Monthly Archives: March 2013

Sunset at the Vernal Equinox

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When I awoke this morning, I heard that spring would officially arrive at 7:02 am.  Yes! Because I don’t have an exercise class scheduled on Wednesday evenings, I decided to visit the UMass Sunwheel for the 6 pm informational program.  All day, the sun went in and out of the clouds, but the sky was clear when I left work at 5.  About thirty of us braved the chill and lingering snow to gather around Professor Stephen Schneider of the UMass Astronomy Department.

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The Sunwheel, Professor Schneider explained, is a teaching tool in the 21st century, but for thousands of years this type of physical arrangement of markers had been used by many cultures as a calendar, in places as far-flung as England, Egypt, and South America.  It isn’t even that difficult to set up: one simply has to observe where the sun rises and where it sets.  In fact, that is how the UMass Sunwheel was constructed, by patient and careful observation (and plenty of help in transporting and placing the heavy granite stones).

At the Equinox, the sun rises due East and sets due West, the only days in the year that this is true.  All over the world on this day, the citizens of our planet experience 12 hours of daylight and 12 hours of night.  However, the movement of celestial bodies, or at any rate, the appearance of such movement, is place-specific, which means that the angles of the sun in the sky that we observe in Amherst are specific to our latitude (42.3804° N).  Because our latitude is almost half-way between the Equator and the North Pole, we see the sun at its highest point today at 48 degrees above the southern horizon.  At the North Pole on this day, the sun would be observed traveling from east to west on the horizon at 0 degrees, and at the Equator on this day, the sun would be observed traveling at a 90 degree angle to the horizon; at noon, it would be directly overhead.

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Although it wasn’t the focus of today’s program, Professor Schneider also told us a little bit about the Moonstones; by their position relative to the Sunstones, we can infer that the moon has a bigger tilt than the Earth, by about 5 degrees.  The newest stones are the two Starstones, placed to indicated the rising of Sirius and Aldebaran.  The stone below is one of them, but I’m not sure which.

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By this time I was shivering from the cold, but I did wait to see the sun sink beneath the horizon.  I took this picture at an angle because I didn’t want to stare directly into the sun.

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Here’s my final photo, taken from where I had parked my car.

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Welcome, Spring!

Eagles at Quabbin

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I live about twenty miles from the Visitors’ Center entrance to the Quabbin Reservoir, and in fact, I drive around the southern tip of the reservoir every day, as I travel to and from work.  It’s a marvelous place, this “accidental wilderness,” as they began calling it after it was created by erasing four Massachusetts towns from the map in 1939, in order to create a stable water supply for Boston, fifty miles to the east.

I don’t hike the trails very often, but today I drove out there shortly after lunch to walk along the top of the Winsor Dam and then attend a presentation on the resident bald eagle population.  Here I’m looking west from the top of the dam.

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Note the large patch of winter snow in the background.

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Although the sun shone brightly all day, it was very windy; the flags are flying straight out.

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At 2 pm, around 75 of us crowded into the Visitor Center conference room for a talk by Bill Dean, an avid outdoorsman and photographer who has been observing wildlife for many years.  He lives with his wife in Monson and has been photographing the Quabbin eagles for about seven years.  He started his talk with some common-sense advice about observing eagles: when they are incubating eggs, they are sensitive to disruption, so don’t try to get too close. He uses a  Nikon D-7000, with 16 megapixels and digiscoping capability (I think this means he uses a spotting scope).  He noted that you don’t need a DSLR but can get excellent photos with a point-and-shoot camera with optical zoom.

As we watched his slide show, with both still images and video, Bill provided a running commentary on bald eagle (Haliaeetus leucocephalus) lore.  Here are some interesting facts about our eagles:

  • Nests are huge, perhaps 6-8 feet across and 4 feet deep
  • Eggs are laid by the first week of March and incubate 35 days
  • Nestlings go through different sets of feathers with color changes
  • In July when the eaglets are between 10-14 weeks old, they leave the nest
  • Both parents feed the chicks, even into September
  • Eagles eat mostly fish but will also feed on other birds or even carrion
  • Keen eyesight allows them to spot prey a mile away
  • Wingspan of a mature adult is around 7 feet
  • Males and females have the same coloration, but females are much larger
  • By 5 years old they have the characteristic white head and white tail
  • Average lifespan of an eagle in the wild is 25 years

The Quabbin eagles are a wildlife recovery success story.  They were first re-introduced in 1982 when Mass Fisheries and Wildlife and its partners brought in two chicks from Michigan, nicknamed Betsy and Ross, and raised them in cages overlooking the Reservoir.  Since then, the resident population has been closely tracked and monitored.  I don’t have recent numbers for you, though I can report that 107 bald eagles were documented in Massachusetts in 2011, during the annual Midwinter Bald Eagle Survey, which is scheduled each January.  These are not counts of breeding pairs, however, as during the winter, the eagle population increases dramatically due to the influx of migrants from Canada, where due to the more northerly climate, the eagles can’t find enough food.

One of these days, I’m determined to see at least one bald eagle at the Quabbin in real life, and then I’ll upload a photo for you.  Happy St Patrick’s Day.  You can see me wearing green in Image 9.