NWA 2/7/14

A Northwoods Almanac for Feb. 7-20, 2014 

Sightings – Varied Thrush

Kathy Cieszynski in Eagle River has had a varied thrush visiting her feeders throughout January. Kathy’s is the first sighting of a varied thrush that I am aware of in our area this winter. Varied thrushes are similar in size and shape to a robin, but are a very distinctive orange and black. They 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,” wrote W. L. Dawson in his 1923 book, The Birds of California.

This shy bird breeds most commonly in mature and old-growth forests. Its distinctive song—a slow series of single drawn-out notes at different pitches—“is as perfectly the voice of the cool, dark, peaceful solitude which the bird chooses for its home as could be imagined,” at least according to L. A. Fuertes, an early American ornithologist and illustrator.

Most individuals winter along the Pacific Coast, with occasional individuals seen throughout the western United States and, during irruption years, across the United States and Canada. In Minnesota and Wisconsin, most sightings occur along a 120-mile-wide corridor which corresponds with the southern extent of coniferous forest in both states.

Sightings – Barred Owl

In the pre-dawn of 1/28, Mary Guenther in Minocqua peered out her bedroom window and thought she was seeing a branch on the ground beneath their bird feeders. Instead, “Turns out it was this beautiful barred owl feasting on a rabbit, just sitting on its prey, and occasionally taking a bite.”

Mary and her husband observed the owl until mid-afternoon when it finally flew away. She noted, “The birds don't seem to be bothered by its presence, but the squirrels are reluctant to get too close … Throughout the day it appeared to rest (eyes closed), eat and check out its surroundings. The rabbit's head is missing, but the body, which it was sitting on, is still there.”

Sightings – Chukar!

Back on November 25, Marylyne Haag and her daughter Wendi Neupert sent me a picture of a chukar that was outside Marylyne’s apartment in Boulder Junction. Their comment, “Seems a long way from home,” was highly apropos given that chukars are found in the Great Basin of the western United States where steep rocky mountainous terrain harbors a mixture of brush, grasses, and forbs.

The Chukar Partridge was first introduced into North America in 1893, when 5 pairs were shipped to Illinois from Karachi, India (now Pakistan). Between 1931 and 1970, another roughly 795,000 Chukars were released in 41 states in the U.S. (including Hawaii), and 10,600 birds were released in 6 Canadian provinces.

The Chukar has become a favorite of western sportsmen and ranks first in harvest among upland game birds in Nevada and Oregon, second in Washington, and third in Idaho.

Chukars are a medium-sized partridge with a distinctive black line through their forehead, eyes, and down their neck. The practice of releasing captive-bred Chukars for sport shooting is fairly common throughout North America, and I suspect someone training their hunting dogs in the area released this one, and it got away.

Sightings – Northern Shrike

Sharon Lintereur in Lake Tomahawk reported that on 1/26 she watched as a northern shrike “went after a white-breasted nuthatch and won. It was a pretty spectacular sight. The nuthatch was sitting on the feeder with its bill straight up in the air being very still when the shrike went in for the kill.”

Over the years, Mary and I have watched birds many times freeze stock-still on our feeders, and we’ve often been able to then spot a predator nearby. It sounds like the strategy didn’t work for the white-breasted nuthatch at the Lintereur house.

Ice Caves on Lake Superior

You may have noticed that it’s been a bit chilly this winter, one positive result of which is that the ice caves on the Bayfield peninsula are accessible for the first time since 2009. They’ve even made the national news several times in the last few weeks. On 1/24, Phil and Nancy Williams journeyed there to hike the rough 2-mile trail to the caves. They noted, “There were hundreds of people, and we had to park about 1/2 mile from the lake. Yesterday was the warmest day of the week at 20F with a strong wind that made the trip back seem longer.” Nevertheless, they loved the trip and sent me several pictures, one of which I’ve included in today’s column.

            Seeps of melting snow, spring water from the rocky sandstone cliffs, and icy mists off the open lake congeal in formations that often seem to defy the laws of nature. Colors vary from turquoise to blue to green to rust to orange, and the shapes diverge wildly depending on the conditions when the ice was formed.

            Bundle up and make the trip if you can. Some would say it’s a pilgrimage required of everyone living in the Northwoods.

Hairy Woodpecker Enormous Beak

            Gary Kmiecik stopped by to show me a male hairy woodpecker that had died when it hit one of his windows. What was unusual about this bird was the size of his beak! It was 2.25 inches long, nearly twice the length of the normal hairy’s beak which averages 1.3 inches. Gary had watched this bird at his feeders for weeks beforehand, and noted that the bird often had to tilt his head upward to eat a seed. Normally, a woodpecker’s tongue can be extended beyond its bill to get at insects behind bark or in a tree hole, but it appeared that this one’s tongue was normal-sized and  couldn’t reach that far.

            We both felt that this was a mutation, one that if it offered some adaptive advantage, might be something carried over into future generations. But without the tongue also increasing in size, the bill appeared to us to be a hindrance rather than an asset. I also wonder how well it could fly, given that some perfect proportion of bill size to body size surely exists for this species of woodpecker. Bigger isn’t always better by any means - everything always has to be balanced, or the loss exceeds the benefit.

Snow Acoustics

A heavy snowfall seems to muffle sound, taking away the hard edges of even semi-trucks passing by, and leaving an overall extraordinary calm. Is there any science behind this? You bet. The pores in the snow cover are responsible for the quiet conditions, says The Snow Interest Group, a large group of scientists sponsored by the Cold Regions Research/Engineering Laboratory and the U.S. Army. Their research shows, “When acoustic waves travel horizontally above the snow, the increased pressure of the wave momentarily pushes some air into the pores. This air returns to the atmosphere after the wave passes, but some energy has been lost from friction and thermal effects. Over a short distance, this mechanism can significantly reduce the sound energy in the acoustic wave.” This contrasts to what occurs over acoustically hard surfaces, like concrete or water. Sound carries very well over these surfaces, as anyone on a lakeshore knows when clearly hearing a conversation on the other side of the lake. The snow scientists have tested their theory by firing a pistol from exactly the same spot and the same distance away in summer and winter, and recording the results. In the summer the pistol shot was a loud "bang" as one would expect, but in winter with snow on the ground, the pistol made more of a muffled "whoomp" sound.

Flying Squirrels

            Bob Kovar in Manitowish Waters sent me a photo of the family of flying squirrels that visit his seed feeders every night, arriving and leaving at the same times like clockwork. We have at least three flying squirrels visiting our feeders as well, but they are far more irregular in their appearance.

            When we watch them, they seem almost impossibly fast. They’re present one moment, gone in a flash, then return in an equally improbable blink.

Wisconsin boasts two species of flying squirrels, the southern flying squirrel (Glaucomys volans), and the northern flying squirrel (Glaucomys sabrinus). The southern flying squirrel is about the size of a chipmunk, about nine inches long, and the northern flying squirrel is slightly larger, almost 11 inches, including the wide flattened tail which is nearly half as long as the flying squirrel. Both only weigh two to three ounces.

Flying squirrels are the only nocturnal squirrels in Wisconsin. Their large, dark eyes are adapted for night vision, so they see as well at night as humans can see during the day. They frequently visit bird feeders, and lights at the feeders don’t seem to bother them, so one can often easily watch the flying squirrel's antics at night.

Celestial Events

            February 2^nd may have marked Groundhog Day to the National Press, but more importantly, it was a cross-quarter day marking the midpoint between winter solstice and the spring (vernal) equinox. While we know we’re still in for lots of winter, the days are growing longer by three minutes each day, and by the end of the month, we’ll be receiving over 11 hours of daylight, a far cry from the meager 8 hours and 39 minutes we were rationed back on winter solstice. Hang in there!