A Northwoods Almanac for 2/16/18

A Northwoods Almanac for 2/16 – 3/1, 2018

Sightings – Northern Shrike and White-throated Sparrow

Nancy Anderson spotted a northern shrike in her yard on 2/3 and noted: “We have many common redpolls at this time here in Lac du Flambeau, so we're thinking hunting is good for this predatory song bird.” She’s right. Around one’s home, northern shrikes are a short-lived thrill to spot. While they’re uncommon and beautiful, they are there for one reason only – to scout your feeders for their next meal.

photo by Nancy Anderson

Their Latin name, Lanius excubitor, means “butcher watchman,” a fitting tribute to their skill set, because they typically sit and wait to spot prey from an exposed hunting perch. We’ve watched them sit motionless above one of our feeders for many minutes waiting for a mouse or vole to venture from a hole.

The literature says they have the ability to spot motionless birds “frozen” on branches and to capture them before they move, which is not good news for the many songbirds that utilize this defense. They’re not strong direct flyers, but they don’t give up easily, often following prey into thick bushes. They’re also known to take down birds larger than themselves, including robins, jays, and doves.

They kill birds and other vertebrates by biting the nape of the neck and “disarticulating cervical vertebrae.” Northern shrikes have bilateral, subterminal tomial teeth on their upper bill which appear to penetrate between adjacent vertebrae, quickly damaging the prey’s nerve cord, thus paralyzing and killing it.

Bilateral: both sides. Subterminal: almost at the end. Tomial: a notch on the edge of the beak. They’re not “teeth” since no bird has teeth, but they’re like a tooth along each side of the beak. These “teeth” make for a prey’s quick death, which as any hunter knows is a good thing.

There are frequent reports of shrikes killing in excess of their food requirements. Bird banders tell me of shrikes getting inside their traps and killing all the birds. But shrikes will store food, so they’re just harvesting what’s available for later use, no different than humans putting food in the refrigerator for later meals.

On another note, we have a single white-throated sparrow spending the winter at our feeders. As a ground feeder wintering in deep snow country, this white-throated sparrow has to be severely challenged to survive. I wish I could ask him why he didn’t migrate to a warmer climate with less snow back in November.

The white-throat’s winter diet is mostly grass and weed seeds, thus the need to winter further south. But they also eat fruits of sumac, grape, highbush cranberry, mountain ash, and rose hips, all of which (except sumac) we have in our yard, so perhaps that explains this lone male staying put.

 They also know how to dress for the winter – a white-throated sparrow has some 2,500 contour or body feathers in winter compared to summer's 1,500. So, the cold may not be too much of an issue for this little guy.

Update on the Clark’s Nutcracker

            Mary and I were able to visit with a very gracious couple in Oneida County who have had a Clark’s nutcracker visiting their yard since the first of the year. The nutcracker is drawn to a deer carcass they have hanging from a tree, as for that matter are chickadees, nuthatches, and other birds – fat equals high energy in a cold winter.

photo by John Bates

            As I wrote about in my last column, the nutcracker is a very rare visitor to Wisconsin, so this is a big deal in the birding world. The question that always arises when a bird is so far from its normal range is what will happen in the spring? Will the nutcracker know how to migrate back to its normal Rocky Mountain breeding habitat, or will it look around and say “What now?”

One day it will disappear from its winter restaurant, and unless banded and recovered, we’ll never know the end to the story.

Great Backyard Bird Count

The 21^st Great Backyard Bird Count (GBBC) will take place February 16 to 19. This global event provides an opportunity for bird enthusiasts to contribute important bird population data to scientists so they can record changes over time. To participate, bird watchers count the birds they see for at least 15 minutes on one or more days of the count, then enter their checklists at birdcount.org.

Over its 3-decade history, the GBBC has expanded from a 2-country count (U.S. and Canada) to a global event. During the first GBBC in 1998, bird watchers submitted about 13,500 checklists from the United States and Canada. Twenty years later in 2017, an estimated 240,418 bird watchers from more than 100 countries submitted 181,606 bird checklists and reported 6,259 species – more than half the known bird species in the world. 

The rules are easy:

Count birds for at least 15 minutes on any of the days or all: Feb 16, 17, 18, or 19.

Keep track of how long you counted and if you’re walking, how far you walked.

Go to your favorite spot or any spot. It doesn’t have to be a backyard – it can be anywhere.

Start a new count for each new place or time.

Enter your checklists at birdcount.org.

This can be as easy as you want it to be – lots of folks simply look out their windows and count their feeders from the warmth of their homes. And in the Northwoods in February, you’re likely to see more birds that way than taking a walk or driving around looking for birds. Our Christmas bird counts have proven this many times over. Please consider joining the count!

Nesting Has Begun!

            As hard as it may be to believe, several bird species should now be nesting. Both great horned owls and gray jays are known to be incubating eggs by late February. Gray Jays nest during late winter in cold, snowy, and apparently foodless conditions, with eggs incubated at temperatures as low as -22°F. Nest building can begin in February, with clutches initiated as early as Feb 22 in Algonquin Park, Ontario, which is almost exactly the latitude of Minocqua. Interestingly, second broods or replacement nests are not attempted in May or June, the breeding period used by other boreal passerines. Gray jay nestlings are being fed before 80% of our migratory birds have even returned.

For great horned owls, females are able to maintain their eggs at incubating temperatures near 98°F, even when the ambient temperature is more than 70° colder. They’re able to incubate eggs successfully when outside temperatures are below -27°F. In one study, the eggs withstood the absence of the incubating female for 20 minutes  at -13°F when the female joined her mate hooting at a neighboring male.

Winter Birdbaths

I was asked whether winter bird baths are a good idea or not. It’s been said that birds can get their feet wet in these baths, and then freeze to the metal rods on bird feeders. I have heard of this occurring on two occasions over the last 25 years, but that’s a pretty small percentage. My sense is that the advantages far outweigh the risks. After all, birds can get their feet wet in a host of other ways in the winter – we do have open water in many creeks, and dripping icicles are common drinking sites for birds – so, bird baths are not exposing birds to some novel occurrence.

The simplest way to provide water in winter is to set out a very shallow plastic pan at the same time each day, and bring it in when ice forms. If you want to keep a birdbath ice-free, some birdbaths come with built-in, thermostatically controlled heaters.

Some simple, common sense rules include never adding antifreeze to the birdbath – it’s poisonous to all animals. Don’t use a sugar solution, either: it can saturate and matt a bird’s feathers leaving it susceptible to hypothermia. Just use plain water.

It’s also important to change the water every day or two. Bathing birds may leave behind dirty feathers and droppings, making the bath increasingly unsanitary for other birds.

Celestial Events

            The new moon occurred yesterday, 2/15. Check the night sky tonight because this is the time of year when the brightest accumulation of stars can be seen annually. Look for constellations like Orion, Sirius, Gemini, Auriga, and Taurus, all of which contain first-magnitude stars.

            Venus rises before dawn late in the month in the southwest, and will climb higher and higher as the spring returns. For right now, however, the morning planets are Saturn, Mars, and Jupiter, all of which can be seen in the southeast before dawn.

            As of 2/27, we will be receiving over 11 hours of sunlight – hooray! It’s getting lighter every day.

            February has no full moon this year. The next full moon occurs on March 1, and like January, March will have two full moons, the second one occurring on 3/31.

Thought for the Week

            “We ourselves seldom comprehend the moment at hand. So, we turn to history, the one element of our lives it is possible to fix on. Or we turn to principle. Or we turn to nature. There we find, amid the silence and mystery, order and structure, the sense that life is not simply random.” – Paul Gruchow

A Northwoods Almanac for 2/2/18

A Northwoods Almanac for 2/2 – 2/15/2018  

White-Nose Syndrome Breakthrough?

In the never-ending list of reasons for why we need scientific research, scientists may have discovered a solution to combat the fungus that causes white-nose syndrome in bats.

The fungus, Pseudogymnoascus destructans, grows on the wings, snout and ears of hibernating bats, and disrupts them as they hibernate, causing them to wake up and burn the limited fat stores they need to survive winter.

However, the fungus is known to thrive only in cold, dark environments (such as caves) with a strict temperature range of 39 to 68 F, so it can only affect bats during hibernation.

A team from the U.S. Forest Service, U.S. Department of Agriculture and the University of New Hampshire recently conducted a genomic analysis on P. destructans and identified a potential “Achilles heel” – the fungus is highly sensitive to UV light. They found that a low dose exposure for just a few seconds of the UV light resulted in a 15 percent survival rate of the fungus, and a moderate dose led to just a one percent survival.

The trick now is determining how to best use the UV light throughout the winter on a large-scale without disrupting the animals’ hibernation.

Sightings – Clark’s Nutcracker!

            Dan Carney in Hazelhurst sent me a photo of a Clark’s nutcracker that was seen a few weeks ago pecking at a deer carcass on a farm near Tomahawk. Clark's nutcrackers inhabit the high mountain regions of the western United States and Canada, preferring coniferous forests dominated by large-seeded pines. So, seeing one in north central Wisconsin is a very rare event. The Wisconsin Society for Ornithology keeps records of rare bird sightings, and only five reports of Clark’s nutcrackers have been verified in Wisconsin, the last one in 1973 in Manitowoc.

photo by Pete Ventener

They’re known to eat carrion, insects, and small animals, however, they’re truly specialists on pine seeds. In fact, several pine species depend on nutcrackers for their seed dispersal and have evolved specialized cone and seed traits for this interaction, including whitebark, limber, Colorado piñon, single-leaf piñon, and southwestern white pines.

Clark’s nutcrackers cache vast numbers of seeds for the winter. In one study, nutcrackers stored 22,000 to 33,000 seeds of Colorado piñon pine, while in another study, two individuals hid 35,000 seeds and 98,000 seeds of whitebark pine respectively. Consider the incredible spatial memory they must have to then find all those seeds.

Clark’s nutcrackers were one of three new bird species described by Alexander Wilson from specimens collected during the historic Lewis and Clark expedition. Clark's Nutcracker was feeding on pine seeds and was mistaken for a woodpecker when first seen by Captain William Clark on August 22, 1805.

The last time Mary and I saw a Clark’s nutcracker was in March 2005 along the south rim of the Grand Canyon, a rather far cry from Tomahawk!

Sax-Zim Bog

Earlier in January, the North Lakeland Discovery Center Bird Club visited the Sax-Zim Bog in northeastern Minnesota and found 28 species of birds, including three species of owls – great gray, northern hawk, and snowy. They also observed other rare birds like a black-billed magpie and a black-backed woodpecker. Bird club member and ace photographer Mark Westphal took some superb photographs, of which I’ve shared two in this column – a great gray owl and a black-backed woodpecker.

photo by Mark Westphal

photo by Mark Westphal

Other Sightings

            It’s been an excellent winter for pine siskins, common redpolls, and pine grosbeaks. We have a flock of 20 pine grosbeaks consistently at our feeders, along with good numbers of siskins and redpolls. Many other folks are reporting large populations as well at their feeders of all three species. Missing in action continue to be purple finches, evening grosbeaks, and bohemian waxwings. 

Common redpolls only weigh around ½ ounce, and are astonishingly tough little birds. They breed worldwide in the boreal and taiga regions of the Arctic, so they come a very long way to share our winter backyards. In North America, they irrupt in large numbers only in alternating years and only in even-numbered years, with one exception, 1969. The irruption cycle is driven by a widespread failure in spruce and birch seed-crop production which forces these birds to winter farther south.

photo by Bev Engstrom

They are known to travel east and west during the winter as well. One redpoll banded in Michigan was subsequently recovered in eastern Siberia, while redpolls breeding in Alaska have been recorded wintering in the eastern U.S.

In captive studies, common redpolls in Alaska were able to survive at temperatures of minus 65°F, while hoary redpolls survived at minus 88°F. That seems impossible to me!

Conversely, redpolls can’t tolerate high temperatures. As temperatures warm, captive birds became less active, eat less, drink more, and pluck their body contour and down feathers. Thus, climate change doesn’t bode well for them.

             

Snow Statistics

The water equivalent of snow is more variable than most people realize. For instance, 10 inches of fresh snow can contain as little as 0.10 inches of water, or as much as 4 inches of water, depending on crystal structure, wind speed, temperature, and other factors. The majority of new snowfall in the United States, however, contains a water-to-snow ratio of between 4 percent and 10 percent.

Snapper Hibernation Crazy Facts

In the winter snapping turtles hibernate in shallow water, buried in the mud in places which don’t freeze to the bottom. During that time their body temperature is reduced to about 34°F, and they rarely move, although some have been observed moving under the ice. In northern areas, hibernating snapping turtles don’t breathe through their lungs for more than six months while under the ice. They can, however, get oxygen 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.

2017 Weather on the Record Books

According to NASA and the National Oceanic and Atmospheric Administration, last year was the second or third warmest year on record, depending on which agency’s records you examine, because each has its own method for its calculations. One warm year is not necessarily cause for concern, but the trend is. The past three years were the warmest three ever recorded, and seventeen of the 18 warmest years in the data have come since 2001. This decade is on track to be warmer than the 2000s, which were warmer than the 1990s.

Snowy Owl Update

            Four snowy owls are currently being followed by researchers in Wisconsin via their transmitters. Two are wintering close to one another in the Buena Vista grasslands in central Wisconsin. Although they have largely avoided each other, both have been perching on the same center-pivot irrigation rig at different times. The two young males have been sharing a large area, about 5,400 acres. One sticks to a core area of about 500 acres, while the other wraps around it while generally not intruding on it.

The other two snowies are on territories elsewhere in Wisconsin. One female is using a roughly 760-acre territory southwest of Green Bay, around which she moves a lot during the day. The other one, a male, has a bit more wanderlust, tracing a vaguely inverted J path north of Madison that stretches some 12 miles from end to end, and he’s more typically nocturnal in his movements.

Celestial Events

            February 3 marks the mid-point between winter solstice and spring equinox, though as we all know, spring equinox doesn’t mean spring is arriving up here. We’re up to 10 hours of daylight as of 2/7. On 2/8, look before dawn for Mars about 4 degrees south of the waning crescent moon. On 2/11, look before dawn for Saturn about 2 degrees south of the moon. New moon on 2/15.

Thought for the Week

            “Winter is not a season, it's an occupation.” – Sinclair Lewis