. In studies of the parula’s nest building, one female carried 221 loads of materials to the nest site, while at another nest, a female carried 206 loads to the nest. In both cases, the male did not assist the female, but he did accompany her on about half the trips, I suppose giving her positive encouragement on the good work she was doing.
Interestingly, the nest may be used in successive seasons; one nest in Maine was used for four successive seasons. This is quite unusual for songbirds, which rarely reuse their nests.
Beyond that, surprisingly little is known of their breeding behavior. The penultimate resource on birds – The Birds of North America – says the “lack of information can be attributed, at least in part, to the inaccessible nature of the nest; even if it can be located, hidden in hanging tendrils of epiphytic growth, it is usually high in a tree, and often in moist, swampy habitat. Thus far, because of closed structure of nest, it has proven impossible to directly observe activities that take place between nest construction and fledging of young.”
Their primary song is very easy to identify, suggesting a zipper being zipped up, or a rising buzz.
Parulas are uncommon in the Northwoods because of their adaptation to nesting in northern conifers that host masses of Usnea. Only 42 observations of breeding pairs were confirmed for the Wisconsin Breeding Bird Atlas, and only four of those also included actual observations of a nest.
The Grand Portage
Grand Marais is just south of the Canadian border, and thus close to the famed Grand Portage, which linked the French voyageurs on Lake Superior to the vast interior of Canada north to Great Slave Lake and west to the Athabasca River. The 8.5-mile-long Grant Portage bypassed the wild rapids and waterfalls of the Pigeon River and for a period was the site for the headquarters of the North West Company. In mid-May after the ice break-up, the men posted in western Canada returned with their furs to Grand Portage to rendezvous with another group of voyageurs who had left Montreal at the same time. Two months and thousands of miles of paddling later, they met to exchange the furs for trade goods, to exchange news and supplies, and to partake in some serious “entertainment.”
The Grand Portage trail took the voyageurs a few hours to traverse while typically carrying two 90-pound packs. The post and trail were abandoned in the early 1800s, and the trail obscured by fallen trees and vegetation. In 1958, the Grand Portage band of Ojibwe donated the lands surrounding the Grand Portage, and that same year, it was designated a National Monument.
The trail today is rarely hiked its entire length since one must go out and back, a 17-mile roundtrip which is not particularly scenic given that the purpose of the trail was to find the flattest and easiest path possible for hauling goods and canoes.
We hiked just a short section of it, but I hope we’ll go back another time and hike its length. It’s rare today to be able to hike any trail that is many centuries old, and rarer yet to hike a trail of such historical significance. Native people are known to have lived in Grand Portage area for nearly 2,000 years, so perhaps the trail is as old as that.
Superior Hiking Trails
Mary, Callie, and I hiked some portion of the Superior Hiking Trail every day we were there. I’ve written about this trail system before, but it bears repeating given the exceptional quality and length of the trail. The main trail runs 235 continuous miles from Two Harbors to the Canadian border, with an additional 39 miles of trail through Duluth. More importantly, the rugged and steep trail climbs cliffs, runs along ridges, follows rivers with dramatic whitewater, and bisects an array of forested habitats with abundant wildlife.
Mary and I are leading a hike for Nicolet College there in September and will be staying at the extraordinary Naniboujou Lodge northeast of Grand Marais, a trip I hope we repeat for many years to come.
Sightings
5/10: Bob and Sandy Alfano in Woodruff reported their first northern oriole
5/12: John Werth reported a moose wandering east of Boulder Junction.
5/12: We saw our first-of-year (FOY) yellow warbler near our home in Manitowish.
5/12: Dan Carney saw a FOY chestnut-sided warbler near Hazelhurst.
5/15: We had our FOY least flycatchers at the Van Vliet hemlock stand.
5/15: Dan Carney saw a FOY golden-winged warbler and yellow-throated vireo near Hazelhurst.
5/17: Jane Flannigan reported the FOY indigo bunting in Hazelhurst.
5/18: Wendy Ross and Don Kassien in Boulder Junction saw a sow black bear and four cubs cross Hwy. M. “She had two cross with her and there were two others up a red pine. She made 4 trips back across the road to get the two out of the tree!”
5/18: Dan Carney reported FOY Tennessee and magnolia warblers.
5/22: Eastern gray tree frogs were singing like crazy in Manitowish.
5/24: We saw our first lightning bug of the year below our house.
Hummers Late Arrival
Despite our warm spring weather, ruby-throated hummingbirds arrived unexpectedly late this year. Here are some of the reports I received:
5/11 Pat Schmidt in Hazelhurst
5/14 Sharon and David Lintereur in Lake Tomahawk
5/15 Ron and Pat Drought on Spider Lake in Mercer
5/16 Judith Bloom in Lake Tomahawk
5/17 Diane Shay in Arbor Vitae (the latest in the 10 years she’s been keeping records)
5/17 Jane Flannigan in Hazelhurst
Pine Pollen
On May 24, pine pollen was dusting everything in our yard, an event we usually don’t expect until the second week of June. If you’re seeing a yellow film on water, it’s very likely pine pollen. The male pollen cones are smaller than the female seed cones, and they shrivel and dry up as soon as the pollen has been shed.
The quantity of pollen produced is enormous. Each pollen grain is tiny – about four one-hundred-thousandths of an inch and viewable only through a scanning electron microscope. All are windborne and pollinate the open, very small and newly formed female cones, which will continue to grow into large, hard, green, tightly closed cones by this fall.
Lakeland Discovery Center Bird Fest
Participants in the NLDC Bird Fest held on May 15 tallied 93 species of birds, an excellent number given that many migrating neotropical species had yet to arrive in our area. Last year, we birders had to deal with strong winds and a few snow flurries. This year we were wearing short sleeves later in the morning.
The event attracted 90 or more people, and as always, was well organized and highly enjoyable. Kudos to the NLDC staff and volunteers for showcasing the birdlife of our area.
Drought Update
We are continuing our six-year-long adventure with drought. As of May 18, nearly all of Vilas, Oneida, Forest, and Florence counties were in severe drought conditions as determined by the U.S. Drought Monitor. Water levels on many local seepage lakes are at record low levels (seepage lakes are those without an inlet or outlet source of water, and thus are only fed by precipitation and groundwater).
Celestial Events
We will be blessed with 15 hours and 30 minutes of daylight as of June 1; summer solstice will be here shortly!
Planets viewable at dusk in June: Venus low in the northwest, Mars in the southwest, and Saturn in the southwest. Planets viewable at dawn in June: Mercury very low in the east until mid-month, and Jupiter low in the southeast.
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