A Northwoods Almanac 5/28/10

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.

A Northwoods Almanac 5/14/10

A Northwoods Almanac for May 14 – 27, 2010

Sightings

On 4/18, Jane Flanigan in Hazelhurst thought she had sighted an eastern bluebird, so she promptly put up a bluebird box. No bluebirds showed up, however, and five days later black-capped chickadees moved in! But on 5/1, the bluebirds arrived, evicted the chickadees, and are now nesting.

On 5/1, barren strawberry came into flower in the Manitowish Waters area.

On 5/2, Dan Carney in Hazelhurst spotted first-of the-year palm and Nashville warblers along the Bearskin Trail. 

On 5/2, Pat Schwai on Cochran Lake reported the first black-throated green warbler of the year in our area. 

On 5/3, we found gaywings in flower near Mercer.

On 5/5, we had our first rose-breasted grosbeak appear at our feeders.

On 5/6, Linda Johnson on the Tomahawk River reported the following: “While sitting in the den my husband heard an enormous bird strike against the window. In fact, he thought the window was shattering. Upon looking outside he saw a small hawk (sharp-shinned?) on the deck in a very contorted position. He went out and carefully righted the bird and then noticed a grackle lying on its back with its beak and eyes wide open about 20 feet away. He also righted this creature. Kevin had time to come in the house, dig out his camera and snap a couple shots. Then he let the two of them have some quiet time to either make it or not. About 20 minutes later he checked back and both birds were gone.”

  Linda also noted that she watched a pair of northern flickers, the male of which was doing a display for the other by fanning his tail and hopping toward her. Apparently the female wasn’t impressed and flew away.

On 5/7, Mary and I observed gosling chicks on the Manitowish River. We also had our first northern oriole in our yard.

On 5/9, Sharon Lintereur in Lake Tomahawk reported the first indigo bunting of the year. She noted, “They are right on schedule according to my records.”   

On 5/10, Diane Gaynor reported the first scarlet tanager of the year on her deck in Arbor Vitae.

Vultures Nesting?

On 4/30, Gloria reported the following from a site north of Rhinelander: “I was walking with my friend Jody . . . we scared up some vultures that were in an old fallen down building along the road. Not one or two, but at least 7 vultures came out of the building. We looked in the window expecting to see a dead elephant for that number of birds and could see nothing. Is this normal for this number and type of bird to roost in a building, or should we assume that they were feasting on something we did not see?” 

On 5/9, Gloria followed up her earlier post with this note: “Went and checked out the site today and scared up five vultures from the building, so they must be roosting or nesting in there. Two of the birds were pretty reluctant to fly far from the site.” 

The question I had for Gloria was whether she thought a pair might be nesting in the building (though the fact that there were 5 to 7 birds in the building would seem to suggest a roosting site rather than a nesting site). The reason I asked her about possible nesting is that data from The Atlas of the Breeding Birds of Wisconsin confirmed 33 actual nest sites statewide, half of which were in rock outcroppings. But about a third of the nests were found in artificial structures, of which most were in abandoned houses and farm buildings (three were found in elevated deer-hunting blinds!).

Atlas field observers were unable at that time (through the year 2000) to confirm any vulture nests in Oneida Country, but eight sites were listed as possible. Since turkey vultures tend to be secretive at their nest sites, the lack of confirmed nest sites may not demonstrate that no vultures were nesting here, but may simply indicate how good the vultures are at hiding their nests.

Turkey vultures were considered rare in Wisconsin until the mid-1900s – the first confirmed vulture nest in the entire state wasn’t found until 1947. But their population has been steadily on the rise since then, with mean annual population increases calculated at 15% for Wisconsin.

If Gloria’s site proves to be a nesting site, the female likely laid her average of two eggs in late April or early May. Incubation is by both adults, and lasts 28 to 40 days, with chicks usually appearing around June 1.

Turkey vultures are highly social, however, and roost communally throughout the year, so they may just be hanging out in the evenings in the abandoned house or loafing there during the days. Vultures typically roost in dead trees, on cell towers, and often on roofs. Though I’ve not heard of them roosting or loafing inside abandoned houses, I wouldn’t be in the least surprised – I’d think they’d like a roof over their heads.

Jazz Singers

On 5/4, Mary and I were awakened at dawn by a bird singing a wildly creative song below our open window. It took us both a moment to clear our heads, and then we looked at one another and said simultaneously, “Brown thrasher!” The thrasher was continuously riffing notes like a jazz musician at a late night club in Chicago. The songs came fast and furious in no discernible order or melody, the only distinguishing pattern being the repetition of each note in couplets – hi there, hi there . . . how are you, how are you . . . good day, good day . . . listen up, listen up – each couplet occurring about a second apart. We never heard any individual couplet repeated later in the overall sequence, though the thrasher voices so many songs that we’d have to record them and play them back in a lab to discover any duplicates. The thrasher sang his heart out for about 10 minutes, then departed, and we haven’t heard another since.

I hope one returns soon. The brown thrasher holds the world record among birds for most songs sung by a species, with a repertoire of somewhere between 2400 and 3000 distinct songs – researchers can only estimate the number. No other bird on Earth is so skilled and so versatile a songster. 

Donald Kroodsma, author of The Singing Life of Birds, recorded in mid-May a brown thrasher as it sang thousands of songs for two hours from its perch in an oak tree. He later counted the songs and found that it sang 4,654 couplets. He then had the arduous task of printing out sonograms of each song and comparing them to see what songs were unique and what songs were repeated. Kroodsma eventually estimated that the thrasher sang about 1800 different song couplets in those two hours, but that was just one bird in one place for two hours. How many more songs did that thrasher know, or could improvise, but didn’t have time to sing? If thrashers improvise their songs, it could be true that they have an infinite array of songs. 

Not long after doing this recording, Kroodsma heard two male thrashers singing in another area, the second thrasher echoing precisely every song the other thrasher was singing. He later learned of another researcher who played thrasher songs over a loudspeaker to a resident male, and that thrasher matched the tape song for song.

Kroodsma, a world-renowned expert on bird song, knows of no other songbird in the world with the ability to repeat another bird’s songs instantly. Most birds simply repeat the same song over and over, like a chipping sparrow. It’s the same song today, tomorrow and next week. Some birds have a small variety of songs they repeat, which usually occurs in a predictable pattern. But no bird comes close to the repertoire of the brown thrasher.

A last question one must ask is why? Why sing so many different songs? No answer, of course, will ever be known, but since songs are sung with the primary intent of attracting a female, perhaps the brown thrasher female has the most discriminating ear of any species on Earth. Kroodsma also allows that “I have to consider the idea that this master of the largest song repertoire known among birds is somehow enjoying himself.”  

Migration Is On!

On 5/5, a birder in the Appleton area observed a “fall out” of 20 species of warblers in one hour while sitting still in one spot. Twenty-four species of shorebirds were reported on 5/6 near Madison and the Horicon marsh area. Hawks were migrating hot and heavy two weekends ago (May 1 and 2) on strong southerly winds. The hawk counter at Brockway Mountain in Copper Harbor, MI, reported over 1500 hawks coming through in a three-hours span on 5/1. 

So, this is the time to keep an eye skyward for waves of warblers and hawks and whatever else a southerly breeze might bring.

Celestial Events

Planets visible at dusk in May: Venus low in the northwest, Mars high in the southwest, and Saturn high in the south. At dawn, look for Mercury very low in the northeast, Jupiter low in the southeast, and Saturn setting in the west.

On 5/16, look at dusk for Venus just below the two-day-old moon. May 17^th blesses us with 15 hours of daylight. On 5/20, look for Mars about 5 degrees south of the first quarter moon. Full moon – the “Planting Moon” – occurs on 5/27. This is the year’s southernmost/lowest full moon, climbing only 18° above the southern horizon.

Drought Update

Our total precipitation so far for 2010, as measured at the Minocqua Dam at the end of April, was 2.43 inches, a deficit of 3.87 inches for the year (we normally average 6.3 inches) and down 33.74 inches since 1/1/03.

Transformation

If I had to pick the two most exciting weeks of the year to be alive, I’d pick these last two weeks of May. The plant world achieves the greatest of transformations, transitioning from a 5-month-long white-out to a full-tilt, eye-popping greenery that includes every shade of green one could imagine, emanating from literally billions if not trillions of leaves. 

The neotropical songbirds arrive across the North Country by the tens of thousands, having winged their way across thousands of miles of land and water to arrive in our backyards and forests and lakes. They bring with them a riot of songs that transform every early morning into a free ticket to one of the greatest concerts on Earth. Just wake up at dawn and open the window. Better yet, take a walk as the world awakes, and soak in all the expressions of life and ardor and, if you will, joy. There won’t be another time this year when life is at this height of expression. You’ve spent, as they have, a long winter under wraps. It’s time to enjoy.