December 29 Winter's Dew

With students on the trail this morning at Aldo Leopold Nature Center, we discovered a whole bunch of hoar frost along the ground. Like summertime dew, hoar frost forms because air can no longer hold up the water in it. As the temperature drops overnight, colder air molecules are more spread out, and if they spread out enough, we reach the Dew Point. Now the water falls onto plants and the ground. In winter, the water falls as ice crystals which latch on to blades of grass, leaves, or your bedroom window.

December 28 Lady Downy in a Nest?

Back out on the Picnic Point this Sunday afternoon, I watched this female downy woodpecker (Picoides pubescent) chase another out of this tree cavity. It then went all the way in, drilled for a moment, and retreated to fling wood chips out of the hole. Woodpeckers usually begin courtship in late winter, but in recent days I have heard more than one bird species make mating calls. My guess is that the warm weather has our resident winter birds feeling giddy. While they likely won't mate until closer to the average time, birds especially will get a head start if given an opportunity, including claiming a great nest site. This downy woodpecker may be doing just that.

December 27 Only Mallards at Canal Park

On our way back to Madison, we stopped at Canal Park in downtown Duluth to check for waterfowl one more time. Aside from resident gulls, only a small flotilla of mallard ducks (Anas platyrhynchos) swam back and forth in the canal. Migrant fowl have long since departed Lake Superior, compared to the variety of swans, ducks, geese, and , some of which are lingering on the still open waters in the capital city.

December 26 The Clue in the View from Rock Knob

On our last day in Duluth, we walked the trails at Hartley Park hoping to see interesting winter birds. With only chickadees chattering here and there, I turned my attention to the park's vegetation. This view from Rock Knob gives a sense of human induced plant communities. Before it became a park, this piece of forest was Allandale Farm, purchased by G.G. Hartley in 1896. By 1918, much of the forest had been cleared for pasture, and remained a grazing area until the fields were abandoned in 1931. Hartley became a city park in 1941, and several red pine plantations, like the green bands seen in the photo, were planted in the 1960s. Where pines were not planted, sun-loving species like white birch (foreground, red tops) and quaking aspen (upper right), grew quickly on the abandoned fields. These dense stands of single tree species are a clue to the human history of this exceptional city park.

December 25 How Many Trees?

Out in the yard today, I noticed these sapling spruces growing under a bench in the driveway.  This made me wonder, how many Christmas trees are growing in the United States? I read that there are over 300 million Christmas trees growing on 15,000 farms scattered throughout all 50 states. 25-30 million of these are sold each winter, which means that people prefer artificial to real Christmas trees by a 2 to 1 ratio. Of course, then there are some families like mine, who have an artificial tree but have recently been buying real trees. In any case, 350,000 acres of land are growing fir, spruce, and pine trees that produce oxygen and create habitat for an average of seven years before they go into our living rooms.

December 24 Christmas Eve Birding

The warming trend continues here in the north, as we lost most of the remaining snow cover overnight. This is good news for Duluth's wintering songbird population, including red-breasted nuthatches (Sitta canadensis). These energetic creatures commonly rely on conifer seeds in the winter, many times walking down the trunk of a tree to locate cached seeds in the bark. This one enjoys bites of suet (animal fat) in a backyard feeder, and flies off to swallow its morsels in secret. Weighing only 10 grams, this bird must be thrilled to have 32 degrees on Christmas Eve.

December 23 Duluth Backyard Squirrel Watching

I didn't travel far today, and so watched gray squirrels (Sciurus carolinensis) stealing compost from the back yard. With a high temp today of 38 degrees Fahrenheit, the precipitation fell as rain instead of snow. With hardly any snow cover (more grass than snow in Duluth), I wondered if 38 and rain was more hospitable to these small mammals than -10 and snow. I've read that with a foot of snow insulation, ground temperatures remain above freezing for squirrels and other tunneling mammals. However, with the compost pile and fallen birdseed readily accessible, I have a hunch that Duluth squirrels prefer 38 degrees and a wet coat.

December 22 Lake Superior Break Up

In Duluth for the holiday week, I went walking out on Minnesota Point, a peninsula in Lake Superior that stretches almost to Wisconsin. A year ago this time, Lake Superior was on the verge of a major freeze up, building up to the most ice it saw since 1993-1994. It is often said that climate is what we expect and weather is what we get. Average temperature and snowfall are the results of warm winters and cold winters and dry winters and snowy winters all added together. But to have a winter, or a month, or even a week, that reflects the averages is uncommon. Lake Superior may remain unfrozen this winter, but if so, that will only average out last winter's deep freeze.

December 21 Winter Solstice

Again on the Turtle Flambeau Flowage, I walked in search of shadows on this, the shortest day of the year. With the sky in complete overcast, I didn't find any. With not much of a prospect to photograph sunset or the night sky, I chose to look at these sedges, fallen over into the frozen flowage. Tonight will last 15 hours in Madison, after just 9 hours of daylight. But don't worry, the sun's rays will get stronger now as the northern hemisphere tilts toward it a little more each day. By February 1, we'll have 9 hours, 57 minutes of daylight.

December 20 Red Squirrel Midden

I discovered this midden (a mammal's food cache or food debris) while on a walk on the Turtle Flambeau Flowage in Iron County. Tracks on either side revealed that a red squirrel ate breakfast on this downed red pine. Weighing in at less than a pound, it is remarkable that these creatures stay active during Wisconsin winters. Red squirrels are solitary for much of the year, but now may stay warm by huddling in tree cavities with family and friends.    

December 19 Hooded Merganser Double Date

Heading west on Broadway I noticed these pairs of Hooded Mergansers (Lophodytes cucullatus) circling in the Yahara River. The black-and-white-crested males appeared to be flirting even though breeding season doesn't start until March. They swam back and forth around the cinnamon-topped females while bobbing their heads back and then up. Are these males confused about the season after our December thaw? Hooded mergansers are year round residents in Madison, but will seek out larger lakes and rivers as needed in winter.  

December 18 One Milkweed Seed Left

This common milkweed (Asclepias syriaca) pod shows one remaining seed after a fall spent bursting open to allow seed dispersal. Feather light threads connect the clump of seeds in each pod, sending them skyward once the pod has cracked open. The pod and stalk will continue decaying through the winter and return nutrients to the soil in the spring prairie fire at Aldo Leopold Nature Center.

December 17 Cedar Waxwing Dinner Buffet

In Paunack Park along the Yahara River as it exits Lake Monona, I stopped my bike to watch a flock of at least a dozen cedar waxwings eating buckthorn berries. Cedar waxwings (bombycilla cedrorum) are year round residents in Madison and almost always seen in flocks unless they are nesting. They love fruit and will eat it almost exclusively from now until spring. The spread of buckthorn and honeysuckle is helping waxwing populations and they, in turn, are helping those plants by eating their fruits and spreading the seeds.

December 16 Aldo Leopold Nature Center

This is the first day of my photo phenology project. Here is the prairie and oaks after a weekend of fog and rain. No snow cover means severe cold, especially at night, for mammals that rely on snow's insulating blanket to conserve energy.