Snows Fall

Folks on the Delmarva Peninsula have a delightful term for the seemingly out-of-nowhere arrival of tundra swans each autumn. They call it ‘swan fall’. Arriving from their breeding grounds in the upper reaches of the western Arctic, swans stage every December in the Dakotas and Lower Canada. They wait for the first strong Northwesterly winds and ride them all the way to the Atlantic coast. Overnight, baylets and creeks of the Chesapeake are graced by their elegant beauty. A line of swans, honking and laughing their way south, backlit by the full moon, is one of the more unforgettable sights you can witness in nature.

Snow geese are poor man’s swans. Slightly smaller than Canada geese, they are gleaming white with black wing tips. Moving in family groups of up to half a dozen, they form large flocks to feed on marsh grasses and newly sprouted winter rye in farm fields. Geese are birds trying to be sheep and will graze happily on anything green.


The snow geese in this area are almost exclusively Greater Snow Geese.(Chen caerulescens atlantica) as opposed to their smaller and more abundant Lesser Snow Goose (Chen caerulescens caerulescens) cousins. Lesser Snow Geese are rarely seen along the Atlantic, but very common along the Mississippi and Central flyways in the heart of North America.

Any flock of snow geese, Greater or Lesser, will contain a proportion of blue geese. Blue geese, with white heads and blue-gray bodies, were once thought to be a closely-related species and given the poetic scientific name Chen hyperborenis, meaning “goose from beyond the north wind”--this was before hardy explorers with an ornithological bent journeyed north to above the Arctic Circle and actually observed the birds on their nesting grounds. Blue and snow geese paired indiscriminately and broods had both snow and blue goslings. Blue geese were determined to be a genetic color variant or morph and the species name was retired. Blues and snows vary in relative proportions, depending on environmental factors favoring one morph or the other. Currently, snows seem to be in the ascendancy, with over 90% of the birds being the white morph.

Snow geese, due to their resemblance to swans, have been protected from hunting (nobody wants to shoot an angel by mistake), and populations, especially in the Lesser Snow Goose, have exploded to the point where over-grazing orgies (called eat-outs) at the nesting grounds are destroying the sparse vegetation, endangering the goose population as well as other species using the same tundra habitat. Increased bag limits and longer seasons for hunters seem causing some leveling-off in the population.


Greater Snow Geese are the farthest-north breeding waterfowl in North America. Summer breeding grounds range north from the Foxe Basin (the northern arm of Hudson Bay) to Elsmere Island, the farthest north of the Canadian Archipelago. Their wintering range is the mid-Atlantic Coast from New Jersey to the Carolinas. While Greater Snow Geese on most of the Delmarva come from Hudson Bay north, birds wintering along salt water come from a separate breeding population in western Greenland. Snow Geese have serrated edges to their bills, allowing for greater traction in pulling plant roots and tubers, their main diet. In the past few years, snow geese have been moving into farm fields to graze on waste grains and green cover crops such as rye or winter wheat. Watching a flock move across a field covered in sprouted rye reminds me of a party, groups come and go, aggregating and breaking up like conversation groups at a cocktail party and there is an overall background conversation buzz of honks and gabbles. Snow geese mate for life; young unattached adults meet and court their new mates on the wintering grounds. Adults who have lost mates do the same. Mixing and mingling on the wintering grounds serves to keep the population genetics mixed up—geese return to the females’ nesting areas. This may be a party in more than just metaphor.

Guest Spot

The following is an email from Alec. I post it without comment save to say that most of the people on the Titanic did not drown; they succumbed to hypothermia.

Tuesday 11:27 PM February 19, 2008

I would like to fly.

This phrase popped in my head just now, and I decided to write it down. I went swimming in the lake outside my dorm the other night. I asked Tim to borrow his soccer ball to go practice my penalty kicks, and on the way to the field the ball got away from me and fell into the lake. I had some premonition that it would, seeing as how every time I pass the lake I imagine the day I would have to go in it. So it didn’t take twenty seconds for me to take off all my shirts and jump into the freezing water to retrieve the ball. It was after that I remembered why the lake is there. The power plant (a trash incinerator) for JMU is on the top of the hill that ends in this lake. It isn’t a stretch of the imagination to say that some…unwanted things…end up in the lake. When I got out of the water I stayed squatting for a few minutes to drip dry and stay out of the harsh February wind (wind chill on Sunday was in the 20s). I put on my dry shirts, and with my soaking gym shorts and running shoes I went to the soccer field and tried my best to hit the upper 90. I suppose my inspiration of flying could come from this jaunt in a possibly radioactive lake, and I might be feeling the hints of a super power. I would not object to flying, because as I have already said:

I would like to fly.

Highland Light

Cape Cod is, in geological terms, a recessional moraine - where the glacier paused for breath on its retreat north 15,000 years ago. The terminal moraine - the point marking the ice’s farthest advance south, more or less parallels the Pennsylvania Turnpike.

The Cape Cod cliffs (technically a glacial scarp)form a bulwark against the pounding Atlantic. Highland Lighthouse sits atop the highest cliff on the Cape, about 130 feet above the beach. This boost gives the 50-foot tower an overall height above sea level of 180 feet, only about 20 feet shorter than Cape Hatteras Light,the tallest lighthouse in the U.S. Of course, the beach Hatteras is as flat as a board so its tower has to go it alone. Highland is the official name since 1976, locals, including the Park Rangers, still call it Cape Cod light.



Highland Lighthouse sits on the seventh fairway of the Highland Links Golf Course. Locals joke that all they need is the windmill from Eastham to make Highland Links the world’s only full-sized miniature golf course. Windows in the tower, including those up in the lamp room, have been struck and broken by errant golf balls. I wonder how many penalty strokes are invoked for hitting a lighthouse. Talk about hitting the broad side of a barn. Maybe the embarrassment is enough.

Highland light stands on the Cape Cod National Seashore and is jointly operated by the National Park Service and the Friends of Highland Light. The Friends run the light 24/7 as a “private aid to navigation”. Mariners use the light for a day mark, as a GPS reference point, and to tell them when they are near the offshore shoals, reputed to be the most dangerous on the Cape and which have claimed many a vessel over the years. The light is open to the public and manned by volunteer guides who sit up in the lamp room. To get there, you have to negotiate a cast iron winding stairway bolted to the brick walls. I felt like Alice through the Rabbit Hole as the steps became progressively narrower and steeper. There were no fat lighthouse keepers ever on duty at Cape Cod Lighthouse. I overheard one visitor (of a certain age) comment that climbing the stairs was like “re-enacting the birth process.” When you pop out at the top, the view is worth the climb - impressive vistas over the Atlantic and the moorland behind the lighthouse and helpful signs point out landmarks and landfalls (Portugal, due east 2500 miles; Nova Scotia, due north 700 miles).

Highland Lighthouse is one of the oldest in the U.S., dating from 1797, authorized by George Washington himself and is the first lighthouse using a revolving light. The light was originally fueled by lard, then whale oil, then kerosene, and now runs on electricity. The original lighthouse had its feet cut out from under it by constant wave erosion and toppled over the cliff in 1853, to be replaced a year later. The cliff continued to be eaten away by the waves until, in 1996, with only 50 feet to spare, the lighthouse was moved part and parcel 100 yards inland on the same day as Nauset Lighthouse and by the same outfit. Highland Light now sits well back from the cliff edge, waiting for the Atlantic to catch up.

You can walk from the light to the edge of the sheer cliff and gaze out over the ocean. The view is impressive; just you and the most ferocious mosquitoes on the planet. I don’t know how the golfers can stand it; they must bathe in repellent or have skins tough as rhinoceros hide. The Park Service probably sends out a daily cart to gather up the bodies of exsanguinated golfers just to keep the putting greens from getting too cluttered.

Slippers

“Long Island Sound is slipper shell soup.” said my friend as we walked the beach at Milford, Connecticut. Judging from the windrows of shells cast up by the tide; 90% of which were slipper shells, she looked to be spot-on correct.


The world is full of animals (and a few plants) busy earning a living pretending to be something else. A cheetah is a cat pretending to be a dog; a grey fox is a dog pretending to be a cat. Slipper shells are snails pretending to be oysters. They are also girls pretending to be boys, but more on that later.

The Atlantic slipper shell (Crepidula fornicata) is one of the most common shells you can find on any eastern beach in North America, with a few Eastern white slipper shells (Crepidula plana) tossed in just make things confusing. They get their name from the shelf or deck on the inside, which makes them resemble shapeless slippers that have been under the bed for years. The deck extends about a third the length of the shell and serves as an anchor and protection for the internal organs. The Atlantic slipper shell is arched with brown markings with the tip bent downward to one side at the back. It is up to an inch and a half long. The Eastern white slipper shell is white and flattened, sometimes a little convex or concave, and generally a bit smaller. Eastern white slippers seem to prefer the inside of old shells and the underside of old horseshoe crabs.

Eggs are brooded within the female’s shell until they develop into exact miniatures of the adult. Periodically, females lift their shells and push the juveniles out into the cold briny deep. Newly hatched young sink to the bottom, where they scrape algae from hard substrate until they settle down in the shallows. Like oyster larvae or spat, slipper shell babies set on anything hard; rocks, shells, horseshoe crabs, each other.

Once a juvenile sets, it attaches with its muscular foot and remains in the same place forever. It has functionally become an oyster - immobile and filter feeding on the microscopic algae and detritus suspended in the water. Oysters have had gazillions of years practicing filter feeding and have evolved an elegantly simple way of moving large volumes of water past their gills, which rake out food particles and pass them to the gut. It has been said that prior to the European invasion, the entire volume of Chesapeake Bay went through an oyster every three days or so. Slipper shells aren’t quite so efficient. Descended from grazing snails that use a tongue-like organ called a radula to rasp algae off rocks, they have come up with a whole new way of getting food. Mucus is secreted from specialized organs located in the mantle and just in front of the gills; the gills sweep in plankton and other particles that stick to the mucus, and the creature uses its radula to lick the whole thing up and pass it to the stomach. Not a dinner guest who would cause you to break out the good china, but it works well enough to get by.

A slipper shell needs a hard surface on which to live; they live in an environment where this critical resource is scarce and scattered. When a slipper finds a hard surface to colonize, be it a rock, piling, shell, or horseshoe crab, other young slippers are attracted to it. Slippers tend to form piles, with the oldest and biggest on the bottom, the youngest and smallest on the top. Piles can be up to ten shells deep.

Slippers are sequential hermaphrodites. The oldest and biggest is the functional female, the smallest and youngest is the functional male. The animal in between are in various stages of transition from male to female. Female is the fallback gender. When a young slipper colonizes a new surface, it becomes female and releases a pheromone to prevent others from following suite. When the female on the bottom of a stack dies, the next one up becomes female and begins to produce pheromone and eggs.

Hermaphrodism occurs throughout the animal kingdom wherever you get a sedentary species with scattered resources. The familiar orange and white clown fish is just such a species. Clown fish colonize sea anemones. Anemones possess tentacles armed with stinging cells and can capture and devour prey up to and including clown fish size. Clown fish secrete a mucus which the sea anemone chemically recognizes as itself, and which protects the clown fish. Anemones are relatively scattered along the bottom in reef environments, and are the critical resource required by the clown fish. Clown fish form groups living around and defending individual anemones. The biggest and oldest clown fish is the functional female, the next biggest, the male. The rest wait their turn. If the female dies or falls to a predator, the male becomes female and the next biggest clown fish becomes the male. Everybody moves up a notch in the hierarchy. Try explaining the movie Finding Nemo in that context. When little Nemo’s mommy and siblings are eaten by the big bad barracuda, Nemo’s daddy should become Nemo’s new mommy, and little Nemo becomes the new daddy…things go weird from there.

For all that they are mucus-eating, bisexual hermaphroditic snails pretending to be oysters, slipper shells are the most common shell on any beach from Florida to Maine. They must be doing something right.

Starry Messenger

The other night, Alec called from school. He has been pretty much incommunicado this semester, so a phone call was an occasion for some concern. Turns out he was headed back to his dorm after Marching Band practice after dark, when he happened upon the school’s astronomy club. He stopped by to chat, and was shown Comet Holmes. The club members pointed out the location for naked eye viewing and gave him a look through a telescope. He was excited and his first impulse, like ET, was to phone home.

Comet Holmes was discovered in November 1892 by (you guessed it) Mr. Edwin Holmes, a British astronomer. His namesake comet orbits the Sun once every seven years at a distance of about 200 million miles (a little over twice Earth's 93-million-mile orbit). It was re-observed in 1899 and 1906 before being lost for nearly six decades. Based on a prediction from calculations, the comet was found again in 1964.

It is a local (relatively speaking) object, reaching its farthest distance from the sun somewhere between the orbits of Mars and Jupiter. Every seven years it makes the round trip, and has been doing so for who knows how long. What makes this comet remarkable; a once in a lifetime viewing as some authorities have dubbed it, is that it periodically “erupts”. Normally a magnitude 17 object, only visible with a pretty powerful scope, it blossoms to a magnitude 3 object every 100 years or so. Magnitude 3 means it becomes as bright any star and is easily visible to the naked eye. On October 20, in less than 24 hours, it brightened by a factor of nearly 400,000 and has now up to a factor of over a million times what it was before the outburst. This is a change "absolutely unprecedented in the annals of cometary astronomy." The comet is now rivaling some of the brighter stars in the sky. When it first cooked off, some observers thought they were witnessing a super nova – an exploding star. A super nova was last seen in the galactic neighborhood around the time of Keppler and Tycho Brahe.

Theories abound as to why Holmes brightened up ("elementary Watson"--sorry, I couldn't resist), but as yet, no one has come up with anything definitive or remotely plausible. For all we know, Scottie just turned on the warp drive engines. What is amazing is that Holmes made its closest approach to the sun last May and came no closer than 190 million miles to the sun. The comet is now moving away from the sun, boggieing its way back to Jupiter. Not exactly a recipe for the typical show-off Great (notice the initial caps) comet. None the less, there it is, in the constellation Perseus.

You can see Holmes' comet almost any time this fall until it fades, when that will be is anybody's guess since we don't know how it got bright to start with. Some astronomers predict it will grow to rival the full moon in size. Go outside and find the constellation Cassiopeia. That’s the one in the North-east sky that looks like the number “3” as drawn by a first grader. (Tilt you head right and it looks like an “M”, tilt left and it’s a “W”). Find the bottom star in the group and look at about 5 o’clock. You will see a bright star in the Perseus, with a somewhat brighter star about 5 o’clock from it. This star is the top of a triangle. The bottom left star of the triangle is Comet Holmes. Look at it carefully and you will notice it is fuzzy around the edges. Binoculars bring this out even better. I set up my 20x spotting scope on the back deck and even with this relatively puny optics, I was able to see a star shining through the fuzz and the hint of a denser area in the center; the nucleus itself. Way cool.

A well-known astronomer once remarked: “Comets are like cats; they both have tails and they both go where they please.” If that is the case, then Comet 17P/Holmes must be of the Manx variety. Unlike some the so-called Great Comets (Haley on most occasions in the past thousand years, or Halle-Bop from a few years ago), Holmes does not possess a tail to speak of. Most comets can be described as “dirty snowballs,” consisting mostly of ice with chunks of rock embedded in. It may be that Holmes, with its seven-year run, has had most of the ice already ablated off the nucleus and is pretty much solid rock…or not. Like cats, comets are pretty much inscrutable.

Nauset

The light at Nauset is hard by the Town of Eastham. It is more famous than other lighthouses on Cape Cod; the red and white tower is the logo for Cape Cod Potato Chips, sold in every convenience store from Connecticut to Maine.



Pat and I climbed down the wooden steps to the narrow beach where we set up chairs and the all-important umbrella. Pat took off her sandals, dipped a toe in the water, pronounced it freezing, and ensconced herself with cool drinks, and a new mystery novel in the shade of the umbrella to enjoy the beach in her own inimitable fashion. I can’t sit still on a beach and took off back up the stairs to explore the lighthouse and environs.

Cape Cod has always had a problem with its lighthouses. The coastal cliff that (technically a glacial scarp) forms a rampart against the ocean affords a free additional fifty feet or so of elevation at Eastham, but the remorseless Atlantic nibbles away at the cliff base with every wave and every storm, and the edge keeps moving ever westward and closer to the light. Every lighthouse facing the open sea is a replacement--sometimes second or third generation--of a light that went over the lip when its feet were cut out from under it.

The current Nauset lighthouse was built in 1877 as one of the “Chatham Twins”- old postcards show the keeper’s house flanked by identical fifty-foot tall white lighthouses. The right-hand tower was dismantled in 1923 and moved by barge up the coast to the cliffs, where it replaced the last of the “Three Sisters” lights. The Sisters were themselves wooden replacements for the three original brick towers, built in 1838, when the cliff stood about 800 feet further east. The last of the brick sisters slid over in 1892-what's left of the foundations are visible at extreme low tide. The “new” Nauset Lighthouse was operated by the Coast Guard until 1955, when it was sold out of service. The owner donated the light and the grounds to the National Park Service to be a part of Cape Cod National Seashore. That seashore kept moving closer to the base until, by 1996, the cliff edge was only 25 feet from the base of the tower. The light was moved 100 yards inland, waiting for the ocean to catch up with it. Nauset Lighthouse is run by the Nauset Light Preservation Society, who keep up the maintenance and do restoration, operating the light as a “private aid to navigation”. Boaters and fisherfolk use the red and white tower as a day mark and the alternating red and white aerobeacon lights can be seen up to 20 miles at sea.



The day we were there, Nauset Beach had more that its share of surfers, most on long boards, a good number sporting grey in their beards, and all but one in full wetsuits. Long boards handle better than hot dog boards on the small waves sloshing ashore. The waves were smallish but well formed and a surfer usually had the choice of left or right breaks. Long boards give a stable smooth ride and can better take bumps with rocks as well. The beach was littered with rocks from football to chair size; dumped there by the last glacier and eroding out of the cliff face when the glacier retreated (gone back, as the locals say, for more rocks). A pair of surfers were standing up on wide Hawaiian-style paddle boards, looking like gondoliers in wetsuits with their long single oar, and were catching more curls than most.



When I was fifteen or so, I happened upon a book entitled The Outermost House by Henry Beston. I still have it; pages yellowed and corners folded, the 95 cent price tag still in the corner. Beston, a burnt-out magazine editor and bon vivant built a two-room vacation shack on the dunes at Nauset Beach and found himself unable to leave one September. Beston spent a year on Nauset Beach, recording his experiences and thoughts in longhand on a kitchen table. He wrote of storms and shipwrecks, bird migrations and fishermen. His few visitors were mostly Coast Guardsmen from the local station or the lighthouse. Beston always offered them coffee, or something a bit stronger, on winter nights. I can still remember long quotes from the book, some passages, like long-ago memorized poetry stick in my mind. It would have been nice to have visited the house, which was dedicated as a "National Literary Landmark" in 1964 by the then Secretary of the Interior, but the house was demolished by a howling Northeaster (the lady in the local bookstore called it hurricane)in 1978. The foundation and the commemorative plaque are gone as well, the beach and dunes changed, the cliffs pushed back by the constant waves and the patient sea.

Private Viewing

Sometimes I feel as if I’m the only one around paying attention. I was walking around dusk in Old Town Alexandria a couple of weeks ago, when my attention was drawn by a chittering overhead. The sound came from a flock of chimney swifts wheeling around the unused smoke stack at the old Courthouse Building on Washington Street. Having raised their babies, and prior to migration for the rain forests of the upper Amazon, swifts spend the rest of the summer feeding on the wing and forming communal roosts in (guess where) chimneys. Before the European invasion of the Americas, chimney swifts roosted in standing hollow trees, but chimneys are even better and it is rare to find them in hollow trees anymore. The wheel in the sky grew as more swifts joined and the sound level intensified. I like to think they were swapping stories of where the best spots are for the tastiest bugs and about the one that got away.

Roger Tory Peterson in his Field Guide to Birds East of the Rockies, describes swifts as "a cigar with wings". Swifts are related to hummingbirds and move their wings almost as fast. Rather than the blur you see with hummers, swifts seem to flap their wings alternately; it's just an optical illusion from the rapidity of movement; your brain interprets it as alternate movements. Swifts have tiny feet; early biologist who should have known better, thought the feet were missing altogether, leading to the group name Apodidae (no feet). Their small feet and weak toes leave swifts unable to perch on a horizontal surface as do other birds. Chimney swifts prefer to find a rough vertical surface and hook their claws into some irregularity and roost like upside down bats.

The wheel reached out to half a block in size, and it seemed as if every swift in Alexandria was circling the chimney and chattering up a storm. At some point, known only to the birds, critical mass was reached and the entire mass spiraled down the chimney like smoke going backwards. It was like some sort of magic trick, which I guess that’s really what it was. From the first circling birds to empty sky, the whole show was over in less than five minutes. The truly amazing thing was that, as I stood there, agog in astonishment at being privileged to see such a spectacle, nobody else along that busy street even bothered to look up. I mumbled a thanks for the show to Whoever might be listening, and rejoined the throng, hurrying towards my destination of the evening.