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Posts Tagged ‘Spring’

Among local birds, Turkey Vultures have perhaps the keenest sense of smell.

Turkey vultures migrate through our region at this time of year, bringing with them stories as old as the dinosaurs. With their bare heads and large size, it’s easier to imagine this species’ hotly debated dinosaur origins than those of a hummingbird. But one less obvious way the Turkey Vulture reminds us of how birds’ ancestors survived a mass extinction 65 million years ago is its keen sense of smell.

It’s commonly thought that birds are nearly entirely visual and auditory. After all, the portion of their brains devoted to processing the bouquet of a flower, the funk of a friend, or the reek of a rotting carcass is typically very small. But for some species, like Turkey Vultures, smell is critical. It can aid navigation, locate food, or certify kinship.

Paleontologist Darla Zelenitsky of the University of Calgary in Canada compared fossil skulls with those of modern birds (and tapped existing data) to determine how much of their circuits were aimed at smell. It seems the ancestral birds’ sense of smell greatly sharpened after the cataclysm, believed to have been an asteroid collision with Earth. More here from ScienceNOW. One can imagine buzzards circling the skies of a world of death.

Turkey Vultures and other carrion eaters play a critical role in recycling nutrients and curbing the spread of disease by acting as nature’s cleanup crew. Though their diet, defensive arsenal of projectile vomit and poo, and undertaker visages creep many people out, these birds soar gracefully on thermal vents (here gyring Fibonacci is at it again) and they can even save human lives: Turkey Vultures are sometimes used to locate natural gas leaks because they’re drawn to the smell of an additive, ethyl mercaptan.

Though Turkey Vultures fly great distances and their physiology reminds us of a remarkable global period, they’re actually pretty localized. Vultures in other parts of the world are unrelated, providing a striking example of convergent evolution — similar mutations exploit similar opportunities, and in the end you get a similar animal or plant despite genetic isolation. To find a close relative of the Turkey Vulture just head down to a local wetland. If you’re lucky you’ll spot it — the far more celebrated Blue Heron.

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Chestnut or buckeye flowers in Central Park. Photo by Hubert Steed.

 

by Erik Baard

 

I have yet to find a woman who’d swoon for buckeye tree flowers before roses, which is probably for the best – better to leave them on the tree. Besides, I can imagine a wood nymph waiting all year for these enormous floral geysers to awaken in parks throughout the city.

 

Some have compared this tree in bloom to a king in full regalia, but I recall once coming upon a young specimen and thought immediately of St. Lucia. Legend has it that she wore a wreath with candles so that she could have both hands free to carry food to Christians hiding in the darkness of the catacombs.

 

The tree gets its name from its equally impressive autumn fruit, which looks like a buck’s brown eye. They were once so prevalent across Ohio’s moist prairie bottoms that a state nickname was born.

 

But back to spring. The spectacle of these flowers is enthralling on all scales. The tree is decked out from bottom to top, which can soar to 90’ in some of the two-dozen species (including Eurasian “horse chestnut” Aesculus genus cousins). The flowers spiral upward in cones that burst with individual beauty. The flowers themselves are white at first glance, but closer viewing is rewarded with little candy drops of yellow, red, and sometimes orange. Look carefully Hubert Steed’s serene photo above of a Central Park buckeye a moment before full bloom to appreciate them.

 

You’ll notice in the photo, by the way, that a bee is busy at work. That’s a handy reminder to check our coming weekly WildWire post, or scroll down to the “Plight of the Bumble Bee” entry, to learn how you can be part of Bee Watchers 2008!

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600px-orion_nebula_-_hubble_2006_mosaic_18000.jpg

by Erik Baard

If Nature Calendar holds any value, it will be measured by how much it nurtures the feeling that your life is woven into a whole, a kinship that won’t be walled within a name. May I then call you to witness, this first weekend of spring, the birth of suns and worlds and seas?

Tonight, turn away from the busy glare of dutiful streetlamps and hurtling headlights. Climb the stairs to the roof, crawl out onto the fire escape, or stroll into the open green of a park and look to the southern sky for square-shouldered Orion. Better yet, join the star party hosted by the Amateur Astronomers Association of New York at Great Kills Gateway National Park, next Saturday, April 12.

But quietly defy millennia of tradition and see before you not a mythological hunter, but a mother.

“For many years I’ve thought the Greeks got it wrong,” said astrophysicist Mordecai-Mark Mac Low, who uses supercomputers to simulate and study stellar evolution in nebulae at the American Museum of Natural History. “If she’s giving birth to stars below her belt, Orion’s a woman.”

The Orion Nebula (a faint smudge of light reaching us across 1,600 light years of space but seen in the photo above with the Hubble Space Telescope‘s crystal clarity) had been imagined to be the center of the constellation’s sword. In fact, the Orion Complex, composed of the nebula and billowing gases and dust behind it, doesn’t resemble the clean lines of a blade so much as the hazy shape of an ultrasound, and for good reason. You’re gazing into a cosmic cloud womb.

Planetary scientist David Grinspoon also dismissed Orion’s “macho hunter dude” image and asserted, “That stellar womb has the right placental nutrients to create life. As sure as I can be about anything without direct empirical evidence, I am sure that’s where our star brethren are being born.” Grinspoon is the astrobiology curator of the Denver Museum of Nature and Science and author of Lonely Planets: A Natural Philosophy of Alien Life. He is also the interdisciplinary scientist of the European Space Agency’s ongoing Venus Express mission and a lead investigator for a radiological instrument on a coming NASA rover mission to Mars.

Our closer stellar family, from the sun to the far-flung tumble of ice worlds and comets and sister stars, may have been born in just such a place 4.65 billion years ago.

“It’s almost like a view to our own origins, and it’s happening all over the universe. Because it’s so close and we have such a good view, the Orion Nebula gives us a wonderful chance to peer outward and at the same time feel like we’re peering backward and peering inward,” Grinspoon said.

Mac Low agreed. “That’s an increasingly well supported idea,” he said.

Natural philosophers Immanuel Kant and Herbert Spencer intuited the “Nebular Hypothesis,” that there was a seamless evolution from dust to intelligence. Scientists now recognize that it’s quite a rough and uncertain ride over that arc, but the beauty and utility of that vision endures and instructs.

The Orion nebula, visible to the naked eye and lovely through binoculars or a telescope, is a scrim of hot, ionized gases blown about by the jets, shock waves, and ejected “wind” of stars birthing, churning, and dying. It twists into, and partially obscures, a trillion-mile wide molecular cloud containing hydrogen, oxygen, nitrogen, carbon, silicon, iron, and hundreds of compounds including organic substances like ammonia and methane. It’s a deep space ecology, of sorts.

Much of the material is collapsing under gravity to form new stars. The youngest and brightest of them is estimated to be a mere 10,000 years old. When it ignited, the artist from Germany’s Aurignacian culture who carved an apparent Orion star map and pregnancy chart into a sliver of mammoth tusk was already dead for over 20,000 years. Contemporaries of that star birth might have wished they could feel some of that new heat. In what would become New York City, villagers were then huddled between the foot of a receding ice sheet and rising seas.

Other juvenile stars are accreting protoplanetary discs. So far astronomers have counted what appear to be 2,300 of them in the Orion Complex, using the Spitzer Space Telescope. Heavier elements in the dust are fossils of ancestral stars that synthesized them in their increasingly strained, aging fusion generator cores before catastrophic deaths. Not only does the grittier stuff coalesce to form rocky worlds, but by shading hydrogen and oxygen from energetic ultraviolet light, it allows water to form.

According to readings from an infrared space telescope survey, the Orion cloud complex is producing water at a daily rate that would fill all of Earth’s oceans 60-times over, and already contains a million times more water than our planet. Casting our vision billions of years forward, fantasies can readily conjure a great harbor city showing as a beacon on the night side of a “lonely planet,” in a dark region of space where the Orion Nebula has long been consumed away.

How precious our moment is, a time when carbon, hydrogen, and oxygen have been formed into our brains and sensitive fingertips, to enjoy caressing striations carved into Central Park’s exposed silicate bedrock by glaciers of hydrogen and oxygen.

We are a single pulse in the body of what my murdered friend, science maverick Eugene Mallove, celebrated as The Quickening Universe.

May we at Nature Calendar never fail to remind you that this single cosmic pulse is your season to bloom.

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