Old Dampier, a rough sailor, but a man of exquisite mind
—Samuel Taylor Coleridge
Everybody loves pirates, or at least the romantic notion of pirates. In reality, pirates, all the way back to Antiquity, were universally reviled as the worst sort of sea scum--to be exterminated without mercy. Julius Caesar was captured and ransomed by pirates as a young man. Years later, he returned to their lair and executed the lot. To this day Venetians celebrate the Feast of the Seven Virgins, commemorating the victory of the Cabinetmakers Guild in 1433 over sea rovers from Trieste who abducted a group of young brides and their dowries. The Cabinetmakers hunted the pirates down, killed them all, and retrieved the dowries (no mention is made of the erstwhile brides). My dad, in researching family history, found Triestini pirates (hopefully not hanging) on several branches of the Giraldi family tree. One presumes they called in sick for the Venetian job.
William Dampier always took pains to call himself a privateer. There was often a thin line between the two; privateers were hired men o’ war, with a warrant from the king or colonial governor to harass the enemy (usually the Spanish and later, the French). Pirates were out-and-out brigands, preying on any ship they happened across, regardless of nationality, including their own—that’s what got Blackbeard in trouble.
Born in 1651 and soon orphaned, Dampier received a good basic education in mathematics and literature, including Latin. With bleak prospects ashore, he shipped out as a sailor in the Royal Navy, learning navigation and gunnery. While still in his teens, he managed a plantation in Jamaica and worked as a logwood cutter in Yucatan. Logwood was used for textile dyes and made many a man wealthy; but not Dampier. He shipped out once again from Jamaica as mate on a merchant vessel and was the last to leave when the entire crew jumped ship in the Bay of Campeche, joining a privateer off to harass the Spanish and gather plunder in the bargain. Dampier was the first person to circumnavigate the world three times and was a keen observer of exotic places, people, and events. Unique among his fellows, he kept a journal of his voyages and published them upon each return to England.
I mentioned him to Pat around Christmas time, hinting for a copy of A Pirate of Exquisite Mind, a recent biography of the old scoundrel. Instead she found me a Dover reprint of his Third Voyage Around the World in 1692. This is infinitely superior to any biography; Dampier’s voice comes through, unfiltered, across 300 years. The Dover edition keeps the syntax and spelling of the original; Dampier talks about Indian canoas (canoes) and guanoes (iguanas). His matter-of-fact descriptions of breadfruit, bananas, and “avogado pears” were their first introductions to the English-speaking world. Dampier sailed the West Indies as well as the East Indies and cruised the Galapagos Islands, writing extensively about the giant tortoises and marine iguanas he encountered. He ends each description of an exotic plant or animal with a comment on its culinary qualities. “Most sweet and wholesome a meat” when describing what is today an endangered species makes me cringe a bit, but perhaps we shouldn’t judge too harshly. These fellows were living on the edge and in one chapter, Dampier describes his timely acquisition of several sea turtles for provisions, thereby quelling an incipient mutiny. Had he been unsuccessful, he writes, the starving crew would have eaten the ship’s officers, including him.
Dampier always kept his journals with him, tucking them into a hollowed-out bamboo sealed with wax, when he was ashore trekking across the isthmus of Darien or hobnobbing with the locals on Guam or the Philippines. Dampier was the first Englishman to explore and write about Australia (New Holland). He gave the English language the word “typhoon” and, having survived a West Indian hurricane, was the first to figure out that these storms are giant whirlwinds.
The narrative of his first voyage was a huge best seller and brought him to the attention of Samuel Peppys and the Royal Society. An adventure-hungry public snapped up his books as soon as they were printed and clamored for more. Dampier became something of a cottage industry—anyone having any vague association with him published books of their travels under his “authorship” or just mentioned his name (“Sailed with Dampier against the Spanish”) in the title.
Jonathan Swift, in Gulliver’s Travels, calls him “Cousin Dampier” in the first chapter and uses Dampier’s voyage to Australia as the model for the Land of the Talking Horses in Gulliver’s fourth voyage. Daniel Defoe modeled Robinson Crusoe on Alexander Selkirk, the sailing master of a ship sailing in company with one captained by Dampier. Selkirk had grave doubts about the seaworthiness of the Cinque Ports, and asked to be put ashore. He was marooned for four years until Dampier, on his next round-the-world voyage and serving as navigator under another captain, remembered to stop and pick him up. (It turns out that Selkirk was correct in his assessment; the Cinque Ports sailed off, never to be seen again.) Defoe also borrowed from Dampier’s account of a “Moskito Indian” picked up from another island where he was five years marooned. Samuel Taylor Coleridge based the nautical bits of his Rime of the Ancient Mariner, as well as the description of the albatross, on Dampier’s observations. A century after their publication, Captain James Cook used Dampier’s books as a pilot’s guide for anchorages and prevailing currents during his own historic voyages throughout the Pacific. A half-century after Cook, Charles Darwin read Dampier for information on the natural history of South America and the Galapagos Islands. Dampier’s observations of prevailing winds in the South Seas were included the British Admiralty’s “Sailing Instructions” until the 1930 edition.
Dampier was the first modern travel writer, giving first-hand accounts of his experiences and carefully pointing out any hearsay as such. Writer, traveler, navigator, hydrographer, naturalist, and buccaneer—how cool is that.
Tuesday, March 11, 2008
Sunday, March 2, 2008
Fairydiddles
It’s dark, it’s cold, and the wind is howling through the trees like a choir of banshees. I’m standing with feet slowly going numb, on the back porch of the Long Branch Nature Center in deepest darkest suburban Arlington, Virginia, waiting on the appearance of wood sprites.
Although they are real creatures, as serious about making a living as any Internet tycoon, fairydiddles or flying squirrels have contributed to enough ghost lore in North America to qualify as semi-mythical. Readily entering houses, flying squirrels get into small spaces in search of food. Attics are a favorite haunt. Stories about spinning wheels turning without human assistance may be laid at the furry feet of these wee beasties who like nothing better than an exercise wheel, no matter what the original purpose.
About a third the size of their more familiar cousins, flying squirrels come out about an hour after dusk. They are actually more common in the mid Atlantic than grey squirrels, their bigger cousins. Being small, quick, and above all, nocturnal, they are usually seen, if at all, as a pale flash in the night woods or a dark shape against a full moon. Of the fifteen or so species world-wide (mostly in Asia including the four-foot long woolly flying squirrel), we have two; the southern and northern species. Northern flying squirrels are found in the mid Atlantic in the mountains in pockets of boreal forest left over from the glacial days and stranded on mountain tops like Dolly Sods in West Virginia. Their southern kin are everywhere else.
Flying squirrels rely mostly on nuts as winter food. Since they have small mouths and can’t stuff their cheeks like chipmunks; they must gnaw a hole in the nut to be able to grasp it while they scamper and fly. They also have a unique way of dining. Grey squirrels chew an acorn to bits while eating it; you find a pile of shell fragments. Mice leave a jagged edge as they gnaw through the shell, bisecting it like you would a soft-boiled egg. Flying squirrels will chew a round hole in the nut and extract the meat. The nut shell looks like an olive minus the pimento. While they will eat peanuts (everything is attracted to peanuts from mice to grizzly bears), flying squirrels prefer hickory nuts and hazelnuts are at the top of their culinary chart. Food not eaten on the spot is cached in scatter hordes, a few nuts here a few there, in hidden locations throughout the forest canopy. In spring and summer, flying squirrels become ravenous carnivores, feeding on large insects like grasshoppers, katydids, and moth larvae and adults. They will eat bird eggs and nestlings and the young of other squirrels, including those of their own species.
Until the babies are about three weeks old, their mothers cannot tell them from other baby flying squirrels and will care for and adopt anything cute and cuddly that they happen across. Researchers at VA Tech discovered this when a family of flying squirrels moved out of their damaged tree hole nest. The mother took a baby in her mouth and sailed off to new digs and came back for the next. The researchers would add a new baby to the nest every time she left. Twenty or so babies later, they came to the conclusion that: a) flying squirrels can’t tell their own babies from others, and b) flying squirrels can’t count.
Not only are they lacking in mathematical skills, flying squirrels can’t really fly, either. Among the mammals, only bats are capable of true powered, flap-your-wings to get where you are going flight. Flying squirrels, however, are champion gliders. They possess a specialized flap of skin, the patagium, stretching from the front legs to the back legs. This flap gives them an enormous (relative to their size) area to act as an air foil. The furry tail spreads out flat for additional airfoil area. Contrary to belief, the tail is not a rudder—flying squirrels steer by swooping and banking, much like a paper airplane. When they get to the target, they use their momentum to scoot 180 degrees to the opposite side of the tree trunk in a singe movement. This disappearing act is an anti-owl maneuver--owls are the flying squirrels’ major predator but owls must learn to counter the flip-around-the-trunk move by flying past and snatching backwards with their talons as they sweep by. In some areas where the owls have figured this move out, flying squirrels numbers are kept low. In areas with less adept owls, flying squirrel populations boom.
Flying squirrels will sometimes crash-land. They have extremely long whiskers which they point forward as they glide. The whiskers act as an early warning system; if they touch a surface first, indicating an incipient crash, the squirrel is quick enough to adjust and land more or less correctly. Flying squirrels are very noisy little beasts; they chatter constantly, even in the air. These vocalizations are so high-pitched as to be inaudible to adult people, and it was once thought that they served as a form of echo location. Up stepped our friends from VA Tech once again with another experiment. They set up a maze and let flying squirrels traverse it in low light conditions. With their outsized eyes exquisitely adapted to dim light, the squirrels had no problems navigating the maze to the reward (you guessed it, peanut butter). When the lights were fully off, leaving the maze in complete darkness, the squirrels crashed into the walls with happy abandon. The conclusion--flying squirrels don’t echo locate (at least not well) although they are very chatty.
A pale flash in the dark and the scrabbling of small claws on bark announces the arrival to the bait of the first customer of the evening. As if by magic, a small face appears on top of the squirrel roosting box, grabs a peanut, and vanishes. The flying squirrel gnaws a small hole in the nut shell to carry it away. I can hear rapid munching noises from the other side of the trunk, moving higher up into the canopy. Flying squirrels need at least a foot of elevation for every two feet they soar. The squirrel climbs to the top of the old oak and launches; we follow the flight with the beams of our flashlights, watching it hit the air brakes and flip upwards for landing on a hickory down the valley. A flip of the tail and the fairydiddle is on the far side of the tree and gone to hide the peanut for future meals.
Although they are real creatures, as serious about making a living as any Internet tycoon, fairydiddles or flying squirrels have contributed to enough ghost lore in North America to qualify as semi-mythical. Readily entering houses, flying squirrels get into small spaces in search of food. Attics are a favorite haunt. Stories about spinning wheels turning without human assistance may be laid at the furry feet of these wee beasties who like nothing better than an exercise wheel, no matter what the original purpose.
About a third the size of their more familiar cousins, flying squirrels come out about an hour after dusk. They are actually more common in the mid Atlantic than grey squirrels, their bigger cousins. Being small, quick, and above all, nocturnal, they are usually seen, if at all, as a pale flash in the night woods or a dark shape against a full moon. Of the fifteen or so species world-wide (mostly in Asia including the four-foot long woolly flying squirrel), we have two; the southern and northern species. Northern flying squirrels are found in the mid Atlantic in the mountains in pockets of boreal forest left over from the glacial days and stranded on mountain tops like Dolly Sods in West Virginia. Their southern kin are everywhere else.
Flying squirrels rely mostly on nuts as winter food. Since they have small mouths and can’t stuff their cheeks like chipmunks; they must gnaw a hole in the nut to be able to grasp it while they scamper and fly. They also have a unique way of dining. Grey squirrels chew an acorn to bits while eating it; you find a pile of shell fragments. Mice leave a jagged edge as they gnaw through the shell, bisecting it like you would a soft-boiled egg. Flying squirrels will chew a round hole in the nut and extract the meat. The nut shell looks like an olive minus the pimento. While they will eat peanuts (everything is attracted to peanuts from mice to grizzly bears), flying squirrels prefer hickory nuts and hazelnuts are at the top of their culinary chart. Food not eaten on the spot is cached in scatter hordes, a few nuts here a few there, in hidden locations throughout the forest canopy. In spring and summer, flying squirrels become ravenous carnivores, feeding on large insects like grasshoppers, katydids, and moth larvae and adults. They will eat bird eggs and nestlings and the young of other squirrels, including those of their own species.
Until the babies are about three weeks old, their mothers cannot tell them from other baby flying squirrels and will care for and adopt anything cute and cuddly that they happen across. Researchers at VA Tech discovered this when a family of flying squirrels moved out of their damaged tree hole nest. The mother took a baby in her mouth and sailed off to new digs and came back for the next. The researchers would add a new baby to the nest every time she left. Twenty or so babies later, they came to the conclusion that: a) flying squirrels can’t tell their own babies from others, and b) flying squirrels can’t count.
Not only are they lacking in mathematical skills, flying squirrels can’t really fly, either. Among the mammals, only bats are capable of true powered, flap-your-wings to get where you are going flight. Flying squirrels, however, are champion gliders. They possess a specialized flap of skin, the patagium, stretching from the front legs to the back legs. This flap gives them an enormous (relative to their size) area to act as an air foil. The furry tail spreads out flat for additional airfoil area. Contrary to belief, the tail is not a rudder—flying squirrels steer by swooping and banking, much like a paper airplane. When they get to the target, they use their momentum to scoot 180 degrees to the opposite side of the tree trunk in a singe movement. This disappearing act is an anti-owl maneuver--owls are the flying squirrels’ major predator but owls must learn to counter the flip-around-the-trunk move by flying past and snatching backwards with their talons as they sweep by. In some areas where the owls have figured this move out, flying squirrels numbers are kept low. In areas with less adept owls, flying squirrel populations boom.
Flying squirrels will sometimes crash-land. They have extremely long whiskers which they point forward as they glide. The whiskers act as an early warning system; if they touch a surface first, indicating an incipient crash, the squirrel is quick enough to adjust and land more or less correctly. Flying squirrels are very noisy little beasts; they chatter constantly, even in the air. These vocalizations are so high-pitched as to be inaudible to adult people, and it was once thought that they served as a form of echo location. Up stepped our friends from VA Tech once again with another experiment. They set up a maze and let flying squirrels traverse it in low light conditions. With their outsized eyes exquisitely adapted to dim light, the squirrels had no problems navigating the maze to the reward (you guessed it, peanut butter). When the lights were fully off, leaving the maze in complete darkness, the squirrels crashed into the walls with happy abandon. The conclusion--flying squirrels don’t echo locate (at least not well) although they are very chatty.
A pale flash in the dark and the scrabbling of small claws on bark announces the arrival to the bait of the first customer of the evening. As if by magic, a small face appears on top of the squirrel roosting box, grabs a peanut, and vanishes. The flying squirrel gnaws a small hole in the nut shell to carry it away. I can hear rapid munching noises from the other side of the trunk, moving higher up into the canopy. Flying squirrels need at least a foot of elevation for every two feet they soar. The squirrel climbs to the top of the old oak and launches; we follow the flight with the beams of our flashlights, watching it hit the air brakes and flip upwards for landing on a hickory down the valley. A flip of the tail and the fairydiddle is on the far side of the tree and gone to hide the peanut for future meals.
Thursday, February 21, 2008
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.
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.
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.
Thursday, January 3, 2008
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.
Wednesday, November 21, 2007
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.
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.
Friday, November 2, 2007
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.
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.
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