A Northwoods Almanac for October 14 – 27, 2011
Peak Robin Migration
At Hawk Ridge in Duluth, the primary focus is always on hawks migrating over the ridge, and the fact that songbirds also fly over often goes unnoticed. Well, on 10/4/11, the hawks were insignificant in number, and all the action was instead with songbirds. The counters tallied 9,690 migrating non-raptors that day, the vast majority, 9,050, of which were American robins. That number was not an anomaly either. The day before, 10/3, 5,035 robins crossed over the Ridge, and the day after, 10/5, another 6,524 flapped by.
Just to show the migration action isn’t all at Hawk Ridge, a few days later on 10/9, DNR biologist Ryan Brady counted 13,836 robins migrating over his house in Washburn between 7:15 and 10:15 a.m. He reported, “The sky was full of migrating robins – masses of birds constantly streaming by, in every direction, at every height, both along the lakeshore and inland, but all headed south-southwest. Most flocks were 100-300 birds thick, and I counted by 10s, 25s, or 50s, clearly missing many as it was impossible to keep up with all the action.”
Those numbers are particularly impressive because not all robin populations are migratory. Robins that nest as in our area and further north nearly always migrate, and the massive seasonal migrations noted here occur across large areas of Canada and the northern U.S. in response to the availability of fruit in the fall.
Surprisingly, however, robin migration remains poorly understood despite how common their commonality. What is known is that robins migrate in flocks primarily during the day, often in large flocks of hundreds or thousands of immature and adult birds. But individual robins do not return to their same wintering territories as many other songbirds do. Nor does the term “routes” seem to apply to robin migrations.
Banding records show that robins wintering in a particular place are usually from widely scattered areas to the north. For instance, individuals recovered in Florida in winter are from as far west as North Dakota. So, robins appear to be “plastic” in their migration, often picking a new wintering strategy as conditions dictate.
Best Hiking
Mary, Callie, and I took as much advantage as we could of the glorious fall weather we were given over the last two weeks. The leaves mostly came down in the recent high winds, but last week the autumn hiking was spectacular. Our four favorite local hikes we took this fall were around the Van Vliet Lake Trail, the Uller Trail west of Hurley, the Tramper’s Trails around Star Lake, and the Anvil Trail east of Eagle River. Give them a try if you’ve never hiked them – I think you’ll come away very happy.
Still in Flower
Big-leaf aster remains in flower in the woods, along with a few other remarkably hardy “roadside weeds” like pearly everlasting and a few daisy fleabanes. The witch hazel we planted in our yard is also in flower, and probably garners the prize as the latest flowering shrub in the Northwoods.
Sunflower Seed Price!
The cost for a fifty-pound bag of sunflower seed has hit nearly $40, apparently due to Ore-Ida, a brand of potato-based frozen foods currently produced and distributed by the H. J. Heinz Company. Ore-Ida accounts for a large amount of the processed potatoes sold – think “Tater Tots” – and they recently switched from using corn oil to sunflower oil. Thus, they purchased most of the sunflower crop, which led to these astronomical prices.
The name was used in the company's long term advertising slogan: “When it says Ore-Ida, it’s All Righta.” Well, it’s not All Righta that the price of seed has gone through the roof. The cost will certainly dampen enthusiasm nationally for feeding birds this winter.
Yellow-rumped Warblers Still in Migration
We’ve had a least a dozen yellow-rumped warblers foraging in our yard for the last 10 days, likely stalled in their migration due to the prevailing south winds. Yellow-rumps are one of the last warblers to migrate in fall, remaining in their northernmost breeding areas into October. On occasion, they’re known to linger north of their winter range into December when both the climate and food supplies are favorable.
Interestingly, yearling males winter north of older males, while yearling females winter south of older females. During the winter, the sex ratio in northern wintering areas shifts even more strongly toward males, while females increase in the southeast U.S.
Sightings – Hummers, Moose, Badgers, Hawk/Flicker Predation, and Bluebirds
Renn Karl in Presque Isle sent me photos of a male ruby-throated hummingbird nectaring in their still flowering Million Bells hanging baskets. Renn noted, “We had 'hummers' late into September, but I haven't seen a male in weeks! I can never recall having 'hummers' into October! He appeared healthy, quite plump, [and] intent on eating.”
Ginny Grueneberg called on 10/3 to say she had just seen a moose in her yard on Hwy. 70 near Mitten Lake Road. She said her dog was barking, so she stepped outside to see what the commotion was, and noticed the hair on the dog’s back was standing up. And then from between the house and her garage, out stepped a moose! The moose walked down the driveway, turned off into the woods, and headed east. Later that same day, there were reports and photos of a young bull moose seen on Lake Shishebogama, and I suspect it was the same moose on a walk-about.
Annette Tellefson in Manitowish Waters noticed some very large holes that were dug at night in her yard next to some chipmunk holes. She confirmed that next day that it was the work of a badger.
Grace Wanta on the Turtle Flambeau Flowage called on 10/5 to report seeing a flock of Eastern bluebirds at her house for the previous three days. Usually the few bluebirds we have up here are long gone by the end of September, and any northern migrants have passed through, but our warm October apparently induced this flock to stick around.
Carol Ritter-Eaton in the Lake Tomahawk/Cassian area sent this sighting: “About three weeks ago, Mike went out our back door into the garage. Just off the paved apron on the ground in front of the garage was a hawk feasting on a flicker it must have just killed. There had been 5-6 flickers in the yard for several days, though now they are gone. The hawk immediately flew down a footpath into the forest, carrying the flicker in its talons.”
Autumn Scents
Carol went on to ask in her e-mail, “What is the wonderful alehouse smell of the woods in the fall? It is usually pretty localized, except this year it is much more diffuse during those grey rainy days last week. I noticed it most in the pine plantations, but also in some hardwoods. Very yeasty and fermentative, so I always assumed it was some type of plant breaking down, but could never pinpoint it.”
Well, I don’t have any fancy scientific articles to point to. I think we’ve all picked up a handful of leaves and stuck our nose in there, breathing as deep as we could that unique odor of autumn. Oak leaves smell different from maples, which are different from ash, which are different from pine needles. It’s just a smorgasboard of smells, all very well described by Carol as an “alehouse.”
Why Do Deciduous Trees Drop Their Leaves?
I’ve always thought that deciduous trees in the Northwoods dropped their leaves because, given the frozen drought they experience in winter, they would die of thirst if they held on to them. Well, biologist Bernd Heinrich in his wonderful book “Summer World” suggests that “a large leaf surface area is needed to intercept solar radiation and to absorb carbon dioxide in the summer; but the same leaf surface is a liability in the winter because snow loading could collapse the tree.” He goes on to describe early autumn snows that wreaked havoc on trees that had still retained their leaves, breaking branches and often snapping the main trunks.
I was a bit surprised to read that there’s still controversy as to just why trees drop their leaves. These common and “elementary” events in nature seem easily explainable until one looks more deeply into them and finds complexity where he expected simplicity.
Celestial Events
Today, 10/14, we’re down to 11 hours of daylight.
The peak Orionid meteor shower takes place on the evening of 10/21. You can expect around 15 meteors per hour all seeming to originate from the constellation Orion. Unfortunately, the rather large waning crescent moon will obscure the shower somewhat, although the moon doesn’t rise until after midnight. But the Orionids usually wait until the wee morning hours to pick up steam, so sometimes you can’t win. Still, these fast-moving meteors occasionally leave persistent trains and bright fireballs, so it just might be worth staying up!
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