A Northwoods Almanac for 2/15 – 28, 2019  

Sightings

            Judith Bloom on Lake Tomahawk sent photos of several goldfinch drinking from her heated bird bath on a -10 degree morning. Providing water for birds in the winter is always a good idea. However, these small northern birds like goldfinch, redpolls, and pine siskins are astonishingly tough and show remarkable resilience to extreme cold. Goldfinch, when exposed in a study to severe cold (–94°F), remained homeothermic – kept a constant internal body temperature – for 6 to 8 hours. In the same study, half of the group of pine siskins remained homeothermic for 3 hours.

From captive studies in Alaska, common redpolls were able to survive at temperatures of -65°F compared with -88°F in hoary redpoll. Their adaptations to extreme cold include: fluffing feathers to retain heat, increasing their winter plumage by 31%, seeking shelter under the snow, restricting outer blood flow to retain core heat, selecting high-energy foods (primarily birch seed),storing food prior to darkness in their esophageal diverticula (they can hold 15% of their body weight in their crop!), increasing their digestive efficiency at extreme low temperatures, eating 31 to 42% of their body weight every day to keep their internal furnace stoked, and feeding at low light levels when other birds have called it a day.

On 2/5,Ed Marshall reported two common redpolls under his feeders in the Lac du Flambeau area. This would ordinarily not be worth reporting, but redpolls are rare this winter. We had one appear at our feeders on 2/9, along with nine goldfinches, which are also quite uncommon this winter. And we had one bohemian waxwing spend a few minutes in one of our crabapple trees on 2/7. You guessed it, bohemians are also hard to come by this winter.

By the way, common redpolls show a very consistent alternating pattern area of high numbers one year, and very few the next. So, I’m betting now that next winter our feeders will be loaded with them. 

            Bev Engstrom shared beautiful close-up color photos of a pileated woodpecker, a blue jay, and a female cardinal. I’ve attached them to this column, but to see them in their true intricate deatail, check the Northwoods Land Trust facebook page (https://www.facebook.com/NorthwoodsLandTrust/).

male pileated woodpecker photo by Bev Engstrom

blue jay photo by Bev Engstrom

female cardinal photo by Bev Engstrom

The Beauty of Ice

      In December of 1993, we had an ice storm that coated all the trees and shrubs and was gloriously beautiful. In my column that week, I quoted this passage written by Mark Twain in 1897; after our ice storm on 2/4, it applies perfectly again:

      "In time the trunk and every branch and twig are encased in hard, pure ice; so that the tree looks like a skeleton tree made all of glass . . . All are waiting; they know what is coming . . . The sun climbs higher, flooding the tree from its loftiest spread of branches to its lowest, turning it to a glory of white fire; then in a moment comes the great miracle, the miracle without its fellow in the Earth; a gust of wind sets every branch and twig to swaying, and in an instant turns the whole white tree into a spouting and spraying explosion of flashing gems of every conceivable color . . . a dancing and glancing world of rubies, emeralds, diamonds, sapphires, the most radiant spectacle, the divinest, the most exquisite, the most intoxicating vision of fire and color and unimaginable splendor that ever any eye has rested upon in this world, or will ever rest upon outside the gates of heaven."

Snow and Ice Loading

            Eight to 10 inches of snow fell on 2/7, our best snowstorm of this winter season so far, though the trees may have had a far different view, and we’re receiving another 6 to 10 inches as I write this on 2/12. Our ice storm in early February formed a crust on top of the snow that made walking difficult, but had also encased and weighed down the branches of every tree and shrub in the woods. The added weight of our recent snows to that ice collapsed many smaller saplings, bending them completely over into a croquet hoop. 

            I always worry about whether trees can spring back after an event like this, but northern trees have adapted over thousands of years to freezing rain, ice-loading, and heavy wet snow. Simply put, trees not adapted to periodic snow and ice loading don’t live here. Still, branches can break, tops can be snapped off, and trunks can sometimes be bowed over long enough to retain that form.

Our conifers, despite holding on to most of their needles, simply bend or fold their branches like an umbrella to shrug off the snow. Our deciduous trees, on the other hand, drop their leaves in part as an adaptation to heavy snow loads, but still must try to stand rigid and not break under heavy snows. Some tree species like red oak and ironwood tend to retain some of their leaves throughout winter, not the best of ideas relative to ice and snow, and are said to be marcescent.

Freezing rain is a different animal and can really tear off conifer needles and limbs. We’ve been trying to release some conifers from all the ice, but their needles simply break off in our hands. We’ll have to wait until the sun can do its work.

Great Backyard Bird Count

The 22nd annual Great Backyard Bird Count will be held today, Friday, February 15, through Monday, February 18. Participants are asked to count birds for as little as 15 minutes (or as long as you like) on one or more days of the four-day event and report their sightings online. Anyone can take part, from beginning bird watchers to experts, and you can participate from your backyard, or anywhere in the world. Last year, more than 160,000 participants submitted their bird observations online, creating the largest instantaneous snapshot of global bird populations ever recorded. For more information, visit http://gbbc.birdcount.org. 

Nesting Birds!

            Late February marks the earliest time for birds in our area to be nesting, and in this case, only two species – great horned owls and gray jays. I think they’re out of their minds, but their individual success as a species says all that needs to be said.  

Female great horned owls are able to maintain their eggs at a consistent incubating temperature near 98°F, even when outside temperatures are below -27°F. The eggs themselves are mighty tough, too. In one study, the eggs withstood the female’s absence for 20 min at -13°F when the female joined her mate to hoot at a neighboring male. 

The female is the only one to incubate, while the male is charged with bringing her food at intervals throughout the 30+ day incubation – a fair trade-off it seems.

            Canada jays nest during late winter in cold, snowy, and limited food conditions, incubating their eggs at temperatures as low as -22°F. Nestlings are typically being fed when lakes are still frozen and the ground is still snow-covered, and they’ll fledge before 80% of our other migratory birds have returned. 

newly hatched Canada jay photo by Dan Strickland

            Why risk such an early nesting? One thought is that since adult gray jays store food throughout the fall to sustain them through the winter, early nesting allows their young-of-the-year to have more time to learn how to store food in their wintering territories, lessening the risk of starvation. Another thought recognizes that the young fledge early and are feeding themselves by 41 days after hatching – almost always by May. Having the young out on their own early in the season gives the adults more time to gather and store the food they will need to survive the winter.

            I still think both species are half a bubble off plumb, but clearly they have adapted their behaviors over thousands of years, and, remarkably enough, they work! I’m in awe at their resilience.

2018 Fourth Warmest Year on Record

In its annual climate summary (see https://www.ncdc.noaa.gov/sotc/global/201813) NOAA’s National Centers for Environmental Information and NASA both reported that in 2018 Earth experienced its fourth warmest surface temperature in records going back to 1880. The five warmest years on record are the now the past five years—2016, 2015, 2017, 2018, and 2014, in that order.

The 2018 temperatures were slightly cooler than the previous three years, since the year began with La Niña conditions. During a La Niña, the large amount of cooler-than-average water in the tropical Pacific tends to decrease global temperatures. 

Celestial Events

            On 2/18, look before dawn for Venus one degree above Saturn.

            The full moon occurs on 2/19. This is the closest and largest full moon of the year, even larger than our January lunar eclipse moon. It will be about 14% closer and 30% brighter than the most distant full moon, and thus is tabbed the “supermoon.”  

            February 20 marks the 57^thanniversary of John Glenn as the first American to orbit the Earth. Glenn orbited three times in less than 5 hours in the Mercury spacecraft “Friendship 7.”

            Days are getting longer – we’re up to 11 hours of sunlight as of 2/27! Look in the early morning for Jupiter about two degrees below the waning gibbous moon.

Thought for the Week 

            “February is a whimsical month that can smother us in snow or set the sap to flowing, paralyze us with sleet or brim the brooks. Its days are as long as October’s, but its nights can be colder than December’s . . . When it goes we usually bid it a glad goodbye.” – Hal Borland, in Twelve Moons of the Year

A Northwoods Almanac for 2/1 – 2/14, 2019 

Why Extreme Cold Is Good

            January came in like a lamb, but certainly went out like a lion. While our recent spate of very cold temperatures is painful on our bodies, our car batteries, and our heating bills, these temperatures are nothing out of the ordinary for our area, and more importantly, are actually a very good thing. 

Yes, I said very good. Have I lost my mind? Well, that’s long been debatable, but, yes, cold is good! Why? Because extreme cold has the potential to beat back some of the invasive insects that are threatening northern tree and plant species.

For instance: The hemlock woolly adelgid (pronounced a-DEL-jid), a native of Asia, is only 1/32 inch long – perhaps the size of a period in one of these sentences – but has created an Armageddon for Eastern hemlocks. The adelgids feed on the sap at the base of hemlock needles, disrupting the nutrient flow and causing the needles to fall off. Without needles, the tree starves to death, usually within three to five years of the initial attack. White, woolly masses, which resemble tiny cotton balls at the bases of hemlock needles, indicate an infested tree.    

         

Without any native predators to keep it in check, this tiny aphid-like insect spreads at an average rate of 15 to 20 miles per year, blown by winds, carried by birds and other wildlife, and transported by infested nursery stock. As of 2018, it had killed or caused extensive declines in millions of hemlocks in eighteen states from Georgia to Maine, and has edged its way west into Ohio. This tiny, aphid-like insect now threatens more than 150 million hemlock trees in Michigan forests, and will eventually work its way into Wisconsin. 

But here’s the key. These insects are unique because they feed throughout the winter. If temperatures get cold enough, a high proportion of the insects can be killed. Adelgids use a process called supercooling, equivalent to antifreeze in a radiator, to survive the winter. But their antifreeze begins to fail at -5°F, and then they start to die. 

Researchers say that only the most northern stands of hemlock and those at the higher elevations in its northern distribution may ultimately escape the adelgids. That’s northern Wisconsin, but our hemlocks will only survive if we maintain extremes of cold.

Likewise, emerald ash borer (EAB), an Asian insect first identified in 2002, has become the most destructive forest insect to ever invade the U.S. As of 2018, populations of emerald ash borer have been found in 31 states, along with Ontario and Quebec, and the insect continues its march westward. Across Wisconsin, 48 counties are now under quarantine. 

            The best deterrent to EAB currently is severe cold. The larvae can supercool, but they die if they freeze. A 2010 study in Minnesota showed that 5% of the insects die at 0°F, 34% at -10°F, 79% at -20°F, and 98% at -30°F. That’s great news, but the larvae spend the winter under the bark of trees where they may be insulated by the bark itself – temperatures under the bark can be 2 to 7°F warmer than the air temperature. However, prolonged cold well below zero minimizes the insulating effect of bark.

Many other insect species have expanded their range northward in recent years. In the Pinelands in southern New Jersey, state foresters are battling the southern pine beetle. The beetle can tunnel through a tree’s bark, eating a layer of tissue that supplies the tree with critical nutrients – it’s killed millions of acres of pines in southern forests. Until recently, the beetles, which are native to the southern United States, did not survive north of Delaware, because of the cold. But that has changed as winters have turned milder. Efforts are underway to quell a large outbreak in Long Island's pine barrens and monitoring traps have caught beetles as far north as New England. The insect could reach Nova Scotia by 2020 and eventually infect forests from the upper Midwest to Maine.

There are a host of other ecological reasons to celebrate extreme cold temperatures, but the bottom line is that these cold temperatures are what make the North the North. Please understand that I, along with nearly all you, don’t enjoy this level of cold – I like it warmer, too! On these below zero days, we all spend inordinate amounts of time close to our wood stoves. But the North Country needs these extremes of cold. Be grateful, however much shivering you may be doing. The extreme cold typically only lasts a few weeks, but it can make all the difference.

Groundhog Day

Speaking of cold and how organisms deal with cold, groundhogs, or as we know them – woodchucks – are currently in deep hibernation. Waking up a woodchuck in the Northwoods on Groundhog Day would be a very slow process. Their body temperature drops to as low as 35 degrees, their heart rate falls to 4 to10 beats per minute, and their breathing rate falls to one breath every six minutes. These critters are knocked out for the duration of winter in northern Wisconsin, so while some may be awake looking for their shadow in Pennsylvania, there won’t be any wandering around here. 

2018 Deer Harvest Preliminary Numbers

Bow hunters registered 86,805 deer. Gun hunters (nine-day gun, muzzleloader, youth, December antlerless and Holiday Hunt) registered 239,296. Total: 326,101.

Ruffed Grouse and Fast Food

Grouse seldom dilly-dally over their meals – researchers say 20 minutes of foraging on buds will sustain them all day. They eat quickly, store the consumed food in their crop – a wide portion of their esophagus –  and digest it later at their leisure, under cover and away from danger. Grouse have a multi-chambered stomach and with the aid of both gravel to grind-up the buds and microorganisms to break down the cellulose, they enjoy their meal slowly, but not at the original table.

Sightings – Saw-whet and Barred Owl Eating Voles, Ice-up, Lack of Birds

            Debbie and Randy Augustinak in Land O’Lakes sent me this note on 1/16: “We’ve been fishing quite often lately and decided to place a trail cam on the leftovers . . .  The voles have been dining on the fish at night, and the owls have been dining on the voles!” They attached several videos from the trail cam showing a bald eagle eating the fish, and then a barred owl and a saw-whet owl eating the voles. 

I’m particularly pleased to see the video of the saw-whet because it’s always unclear if saw-whets remain the winter up here. Bird banding stations like the one at Whitefish Point Bird Observatory near Paradise, Michigan, record significant numbers of saw-whet’s migrating south. This October they banded 58 saw-whets. At the Thunder Cape Bird Observatory near Thunder Bay Ontario, they regularly band over 300 saw-whets migrating through every fall.

            Some saw-whets, however, winter-over in our area. We hear the males singing almost every spring, but they don’t sing in the winter, and they’re so small and secretive that they are virtually impossible to see. So, how many remain over the winter, and why some do and some don’t is very unclear. 

The Manitowish River below our house completely froze on January 10^th, the latest freeze-up we’ve seen in our 34 years of record keeping here, though our records are incomplete. Average ice-up date is late November.

            Two vehicles went through lake ice in the Mercer area over the last two weeks, demonstrating that temperatures below zero don’t guarantee ice is always safe, particularly where a river current runs through a lake.

            Even with our very cold temperatures in late January, our bird feeders remain very quiet. Usually that’s THE time for birds to appear at feeders – periods of extreme cold. But not this winter. Three pine siskins and four goldfinches showed up briefly at our feeders, but have moved on. 

            Interestingly, this is a pattern throughout much of the state as evidenced by postings on the Wisconsin BirdNet decrying how few backyard birds are being seen. Bev Engstrom, however, did find some bohemian waxwings and pine grosbeaks in the Rhinelander area and sent some exceptional pictures of them. And Greg Bassett in the Hazelhurst area sent along a photo of a pileated and a red-headed woodpecker at his feeder.

bohemian waxwing photo by Bev Engstrom

Celestial Events

            For February planet watching, look after dusk for Mars high in the southwest. Before dawn, look for brilliant Venus low in the southeast, Jupiter in the south-southeast, and Saturn also in the southeast.

            On 2/2, look for Saturn just below the waning crescent moon. February 3 marks the mid-season point between winter solstice and spring equinox. The new moon occurs on 2/4. By 2/7, we’ll be receiving 10 hours of daylight, well up from the 8 hours and 39 minutes we were given on winter solstice.

Thought for the Week

“The human race is challenged more than ever before to demonstrate our mastery not over nature but of ourselves.” – Rachel Carson, written in 1962 and still apropos today.