A Northwoods Almanac for Nov. 15 - 28, 2019

A Northwoods Almanac for Nov. 15 - 28, 2019  

Goose Migration

            We’ve heard and seen many flights of geese going overhead in the last few weeks, but some geese may still hang around until the final formation of ice and the deposition of snow forces them south. It’s not cold that moves them – they’re very winter-hardy birds. It’s the lack of food due to snow and ice. If we would have winters with less than 5 inches or so of snow on the ground, many would likely remain. 

            Bill Volkert, retired wildlife biologist at Horicon Marsh, has written about winters between 1976 and 2010 “varying between no geese in years when we had 12 to
18 inches of snow and one particular year when we still had 124,000 geese on the
marsh.”  He notes, “The first migrant geese usually arrive at Horicon between September 15 and
20 . . .  We usually hit peak numbers around the end of October to early November . . . The migrants will usually begin to depart around early to mid-December no matter what the weather, while others will remain as long as they can – until we have a good snow cover.”  

             Interestingly, he says the geese we see just overhead are seldom migrating. “True migration is not regularly observed . . . When geese are making daily feeding flights, they usually fly between 100 and 500 feet high. The farther they are flying from one site to another, the higher they will fly. However, when geese are truly migrating, they will fly 2,000 to 5,000 feet high, depending on favorable winds, and have been recorded flying as much as 10,000 feet up.” 

            Where do the geese winter? Volker writes, “The geese that stage at Horicon Marsh nest in the lowlands around James and Hudson Bay, and winter in southern Illinois and western Kentucky and Tennessee around the confluence of the Ohio and Mississippi Rivers. [But] In years of mild winter weather, some geese will stay at Horicon or simply move to southern Wisconsin or northern Illinois.”

Tamaracks

            The tamaracks should have all lost their needles by mid-November, the only conifer in the Northwoods, as we all know, that is deciduous. The question that always comes up is why? Why do tamaracks lose all of their needles when our other conifers only drop some every year? 

            Tamaracks appear to be trying to take from the best of both worlds, conifer and deciduous. Deciduous trees like maples and birches construct thin leaves with high surface areas (thus the name “broad-leafs”) that are masterful at photosynthesizing at high rates. The cost of this strategy is they lose water easily, an impossible problem to overcome in the winter when the air is dry and groundwater is tied up in ice. Plus, the thin leaves are attractive to insects, shred easily, and struggle to shed ice or snow, which leads to broken limbs and downed trees. Thus, they drop their leaves before winter and replace them in the spring.  

            Evergreen conifers chose a more conservative strategy by making their leaves into short, skinny needles and coating them with waxes that reduce water loss and aren’t attractive to insects. These tough needles can also withstand winter’s abuse, shed ice and snow, and still photosynthesize when we have warm-ups in the winter. All the needles still need to be replaced eventually, and every conifer drops some percentage of its needles each year, but needles can last for years. The downside is that the needles photosynthesize at lower rates than the leaves of broad-leaf trees, thus they tend to grow slower.

            Both strategies work, but there are trade-offs that each camp accepts. 

            Tamaracks came along and thought maybe there was a middle ground – a liberal conservatism if you will. Tamaracks grow a spray of soft needles about an inch long in sparse clumps along their branches, which means that a high percentage of the needles receive full sun. Forest ecologist E.C. Pielou in her book The World of Northern Evergreenswrites, “larch [another name for tamarack] needles are small and widely spaced, so that on a given tree, they shade one another to a lesser degree than do those on both evergreen trees and broadleafs.” More sun beaming onto less waxy needles means more photosynthesis and the creation of more nutrients in summer than their conifer cousins. So, in effect they’ve adopted the broad-leaf trees strategy in that regard. 

            But tamaracks live all the way up to the tree line in the Arctic, so they need to deal with the snow damage and water loss that would occur on their less hardy needles. The solution – drop their needles. But before they’re shed, tamaracks are apparently able to reabsorb a high proportion of nitrogen from their needles – perhaps 20 percent more than other species of trees –  a big savings toward next year’s growth.

            Whatever the science behind their wintering strategy, we’re always the beneficiaries of their last golden glow before the white of winter.

Snapping Turtle Hibernation

Snapping turtles hibernate in shallow water, burying themselves usually in groups in the mud in places which do not freeze to the bottom. During that time their body temperature is reduced to about 34°F, or just above freezing – any lower temperature and the turtles can freeze to death or be killed by the forming ice. 

During hibernation, they rarely move, and in their far northern range, they don’t breathe for more than six months. They get oxygen instead by pushing their head out of the mud and allowing gas exchange to take place through the membranes of their mouth and throat, a process known as extrapulmonary respiration.

Sightings

            11/6: Bob Von Holdt sent me a photo of a northern shrike that attacked a house finch at his bird feeder in Stevens Point. 

 11/3: John Randolph reported seeing a gray catbird “in an alder thicket on the edge of our lake [Minocqua area], and then I heard it call the next day. Today [11/8], driving back from an errand in town, I saw it again, flying into the same thicket . . . I was surprised to see it so late in the season, and more so to see it again today.” 

            Gray catbirds are supposed to depart their northern breeding grounds in late August and into early September, but apparently this one didn’t get the memo. If it does finally get and then read the memo, its wintering range stretches from the southern New England coast south to Panama, with concentrations on the U.S. Gulf coast and the Yucatan Peninsula. I hope its GPS is better than its calendar.

            Caroline Sedlak sent me numerous excellent photos of otters on her lake, while

Kent Dahlgren in Presque Isle set a trail camera up near the shore of his lake and also got a fine picture of an otter. Trail cams are making a big difference for folks in learning what’s happening on their property. I’d like to recommend to readers of this column the best trail cameras to buy – please send me your recommendations! Mary and I need to buy one as well.

         

photo by Caroline Sedlak   

            We’re seeing numerous flocks of snow buntings along roadsides. As ground feeders, they’re passing through on their way to places with little or no snow cover. They’re exceptionally easy to identify – no other songbird at this time of year shows anywhere near as much white on its body as snow buntings. I’ve purposely attached a rather poor photo of a flock of snow buntings to show you the view most of us get of snow buntings while driving along at 50+ mph on a county road. 

Early Ice Locally! But Warmer Lake Superior

            Two weeks of well-below average temperatures in late October and early November have led to an early ice-up on our area lakes. Statehouse Lake in Manitowish Waters was ice-covered as of 11/7. 

Woody Hagge’s 43 years of data for Foster Lake in Hazelhurst shows an average ice-up date of Nov. 27; however, size and depth matter in ice-formation. Foster is a relatively similar lake in size and depth to Statehouse Lake (Foster is 39 acres with a maximum depth of 38 feet and Statehouse is 23 acres with a maximum depth of 18 feet), but given Foster’s larger size and depth, it freezes a bit later than Statehouse. 

On the other hand, demonstrating the crucial difference once again between transitory weather and long-term climate data, climate change is causing Lake Superior to be among the fastest warming lakes in the world. Even with Superior's immense size, it's not immune to environmental changes. The lake's average surface temperature in the summer months has risen 2° C (3.6° F) over the past 30 years. While that may sound small, a few degrees can have a dramatic effect. The University of Minnesota Duluth is studying the presence of blue-green algae blooms reported on Lake Superior's south shore, particularly two large bloom events — one in 2012 and one in 2018, the latter bloom stretching all the way from the Duluth east to the Apostle Islands, about 60 miles. The question is whether the correlation between the warming and the algae is a coincidence or whether the warming water is directly contributing to these new incidents of blue-green algae. 

Early ice means the possibility of lake ice skating for Mary and me, and great ice fishing for those anglers itching to get on the ice. Get out and enjoy!

Celestial Events

            For planet-watching in mid-to-late November, look after dusk for Venus, Jupiter, and Saturn all very low in the southwest, with Venus lurking below Jupiter most of the month. By month’s end, Venus will have moved above Jupiter. To know which is Jupiter, you should be able to see at least one of its moons with binoculars. Saturn isn’t as bright as Jupiter, but still ranks with our sky’s brightest stars. Hold your fist at arm’s length. Saturn is roughly two fist-widths to the east of (or above) Jupiter. You can see Saturn’s rings with a spotting scope or a telescope.

Before dawn, look for Mars very low in the southeast. 

            The peak Leonid meteor shower occurs before dawn on 11/18.  The Leonids average 15 meteors per hour. 

            On 11/24, look before dawn for Mars 4° below the waning silver moon. Look after dusk for Venus and Jupiter to be within one degree of one another.

The new moon occurs on 11/26.

Thought for Thanksgiving

            “How can we reciprocate the gifts of the Earth? In gratitude, in ceremony, through acts of practical reverence and land stewardship, in fierce defense of the beings and places we love, in art, in science, in song, in gardens, in children, in ballots, in stories of renewal, in creative resistance, in how we spend our money and our precious lives . . . in healing.” Robin Wall Kimmerer