A Northwoods Almanac for 9/30 – 10/13/2022 by John Bates
Hawks!
I’ve been watching the Hawk Ridge website all September wondering when the big push of broad-wing hawks would finally occur. For this time of year, comparatively few hawks had been soaring over the ridge due to warm southerly breezes – the birds need a westerly or northerly wind to sail south on.
That all changed on 9/20 when the winds turned to the west and then to the north, and 4,440 broad-wings cruised by. The next day, 9/21, 9,108 sailed over. And then came the big flight on 9/22 when 12,020 were observed, and over 5,000 were counted between 9 and 10 a.m. alone!
Broad-wings that migrate through our area typically compress their migration into a two-week peak period between September 10 to 25. Everything comes down to wind direction and the availability of thermals, because broad-wings spend most of their flight-time just gliding. They capture a warm thermal coming off a rockface or open ground, spiral up in that column of air often to a couple thousand feet (maximum altitude of most migrants is estimated at less than 2,500 feet), set their wings, and glide. For every foot they drop in altitude, they glide out 11 feet. So, if they drop 1,000 feet, they’ll have gained 11,000 feet of southward migration – over two miles!
Cornell’s excellent website, All About Birds (allaboutbirds.org), says this is “one of the greatest spectacles of migration. . . . A swirling flock of broad-winged hawks on their way to South America, also known as ‘kettles,’ can contain thousands of circling birds that evoke a vast cauldron being stirred with an invisible spoon.”
That’s an accurate image, because if you are lucky enough to see a large kettle of hawks swirling by, it’s effortless – they just circle all around one another like deep water slowly going down into a well.
They don’t fly all that far in a given day, with daily distances on average varying from 60 miles in six hours of unfavorable conditions to 300 miles in six hours of ridge flight with a favorable wind.
Researchers estimate they spend 40 days in migration, seemingly in no hurry to reach their wintering grounds in Central or South America.
The numbers of broad-wings seen at Hawk Ridge from 9/20-22 follows a typical pattern of increasing numbers during a cold front, as most migrants are sighted on the second or third day following the front, when winds ebb and thermals increase.
They concentrate their migration in mid-September for a variety of reasons. During September, the sun is still high enough in the sky to create updrafts and thermals necessary for their migration. If they wait any longer, these thermals won’t be as strong or predictable.
Fall migration also coincides with dragonfly and damselfly migration, which enhances opportunistic feeding. While they’re a generalized predator, taking a wide variety of food items like amphibians, insects, mammals, and juvenile birds, they have a propensity for amphibians (mainly frogs and toads), which may also explain their migration schedule since amphibians go into hibernation early in the fall.
Generally, broad-winged hawks store little fat for the trip, so conserving energy is critical, as is being able to feed along the way.
As they head south, their route narrows in parts of Central America, concentrating their numbers. People describe these pinch points, such as Veracruz, Mexico, and Panama ,as a “river of raptors” – peak one-day flights of over a half million have been recorded in central Veracruz.
Feather ID
Ever pick up a feather and wonder what it was? I’ve just learned about “The Feather Atlas,” an excellent resource for figuring out feathers: https://www.fws.gov/lab/featheratlas/idtool.php?fbclid=IwAR2cEVCoH5ibCXFkAJq2zGGfF20tTkrmtytG2vdfLiijZA2eQAQClRkHEoE
Door Bluff Headlands County Park
A few weeks ago, Mary and I helped a friend return to Washington Island in Door County, and on our return home we stopped to hike at Door Bluff Headlands County Park, a unique park for its ancient cliff-face white cedars which are likely many centuries old. The park is part of the larger Niagara Escarpment rock formation which rises 200 feet above the Bay's shore. The cliffs are punctuated with ledges and fractures that support a vertical, talus slope forest of white cedar with Canada yew, mountain maple, red pine, basswood, and red elderberry. One cedar in nearby Ellison Bay, only one inch in diameter, was determined to be 250 years old. A little south in Peninsula State park, a 507-year-old white cedar was discovered on Sven’s Bluff on the eastern edge of the SNA in 2005, and another white cedar at Fish Creek south of the park proved to be 616 years old. It’s very likely that older cedars occur on the bluffs, but very few have been aged.
Also of note for the Door Bluff Headlands is its history. Edwin and Grace Walker, Ino Walker and William and Anne Duncan sold 123 acres to the county for $1 in 1944. In 1977, William and Lyn Swift and William and Miriam Over also sold 33 acres of adjacent land to the county for $1 with the premise that the “land be forever used as a park.” Work to develop the park – building restrooms, trails, a well, and a picnic area with grills was halted. In 1970, only a scenic road was created as it was decided to keep the park in its natural state as a sanctuary.
So, the trails are unmarked, though they're well-maintained, and no trail maps are posted.
One other note of historical importance, rock art was found on the cliffs at the Door Bluff Headlands – red painted canoes and numerous other figures that date to 1000-1499CE.
It's a marvelous site, well worth anyone's time.
Sightings: Moose, White Turkey, First Frost
Two sightings of a young bull moose occurred recently: one on Payment Lake in Mercer on 9/19 and another on Sandy Beach Lake in Powell (southern Iron County) on 9/20. Typically, these observations are considered to be a young male out on a long walk-about looking for, well, who knows – love is the most likely. Rutting or mating season occurs from mid-September to mid-October, so that’s the easiest speculation.
A friend near Harshaw sent me a note wondering about how common it is to see a white turkey – he’d seen one in early September among a flock of normally colored reddish-brown turkeys. Well, the literature says turkeys come in four additional colors – smoke, red, black, and white – all caused by genetic mutations. Smoke is the most common color morph, and biologists estimate 1 in every 100 wild turkeys come in this muted coloration. A smoke-morph bird is a light gray with graphite and black details along the body, wings, and tail, but still with a bit of blue and pink coloration on its head and neck.
A red-color morph is very rare and harder to identify (look for rust-red tail feathers), while the white-colored versions are caused by albinism and the black ones by melanism. Albino turkeys are estimated to be 1 in 100,000.
Our first frost fin Manitowish finally occurred on 9/23. We’ve lived here full-time since 1984, and in our first 20 or so years, we always had a frost around 8/20. Frosts now are at least a month later.
Charles Wright School
Last week, the North Lakeland Discovery Center hosted 27 9th graders from the Charles Wright School in Tacoma, Washington, for six days of outdoor education. I had the opportunity to hike with them at the Van Vliet Hemlocks State Natural Area, and I was most taken by the response of one of the students who had just arrived a month ago in the U.S. from China. I had asked about the “soulfulness” of walking in this old-growth forest, and his response was deeply felt. He said he lives in a big city where he has only ever heard a constant sound of traffic and people – he had never heard silence. And he was really moved by it. He said he had never felt peace before.
Some folks question the value of maintaining old-growth – his response is one reason.
Celestial Events
Looking for planets in October? After dusk, look for Jupiter rising in the east and Saturn in the east-southeast. Before dawn, look for Mars in the south. On 10/5, look in the evening for Saturn about 4° above the waxing gibbous moon. On 10/8, look for Jupiter about 2° above the nearly full moon.
The full moon – the “Hunter’s” or “Falling Leaves” moon – occurs on 10/9.
October 4th marks the launch by the Soviet Union of Sputnik 1, the first artificial satellite to orbit the Earth. It sent a radio signal back to Earth for three weeks before its three silver-zinc batteries ran out. It continued in orbit for two months until atmospheric drag caused it to fall back into the atmosphere and burn-up on the 4th of January 1958, triggering the “Space Race” between the U.S. and the USSR.
As of 1/22, there are now 4,852 satellites in orbit, with the U.S. owning the most – 2,944. China ranks second with only 499.
And, if you haven’t noticed, we’re losing sunlight rapidly. By 10/14, we’ll be down to 11 hours of sunlight.
Thought for the Week
In reference to ancient white cedars growing out of the Niagara Escarpment on the Bruce Peninsula in Ontario: “There is nothing like it in Canada,” said Peter Kelly, a member of University of Guelph’s Cliff Ecology Research Group. “These cedar trees have been living on these cliffs for over 1,000 years, including two trees that sprouted from seed before the year 700 AD . . . The oldest of the living trees began life shortly after the death of Mohammed, the founder of Islam, and before Genghis Khan and the Viking colonization of North America.”
Please share your outdoor sightings and thoughts: e-mail me at manitowish@centurytel.net, call 715-476-2828, snail-mail at 4245N State Highway 47, Mercer, WI, or see my blog at www.manitowishriver.blogspot.com.
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