A Northwoods Almanac for 1/4 – 1/17/19
Sightings: Varied Thrush, Red-winged Blackbird, Minocqua Christmas Bird Count
Gayle Derwinski and Dave Osborn in Boulder Junction have a rare varied thrush visiting their bird feeders. Varied thrushes breed from Alaska to California in forests "where spruce trees and alders and crowding ferns contend for a footing, and where a dank mist drenches the whole with a fructifying moisture," so wrote W. L. Dawson in 1923 in The Birds of California. I’m not sure what “fructifying moisture” is, but when Mary and I did an artist-in-residence in the Andrews Forest in Oregon, perhaps the most common bird we saw there was the varied thrush, and Andrews Forest gets 84 inches of rain annually and as much as 14 feet of snow in winter. It’s a very wet place – perhaps even fructifying!
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| photo by Gayle Derwinski |
They breed most commonly in mature and old-growth forests, and that’s where we’ve seen them – from coastal redwoods to western hemlocks. Most varied thrushes winter along the Pacific Coast from Alaska to southern California, but during irruption years, which occur every 2 to 5 years, they may be seen across the United States and Canada in winter.
We’ve got a much more mundane bird, but still unusual, under our feeders – a red-winged blackbird. It appeared on 12/26 and continues as of 1/1. Red-wings are perhaps the most abundant bird in North America, but typically winter only as far north as the southern counties of our state, and then continue as far south as Central America. What this fellow is doing under our feeders is perplexing, since red-wings are primarily ground feeders and ordinarily the Northwoods has too much snow for such behavior. But he seems to be doing fine on a diet of sunflower seeds, so we’ll see what transpires.
The Minocqua Christmas Bird Count took place on 12/20 and tallied 24 species, a good number given the foggy and misty conditions we encountered that morning. Just to illustrate the wintering bird difference between northern Wisconsin counties like ours that experience a true winter and southern counties that may see snow but only briefly, the Madison Christmas Count tallied 94 species and 38,933 individual birds – they had more cardinals (665) than we had total birds (595) on our Manitowish Waters Count. On the other hand, they also had more starlings (2,369) and house sparrows (2,509) than we had total birds, so their diversity comes with some costs.
We’re doing a birding trip to southeastern Arizona in March, and our guide there said they counted 140 species on their Christmas Count! Of course, it was 65° there, while we had 13° here, and the birds very well know the difference.
Finally, Joe Heitz photographed bear tracks on 12/19 while walking along the edge of Irving Lake. November was colder than average, but December has proven to be much warmer than average. While the bear could simply have been disturbed from his/her den, it may also have been feeling the warmth.
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| photo by Joe Heitz |
Proof of Wolves Fishing
Researchers in Minnesota’s Voyageurs National Park have documented for the first time wolves hunting freshwater fish as a seasonal food source, and there’s video to prove it!
In April of 2017, one of the researchers quietly followed the signal from a collared wolf to a creek, and then hid in some shrubs to watch the wolf’s behaviors. For the next 15 minutes or so, he watched the wolf meander back and forth around the creek, periodically running into the creek, splashing around, and looking like it was eating something. After the wolf departed, he found fish scales and blood and guts all over the edges of the creek, as well as wolf scats full of fish scales and fish remains.The wolf had been hunting fish — spawning suckers — in the creek.
A year later, the researchers set up trail cameras at the creek and caught footage of the wolves fishing at night.Even more interesting, the video also captured wolves catching fish and not eating them right away, instead, storing them on the bank of the creek while they fished some more.
Wolves in coastal habitats in British Columbia and Alaska eat spawning salmon, but this is the first time wolves hunting freshwater fish have been directly observed.
The researchers have also learned a variety of other things about wolves, one of which is that wolves eat a lot of beavers. In fact, they found that beavers can constitute up to 42 percent of a pack's diet from April until October. Their preliminary data shows that, on average, one wolf in Voyageurs Park kills about six to eight beavers per year. But since individual wolves opportunistically vary their diet depending on what’s available, they found that one wolf didn’t eat any beavers at all, but one other wolf had eaten 28 beavers in one year.
Read more at:
Moose Study
A multi-year New Hampshire study begun in 2014 is ongoing to learn more about threats facing the moose population there. Moose aren’t on the verge of disappearing from New Hampshire, but they are declining, and they want to know why.
Researchers from the New Hampshire Fish and Game Department partnered with the University of New Hampshire to collar 45 moose cows and calves each year from 2014-2017, and 50 in 2018 (230 total). They then compared mortality and productivity from a New Hampshire study conducted in 2001-2006, versus the work done from 2014-2018. What they found was that winter ticks are causing increasingly negative impacts to adult cow productivity. Moose attempt to remove ticks by scratching, licking, and rubbing, often removing their hair at the same time, which can lead to secondary infections and hypothermia. Individual moose can carry 10,000 to 120,000 ticks. The moose that they found dead had an average of 47,000 on them.
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| photo by Dan Bergeron |
They further noted, “In addition, as our winters become consistently shorter, more ticks are surviving and calf mortality is remaining high. We are also seeing clear evidence that tick loads are directly correlated with both moose density and shorter winters.” Today, winter in most portions of New Hampshire is three weeks shorter than it was 30 years ago. Shorter winters are allowing parasites to thrive that were formerly killed by longer periods of winter weather.
Interestingly, they also found that “as our winters continue to shorten, it may be best for moose if they are held at much lower densities. Based on our own work, we know that ticks have far less impact when moose densities are 0.25/square mile or less.”
The researchers remind us that “the most important thing to remember is that moose are a northern species. They evolved in ways that allow them to live in cold climates, climates that normally kill ticks. As our weather changes and our winters continue to shorten, there is a whole host of parasites and diseases normally associated with southern climates that will be able to survive here. Our changing climate is fundamentally changing the environment’s ability to support many of our northern species, be they flora or fauna. If we want our northern species to remain here we must act now to halt and reverse the impacts of climate change.”
Snowy Owl Study
In a study just published in the International Journal of Avian Scienceentitled “Age composition of winter irruptive Snowy Owls in North America(Santonja et al. 2019),” the researchers found that “large winter irruptions at temperate latitudes are not the result of adults massively leaving the Arctic in search of food after a breeding failure but are more likely to be a consequence of good reproductive conditions in the Arctic that create a large pool of winter migrants.”
For many years, the accepted explanation for why snowy owls would appear in large numbers during a given winter was that starvation was driving them south. It turns out to be quite the opposite – an excellent breeding year sends the numerous juvenile snowy owls well south in search of wintering territory. There apparently isn’t enough wintering territory further north to support both adult owls and the juveniles.
Celestial Events
The new moon occurs on 1/5. The sun rises one minute earlier on 1/8, the first time since 6/11/18. Our day length is growing two minutes longer as of 1/9.
The year’s coldest days, on average, occur between 1/6 and 1/26, with a high of 21°F.
The year’s average coldest low temperatures occur between 1/6 and 1/29 at 3°F.
After dusk on 1/12, look for Mars 5 degrees north of the waxing crescent moon.
And hey, things are looking brighter – we receive over 9 hours of daylight on 1/13!
Thought for the Week
“We think of wind as the voice of winter, the wind and the moan of the trees and the swish of sleet and snow. But the ultimate voice, the timeless voice of winter, is the boom of the ice, and is one of the coldest voices there is . . . Ice, which split the mountains, carved the valleys, leveled the hills, must proclaim its strength. The ice rends itself in a primalconvulsion. The ice booms.” Hal Borland, Twelve Moons of the Year
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