Sunday, May 20, 2012

NWA 4/27 - 5/10, 2012


A Northwoods Almanac for April 27 – May 10, 2012  

Sightings
4/4: Lisa Anderson reported a FOY (first-of-year) yellow-bellied sapsucker in her yard in Lake Tomahawk.
4/6: Pete and Carolyn Dring observed solitary bees all over their yard near Land O’Lakes.
 4/10: Carne Andrews and Katie Foley observed a FOY male Eastern Towhee.
4/13: Pat Schwai and her husband Rick successfully recovered a yellow-bellied sapsucker that hit the garage. Rick found him face down. The bird had a pebble in his eye and dried blood on his beak. Pat held him upright for 30 minutes before transferring him to a recovery box, where it still took him another hour before he could get his bearings and fly away. Pat and Rick also saw their FOY hermit thrush.
4/14: Mark Pflieger saw a FOY male rose-breasted grosbeak, an exceptionally early date – we usually don’t see our first one until around Mother’s Day.
4/15: Leatherleaf was in bloom by the tens of thousands in the bogs.
4/15: Carne Andrews and Katie Foley watched a sharp-shinned hawk perch on their deck eyeing the bird feeders. It was seen again the next day hunting for lunch near the feeders and chasing smaller birds in and out of the surrounding trees.
4/15: Dan Carney observed ruby-crowned kinglets in Hazelhurst.
4/16: Bob & Karen Dalle Ave in Hazelhurst observed a FOY beautiful indigo bunting sitting on a high stump right outside their living room window. Again, this is an exceptionally early sighting – Mother’s Day is the norm.
4/16: John Randolph saw two hermit thrushes on the parking lot of the Bolger Lake boat landing, and another in the front lawn of a neighbor, despite the light snow and chilly north wind.
4/17: John Werth watched a mink on their pier trying to get the fish guts from a platform feeder. John noted, “Amazing because it is on a steel post! Gale saw him make the leap!”
4/18: A Cooper’s hawk chased a mourning dove into one of our windows, killing the mourning dove on impact. The hawk flew up into a nearby tree, but never came back for it.
4/20: Judith Bloom on Lake Tomahawk photographed a pair of wood ducks in a pond on their property. She noted, “At times there will be four wood ducks and at least three or four drake mallards all in the pond along with a hooded merganser. We think the hen merganser is nesting in a nest box. This is the longest we’ve had the wood ducks stick around and we are so hoping to see ducklings.”
4/20: Ed Hunter on Round Lake in the Pike Lake Chain has a ring-necked pheasant strutting around his property and chasing his car. Ed figures the red fox that also frequents his property will likely be the ultimate beneficiary of the pheasant’s presence.
4/21: Hepatica was in bloom in the Frog Lake State Natural Area.
4/22: Juneberries came into flower. It’s such an early date for these to be flowering that we may actually have Juneberries ripe in June rather than July!
  
Dark-eyed Juncos and Fox Sparrows
            Numerous dark-eyed juncos and fox sparrows currently are vying for seed at our feeders with an array of purple finches, goldfinches, tree and white-throated sparrows, mourning doves, red-winged blackbirds, and grackles. The fox sparrows will soon pick-up and head far up into northern Canada and the Arctic to begin nesting. So will most of the dark-eyed juncos. But if you look at the junco’s range map, northern Wisconsin delineates the southernmost edge of their nesting territory, so some will stay behind to enjoy our comparative tropical heat.
            When we birded earlier in the month in southeastern Arizona, we were delighted to see a yellow-eyed junco, a Central American species that barely makes it way over the Mexican border. We saw the bird at about 6,000 feet elevation in some Ponderosa pines as we drove up Mt. Lemon near Tucson. Most yellow-eyed juncos are found above 6,000 feet in open coniferous forests, so we just happened to be in the right habitat at the right height.
            Juncos and sparrows have in common their foraging for seeds on the ground. Before spring migration is over, 11 species of sparrows will have returned (American tree, song, swamp, white-throated, chipping, clay-colored, Le Conte’s, Savannah, field, vesper, and Lincoln’s), all of which actively search the ground for seeds as well as eat insects. Juncos are also classified by ornithologists within the family “new world sparrows” as are towhees, longspurs, and snow buntings.
            I enjoy watching fox sparrows do “double-scratch” foraging. In one quick sequence, they position their head directly over the area being scratched, then hop forward with both feet, then sweep backward with both feet, kicking debris out from underneath themselves to reveal food, and then quickly returning to a normal standing position.           

Magnetic Migration
            How birds navigate just became more mysterious. For over a decade, birds were thought to use magnetic fields to guide their migration using magnetite in their beak tissue. However, Researchers from Austria, France, Australia, and England, writing in a new study in the journal Nature, report that iron-rich cells in the bills of pigeons are in fact specialized white blood cells called macrophages.
"The mystery of how animals detect magnetic fields has just got more mysterious," said study leader Dave Keays of the Institute of Molecular Pathology in Vienna. "We had hoped to find magnetic nerve cells, but unexpectedly we found thousands of macrophages, each filled with tiny balls of iron."
Each spring, hundreds of millions of migrating birds utilize an array of navigational tools including the position of the sun, the position of stars, landscape features, and magnetic fields. The returning hummingbirds that will soon show up at your feeders likely will use magnetic fields at least in part to navigate precisely to your home once again. Remarkably, scientists are still quite uncertain how they do it.

Low Water Levels on the Manitowish River
            It’s a very dry spring, and water levels on the Manitowish River are as low as we’ve seen them in our 28 years here. We paddled the river on 4/14 and noted three beaver lodges where the entrance holes, normally well below water, were a foot or more out of the water.
            The Manitowish Chain of Lakes is filling up. Bob Kovar on Wild Rice Lake reported watching a Canada goose sitting on eggs as of April 12, only to have the water level continue to rise and eventually submerge the nest on 4/22. The goose tried for several days to bring up plant material to raise the nest, but to no avail and finally abandoned the nest.
           
Looking Back at March
National temperature records for March were not just broken, they were cooked.
Temperatures in the lower 48 states were 8.6 degrees F above normal for March, and 6 degrees F higher than average for the first three months of the year, according to the National Oceanic and Atmospheric Administration, far exceeding the old records dating from 1895.
The atypical heat goes back before 2012. The U.S. winter of 2010-2011 was slightly cooler than normal and one of the snowiest in recent years, but after that things started heating up. The summer of 2011 was the second warmest summer on record.
The winter that just ended, which in some places was called the year without winter, was the fourth warmest on record. Since last April, it has been the hottest 12-month stretch on record.
But the month where the warmth turned especially unusual in the United States was March. Normally, March averages 42.5 degrees across the country, but this year, the average was 51.1, which is closer to the average for April. In March, at least 7,775 weather stations across the nation broke daily high temperature records, and another 7,517 broke records for evening heat.
Global warming? We always must keep in mind that one year is simply data, while many decades of data may show decisive trends. In a recent paper submitted to the journal Proceedings of the National Academy of Sciences, NASA climate scientist James Hansen shows that heat extremes aren't just increasing but happening far more often than scientists thought. What used to be a 1-in-400 hot temperature record is now a 1 in 10 occurrence, essentially 40 times more likely.
            I shy away from politics in this column, but this isn’t about politics – it’s about science. To hear Dr. Hansen speak on this topic, go to: www.youtube.com/watch?v=fWInyaMWBY8

Celestial Events
            For May planet watching: look at dusk for Venus, exceptionally bright at -4.7 magnitude, in the northwest, for Mars high in the south, and for Saturn in the southeast. Before dawn, look for Saturn setting in the west, and for Mercury early in the month very low in the east.
            The full moon, known to native tribes as the “flower” or “planting” moon, occurs on May 5. This will be the year’s closest (221,800 miles from the Earth) and thus largest full moon. Unfortunately, the peak Eta Aqarid meteor shower (averages 20-40 meteors/hr) also occurs that night and will be effectively washed out by the brilliant moon. May 5 also marks the midway point between the spring equinox and summer solstice. Our days are growing longer by two minutes per day.

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