Sunday, March 24, 2013

NWA 3/8/13


A Northwoods Almanac for March 8 – 21, 2013 by John Bates

Sightings – Carolina wren, Townsend’s solitaire, red crossbills, barred owl, ermine
Two rare bird sightings of southern species stand out over the last month. First, Dan and Donna Krejci in Rhinelander had a Carolina wren visiting their feeders since December, though they haven’t seen it for 3 weeks now. Carolina wrens typically winter only as far north as Illinois.
Second, Bob Orgeman in Rhinelander sent me photos on 2/18 of a Townsend’s solitaire perched on a tree overhanging the Wisconsin River. Townsend’s solitaires belong out west where they are closely associated with high mountain conifers, even nesting occasionally above tree line.
Red crossbills continue to show up at people’s feeders. Uwe Wiechering on Sparkling Lake sent me photos of red crossbills at his feeders, as did Cindy Olsofka in Harshaw, while Gordy Seifert  reported seeing them at his feeders in Springstead. Red Crossbills inhabit boreal forests from Alaska to Newfoundland, and mountainous conifer forests south to the Appalachians, Arizona, New Mexico, northern Mexico, and the Sierra Nevada of California. These birds are true wanderers, and may breed wherever they find a prolific source of conifer cones. Hopefully a few of those spending the winter around here will stay and breed!
Uwe Wiechering also sent me a photo of a barred owl perched near his bird feeders, very likely eating the mice under the feeders.
            David Schmoller in Minocqua sent me a photo of a red-bellied woodpecker searching for insects on a dying pine. Dan Carney in Hazelhurst also has a red-bellied woodpecker at his feeders, as well as a red-headed woodpecker and a hoary redpoll.
Finally, Judith Bloom sent me some wonderful photos of an ermine eating from their suet feeder, likely to the chagrin of the local woodpeckers.

Spring is Coming – Believe It!
Sandhill cranes, robins, red-winged blackbirds, and an array of waterfowl are being reported in southern Wisconsin. They’re all poised to come further north when our weather moderates a bit. We usually see our first robins and red-winged blackbirds right around spring equinox on March 21, so keep your eyes skyward.
Great horned owls are also now on their nests incubating eggs, and eagles are busy doing housework around their nests in preparation for laying their eggs, an event usually occurring near the end of March.

Celestial Events
Today, March 8, we receive 11 hours and 32 minutes of daylight, riding the wave toward March 17 when we hit 12 hours and 1 minute of daylight, the first time our day is longer than our night since September 24. The actual vernal equinox occurs on 3/20 when the sun crosses the equator into the northern hemisphere.
The comet PANSTARRS loops around the sun from 3/10 to /15, and should be visible low in the northwest after sunset. Look for the comet in the vicinity of the waxing crescent moon.
On 3/17, look for Jupiter 1.5° north of the waxing crescent moon.

More Cold Data
This morning (3/3), we hit -17°F, a reading which isn’t particularly welcome in March! However, the sun was shining, and by 10 a.m., the temperature had climbed 35 degrees on its way to a high of 30°. Indeed, the rest of the week is forecast to be in the 30s, leading to what will likely be region-wide cheering.
This time of year nearly everyone in the Northwoods suffers from cabin fever and spends inordinate amounts of time dreaming of spring, so writing now about the positive values of extreme cold is the height of foolishness. But apparently I can’t help myself, and it’s all David Schmoller’s fault. 
David lives in Minocqua and recently sent me the entire weather record kept at the Minocqua Dam from 1903 to 2011. He then summarized the coldest temperature data by decade, and noted: “What is happening is this: the past couple decades have seen a drop-off in low-end temperatures, particularly the -30°F and below. They were fairly evenly spread up until the 1990’s. The deepest bottom dropped off in the 1950’s, which is when a lot of data sets start showing signs of warming.” Here’s the chart he sent me:

DECADE OF COLD TEMPERATURE
Days at/or below
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
-40
4
4
3
4
0
1
0
0
0
3
0
-35
4
2
2
7
2
4
10
2
5
1
0
-30
7
13
18
20
9
8
14
17
13
4
0
-25
18
30
35
25
17
19
18
32
28
13
24
TOTAL
33
49
58
56
28
32
42
51
46
21
24

Several things pop out. First and foremost, from 2000 to 2011, the temperatures in Minocqua never hit -30°F or below.
Second, since 1940 we’ve only hit -40° in two of the last six decades. And in the 1990s, that only occurred in an anomalous three-day span in 1996.
Third, the total number of days at or below -25° is at its lowest, by far, in the last two decades.
Most folks greet this sort of data with a delighted “Thank God,” or “That’s great!” because those extreme cold temperatures make life really hard. Cars don’t start, heating bills go through the roof, things start to break, and we immediately freeze just stepping outside to go to work.
I totally get it, and I don’t enjoy it either! But it’s extreme cold, above and beyond all other things, that makes the North the North.
When I say “the North,” I’m thinking about the plants and animals that have adapted to this cold regimen over the last 10,000 years. Back in the 1940s and 50s, UW botanist John Curtis and his students fanned out across the state surveying over 1,000 plant community sites, culminating in his landmark book, The Vegetation of Wisconsin. The book described a “tension zone” in Wisconsin that marked a crossover between the Northern Mixed Forest—closely related to the forests of northeastern Minnesota, northern Michigan, southern Ontario, and New England—and the Southern Broadleaf Forest, which is more like forests you’d see in Ohio and Indiana. The zone stretches across the state in a loose S-shape from Burnett County in the north to Racine County in the south, with species from both floristic provinces intermingling in this narrow zone. 
David Mladenoff, a professor in conservation in the Department of Forestry and Wildlife Ecology at the UW (and a Hurley native), writes: “The tension zone is marked by a climatic gradient, with cooler, moister conditions to the north and relatively warmer, drier conditions to the south . . . You’ll know you’re in the tension zone when you’re heading north and oaks that are dominant in southern Wisconsin, such as bur, black and white, meet up abruptly with red and white pine as well as paper birch and tamarack swamps that are more characteristic of the north . . . You’ll start seeing some birds that are absent or relatively uncommon in the south: common loon, ruffed grouse, osprey, common raven, white-throated sparrow and purple finch. You’ll also encounter northern mammals: snowshoe hare, porcupine, red squirrel, black bear and timber wolf.”
The vegetative differences between the Northwoods and southern Wisconsin are enormous. Curtis’ book includes a map of the number of species reaching their range limits in each county, and you’ll note that 50 plant species reach their range limits in Marathon County, while only one species reaches its range limit in either Iron or Vilas counties.
I bring this up because as our temperatures have continued to annually warm, the tension zone has been moving north. David Schmoller’s data is simple, straightforward, and undeniable – we’ve lost our extremes in cold winter temperatures. Every plant and animal species has a range of temperature tolerance, and when northern temperatures stop falling to those extreme lows, temperature barriers no longer apply, and southern species can live further north.
It’s already happening. Numerous species historically restricted to southern and central Wisconsin have already moved north or are now proliferating where they were once uncommon – cardinals, wild turkeys, and cottontail rabbits come to mind. Less clear is whether our normal northern Wisconsin species are moving further north, but they will. For long-lived species like trees, the movement will be hard to notice, but it will be inevitable.
In March, it’s hard to imagine that too much warmth could be “bad” for anything, much less for plants and for animals. But indeed it is, and at stake is what we now define geographically as our home – the Northwoods. Hard as it may be to accept, and worse, to desire, we need extreme cold.

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