NWA 12/27/13

A Northwoods Almanac for 12/27/13 – 1/9/14   

Snowy Owl Invasion

As of 12/21, the state tally for snowy owls had reached 116, with a number of other reports awaiting confirmation. While every winter brings a varying number of these arctic visitors to Wisconsin, this year snowies are staging a possibly historic irruption from the Great Lakes east to the Atlantic coast and as far south as North Carolina. One owl was even observed in sunny Bermuda 600 miles out in the Atlantic Ocean, while observers in Newfoundland counted over 200 owls along a single 25-mile stretch of road.

Within Wisconsin, large numbers of owls have been seen along the Lake Michigan shoreline. An astonishing 11 birds had been observed at lower Green Bay by early December, with a much smaller representation of snowies inland, and virtually none in western Wisconsin and into Minnesota.

For some reason, the snowies are all heading east. The irruption has been centered in the northeastern states with the New York Port Authority reporting that between JFK, LaGuardia, and Newark airports, five snowy owls had been struck by planes in two weeks. The JFK Airport staff wasn’t impressed by their beauty and shot another three a few weeks ago, raising a din of protest in the birding community. Safety vs. rare birds creates some tough choices, though there were non-lethal methods of moving the birds.

December is often the month of peak snowy owl movements in Wisconsin. Since snowy owls nest on the wide open Arctic tundra with nary a tree in sight, when they migrate south they typically concentrate along open areas like coastal beaches, harbors, and breakwalls, or inland in open grasslands, agricultural fields, and large wetland complexes. Airports can be hotspots as can vast expanses of ice, which look a lot like the tundra.

Snowies are sometimes active throughout daylight hours, but most tend to sit tight and then become active around dusk and dawn. They’re not a night-hunting owl given that dark is an unusual occurrence during an Arctic summer!

             In the winter of 2005 - 2006, at least 150 Snowy Owls were reported/observed in Wisconsin, again mostly along the Great Lakes coasts, but this year may easily break that record.

Snowies are thought to move south primarily when their prey base of lemmings crashes. Lemming populations ebb and flow in roughly four-year cycles for reasons that are poorly understood. When the mouse-like rodents abound, a snowy owl might take 1,600 in a year, or about 190 pounds of lemming. More food means better nesting success and more owlets. A great lemming year can stimulate a strong push south when too many juvenile owls can overwhelm the tundra ecosystem. Lean lemming years trigger crashes in the owls and southward movement, which are termed irruptions.                                                So far this winter, mostly adults are being seen, so it appears the lemmings must have had a severe population crash.                                                                                                  To tell the age and gender of snowy owls, the dark speckled ones are the young. The larger ones are the females. Males and females of all ages may have more or less speckling but the tail tells all: males usually have 3 or less cross-stripes while females have 4 and often 5.

Christmas Bird Counts

            While snowies are showing up through much of Wisconsin, most other Canadian birds are staying north. We participated in two Christmas Bird Counts over the last several weeks, one in Minocqua and the other in Manitowish Waters, and the counts were remarkable for what we didn’t see, not what we saw. We were unable to find a single evening grosbeak, pine grosbeak, pine siskin, common redpoll, purple finch, white-winged crossbill, red crossbill, or bohemian waxwing, most of which we seen every winter, sometimes in substantial numbers.

            The only finch either in the woods or at feeders is the American goldfinch, and there are large flocks of those. Otherwise, both the woods and most people’s feeders are relatively quiet except for the nesting birds that remain the winter like black-capped chickadees, both nuthatches, blue jays, and the like.

            I don’t have the final numbers yet, but it looks like both counts will be record lows.

Robins in Winter

            Jim Schumacher near St. Germain sent me a photo of a robin eating crabapples in his yard on 12/5, but it hasn’t appeared since, nor did we see any on our Christmas counts. Robins eat a lot of fruit in fall and winter, and a few often remain up here if we have low snow accumulations.

But that’s certainly not the case this winter. We have lots of snow, and snow cover plays an important role in the presence of wintering robins throughout the Midwest. Snow and ice limit the availability of the fruits and berries that American robins depend on. Robin observations decrease sharply where snow depths are greater than 5 inches. In a recent Great Backyard Bird Count, there were only 3 reports of American robins in Wisconsin, Minnesota, and Michigan where snow cover exceeded 5 inches, while in areas where snow cover was less than 5 inches there were many more American Robins-- including some areas with flocks of up to 1200 individuals.

Perhaps almost as important is the influence of metropolitan areas on American robin distributions. The ornamental fruit trees (hawthorns, mountain ash, etc) planted in those cities provide vast amounts of food for overwintering robins. While we get excited to see one robin in the winter, robin roosts can be huge, sometimes including a quarter-million birds during winter. What are they eating when the ground is frozen and they can't get worms? Fruits. While some fruits are sweet and juicy in the summer and are eaten right away, the best winter berries are those that start out tasting too bitter to eat, and after freezing and thawing several times, become tastier. Some of the best include: bittersweet, snowberry, sumac, mountain ash, crabapple, hawthorn, highbush cranberry, dogwoods, and chokecherry.

So, the bottom line on robins is this: robins can survive blinding blizzards, ice storms, and nights as cold as 30 below zero. Their thick down feathers hold body heat in, and they produce body heat by shivering, so they can survive cold temperatures. It’s food availability that influences the number of American robins that overwinter in an area. When snow cover is high, making food difficult to find, American robins move farther south. When snow cover is low and food is more readily available, they seem to overwinter in northern locales in higher numbers.

Sightings – Badgers and Shrikes

            Frank Fassino in Mercer contacted me on 12/21 with the following story. His son Jeff lives just down the road from him and called him excitedly on the phone to look out his window – a badger was running toward his house. The badger had been down Jeff’s driveway, and walked around his house, before heading toward Frank’s place. Frank looked out the window and sure enough, a badger was running down his sidewalk, then up his driveway and onto his deck, all the time running and clearly hunting. Eventually the badger gave up on finding prey at Frank’s place and headed across Echo Lake for better pickings. Frank noted two things: one, the badger was able to stay on top of the snow the entire time because of the crust we’ve had so far this winter. And two, the badger was an amazingly fast runner for such a squat creature.

            Mary and I had a northern shrike visit our feeders on Dec. 9, and then on Dec. 22, just as we were about to head out for the Manitowish Waters Bird Count, Mary noticed the birds at the feeders had all frozen stockstill, a behavior usually indicating a predator nearby. Mary couldn’t find anything lurking in the trees, but came outside and told me what had happened, and as I was walking toward the car, there it was – a northern shrike in the top of one of our black ash trees right above our feeders.

Celestial Events

            While winter solstice has passed, our latest sunrises of the year occur from today, 12/27, through 1/7 when the sun finally starts setting a minute later for the first time since June 10. That will be a welcome moment indeed!!

            On 12/29, look before dawn for Saturn just one degree north of the crescent moon.

Celestial Websites

If you’re looking for a great website on all things celestial, there’s lots of them - try www.spaceweather.com, or www.heavens-above.com, or www.skyandtelescope.com.

End of the Year Thought

            If you have joy, you have everything.

Please share your outdoor sightings and thoughts: call me at 715-476-2828, drop me an e-mail at manitowish@centurytel.net, or snail-mail me at 4245N Hwy. 47, Mercer, WI 54547.