Archive for the 'Musings & News' Category

Dec 16 2014

Socially Isolated? Age Faster

African grey parrot (photo by Keith Allison from Wikimedia Commons)

Early this month I wrote how lobsters don’t age because they have telomerase that repairs the DNA sequences at the ends of their chromosomes (telomeres).   Most adult organisms don’t have that advantage so every time our cells divide our telomeres get shorter.  This ages our cells and ages us.

African grey parrots are highly social creatures who are often stressed when they live alone.  It turns out that loneliness affects their telomeres.

In a study published last spring in PLOS ONE, scientists at the University of Veterinary Medicine at Vienna, Austria examined blood samples from captive African grey parrots and compared the telomeres of parrots who lived alone versus those who lived with a companion parrot. (*)

Despite being the same age, solo African grey parrots had noticeably shorter telomeres than those who lived with friends.  The solo parrots aged faster than their peers.

Not only did the study illuminate the sadness of single parrots but it suggests that “telomeres may provide a biomarker for assessing exposure to social stress.”

Read more here in Science Daily.

Humans are social creatures, too.  Doctors and nurses know that isolated humans don’t heal as fast or live as long, so when you’re sick it helps to have the care of those who love you … which leads me to an update on my husband’s recovery (see this blog post for news of his accident).

Today it’s been three weeks since Rick was hit by a car in a crosswalk.  He’s making progress though there are setbacks, such as the operation to fix his broken nose.  Fortunately his friends and relatives have rallied to help him (and me).  Rick is a very social creature — more social than I am — so calls and visits from his sister and friends have raised his spirits.

For now my life is circumscribed by his needs and appointments.  I miss birding and hiking alone (I’m not as social as Rick) but I try to go outdoors every day because that’s what keeps me sane.

We are hoping for good long telomeres when this is over.  ;)

 

(photo by Keith Allison from Wikimedia Commons.  Click on the image to see the original)

(*) The parrot news release notes that in Austria it’s illegal to keep a parrot in isolation from other parrots, though some people do.

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Dec 11 2014

TBT: Ubiquitous Human Noise

Aldo Leopold at his Salk County shack, around 1940 (photo from Univ of Wisconsin Digital Archives)

Aldo Leopold at his Salk County shack, around 1940 (photo courtesy UW Digital Archives)

Throw Back Thursday (TBT) to October 2012:

Imagine listening to birds without the sounds of human activity in the background.

In 2012 ecologists from the University of Wisconsin-Madison recreated a soundscape from Aldo Leopold’s time without today’s background noise of vehicles, airplanes, boats, trains and tools.

Click here to read more and hear what it’s like to escape our ubiquitous human noise.

 

(photo of Aldo Leopold, courtesy UW Digital Archives)

 

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Dec 02 2014

Biological Immortality

Published by under Musings & News


Male and female red lobsters (illustration by Francis Hobart Herrick via Wikimedia Commons)

Did you know that there’s such a thing as biological immortality?  That the mortality rate in some species does not increase with age?

Most plants and animals experience senescence, an age-related functional deterioration that also occurs on the micro scale. Cells progressively lose their ability to divide and grow properly.

There are some notable exceptions to this rule including hydras, a species of jellyfish, planarian flatworms and lobsters.

Lobsters achieve biological immortality by expressing telomerase through most of their tissue, even as adults. Telomerase is the enzyme that repairs the DNA sequences at the ends of the chromosomes so that when a cell divides it doesn’t lose any information.  Human fetuses have telomerase but we don’t have it as adults.  Lobsters always have it so they never age.

Despite their immortality, predation or an accident can end a lobster’s life.   Accidents come to mind right now because …

On Tuesday November 25, just before 4:00pm, my husband was hit by a car while he crossed Murray Avenue in Squirrel Hill — he was in a crosswalk! and the car had a stop sign!   He has 9 broken ribs on his right side, a broken nose, bruises, a concussion and (had at first) a partially collapsed right lung. After six days in UPMC Presbyterian Hospital, at first in the ICU then in the trauma wing, he came home late yesterday for the long, painful, healing process.  We are thankful his injuries were not worse.

In an accident, it doesn’t matter if you’re biologically immortal.

 

(illustration by Francis Hobart Herrick via Wikimedia Commons. Click on the image to see the original)

p.s.  You may be thinking, “How can she blog while this is going on?”  Answer: Birds and nature are what keep me sane.

p.p.s. Thank you, Lydia, Wes, Brittny, Amanda and Erin for such excellent care while my husband was in the hospital.

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Oct 28 2014

From T-Rex To Hummingbirds

Chart of dinosaur-to-bird evolution (illustration by Steve Brusatte)

Ancient birds have a new family tree.

In a report last month in Current Biology researchers at University of Edinburgh and Swarthmore College analyzed 850 body features of 150 dinosaurs, then used statistical analysis to assemble a detailed family tree from dinosaurs to birds.

Interestingly, they found that the evolution of bird characteristics in dinosaurs was very gradual and non-linear.  Features like feathers, wings and wishbones appeared in many species over tens of millions of years so there is no “missing link” dinosaur line to the first bird.

“This process was so gradual that if you traveled back in time to the Jurassic, you’d find that the earliest birds looked indistinguishable from many other dinosaurs,” said Swarthmore statistician Stephen Wang.

And then, 150 million years ago the bird skeleton came together and bang! there was an explosion in species from the one-of-a-kind hoatzin to more than 350 species of hummingbirds.  According to Science Daily, this explosion “supports a controversial theory proposed in the 1940s that the emergence of new body shapes in groups of species could result in a surge in their evolution.”

Read more here in Science Daily about the family tree.

Most kids go through a dinosaur-loving phase.  Some of us fall in love with birds and never come out of it.  ;)

 

(diagram by Stephen L. Brusatte, University of Edinburgh. Click on the image to see the original.)

 

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Oct 13 2014

What If…?

Published by under Musings & News

Portraits: Christopher Columbus, Passenger pigeon (images from Wikimedia Commons)

This year’s remembrance of the passenger pigeon is, for me, inextricably linked to Christopher Columbus.

Last year I read a book that generated that association.  1491: New Revelations of the Americas Before Columbus describes what North America was like before and after Columbus’ arrival.

Before Columbus, the human population in the Americas was larger than Europe’s and the landscape, animals and birds were balanced by the pressure of so many people.  Europeans arrived and accidentally left behind pigs carrying human disease.  Native Americans, who had no immunity to European disease, encountered the free-range pigs and spread the plagues through human contact.

The Western Hemisphere suddenly lost 95% of its human population in only 150 years.  Remove the keystone species and you get some pretty weird results.  European settlers didn’t see the transformation so they thought what they found was normal including the endless forest, huge bison herds and billions of passenger pigeons.

So I wonder …

If Native Americans had not died off, would passenger pigeons have boomed at all?

If there hadn’t been so many passenger pigeons, would we have hunted them to extinction?

What if?

 

(Two photos from Wikimedia Commons: portrait of Christopher Columbus by Sebastiano del Piombo, 1519.  Digital painting of the extinct Passenger Pigeon Ectopistes migratorius by Tim Hough.)

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Oct 07 2014

Water Cuts Rock

Published by under Musings & News

Kiskiminetas River at Roaring Run near Apollo, PA (photo by Kate St. John)

Amazing as it seems none of the hills in the Pittsburgh Low Plateau were ever mountains.  They were all made by water cutting rock.

When dinosaurs roamed the earth, Pittsburgh was at the shore of a shallow inland sea to our west.  At the time our soil was composed of sandy beaches, mudflats and swamps. The sand became sandstone, the mud became shale, and the decayed swamp plants became coal.

No geologic events deformed our rocks.  To our east the Appalachians slammed into the edge of the plateau and pushed up the Allegheny Mountains.  To our north the retreat of the glaciers made the land rise in a bounce-back from the pressure release.  Our plateau remained essentially flat, tilting slightly to the south and west.  Indeed the rock layers in our area are horizontal.  You can see this at highway road cuts.

But Pittsburgh doesn’t look flat.

Water transformed us, cutting dendritic paths in the landscape as it drained to the inland sea (now the Gulf of Mexico). The paths became deep valleys.  When you stand in a valley you see hills.

Vegetation now hides what happened to the land. You see the hills but none of the water cuts as shown in this view of the Kiskiminetas (Kiski) River at the mouth of Roaring Run.

Take a short hike up Roaring Run and see what water can do.

Water cuts rick at Roaring Run, Armstrong County (photo by Kate St. John)

Here the creek is carving a notch in weak shale.  The valley walls are steep and narrow.  The notch is big enough to wade in.

Eventually Roaring Run may look like the Kiski with tree-covered hills.

It all comes from water cutting rock.

 

(photos by Kate St. John)

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Sep 15 2014

In Steep Decline

Published by under Musings & News

Herring Gull (photo by Shawn Collins)

Last week I learned something new.  Did you know that herring gulls are in steep decline?

On Thursday Cornell’s Lab of Ornithology published the 2014 State of the Birds Report in honor of Martha, the last living passenger pigeon who died 100 years ago this month.  The report heralds the great conservation successes of the past 100 years — bald eagles, wood ducks, Kirtland’s warbler, brown pelicans — and warns of species currently in decline that need our attention.

Especially interesting is the list of 33 common birds in steep decline.  According to the report, “These birds have lost more than half their global population. All of these species combined have lost hundreds of millions of breeding individuals over the past four decades.”  We know from the passenger pigeon’s experience that steep decline can quickly lead to extinction so these birds are the ones to help right now.

Many are those I’ve written about in the past — common nighthawks, snow buntings, rusty blackbirds, common grackles — but the herring gull was a real surprise.   How can this species be threatened when we see them everywhere at the shore and the mall?

It turns out that herring gulls nearly went extinct in the 1880’s because of market hunting but made a stunning comeback to 100,000 birds by the 1980’s, thanks in part to humans’ wasteful ways (coastal refuse dumps and fishing boat waste).  Then the tide started to turn.  78% of the herring gull population has disappeared in the last 40 years.  Who knew?

There are plenty of birds who need our help.  Click here for the full report.  We can do it!

And here’s the list of 33 Common Species in Steep Decline.  You’ll find some surprises.

 

(photo by Shawn Collins)

http://ebird.org/ebird/view/checklist?subID=S19786167#sthash.nJ6TklhP.dpuf

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Aug 27 2014

Birds *Are* Dinosaurs

Published by under Musings & News

Four-winged dinosaur, Changyuraptor yangi, discovered in China (illustration by Stephanie Abramowicz, NHM)

(illustration by Stephanie Abramowicz, NHM)

News broke in mid-July of a newly discovered dinosaur with four wings and a very long tail.  As a member of the Microraptoria clade, Changyuraptor yangi is unusual.

Microraptors had been characterized as 2.5 – 3 feet long weighing up to 2.2. pounds, but this one broke the mold.  Changyuraptor is four feet long with 30% of its length made up of foot-long feathers at the end of its tail.  The animal is “four-winged” because it has long feathers on all four limbs.  And it was heavy — probably 9 pounds — which is four to six times heavier than a peregrine falcon, more similar in weight to a male bald eagle.

Changyuraptor’s long tail showed that this non-avian dinosaur had good flight control.  If you watch a big (modern) bird coming in for a landing you’ll see it slow its air speed by pushing down its tail and holding its head high.  The July report in Nature Communications said this dino could do that too.  Unfortunately the feathers on the raptors forewings (arms) were not well preserved, so scientists can’t tell if it could take off from the ground or only glide from trees.

Though he could fly Changyuraptor yangi is non-avian in other respects.  He had teeth instead of a beak and bones in his tail.  But he was clearly a forerunner to birds.  If you ask someone who knows a lot about dinosaurs what he thinks of birds you get a very cool answer.

In a video from the Syndey Morning Herald (click on the illustration to see the video) science columnist Peter Spinks interviews two paleontologists, one in the studio and one on the phone.  He asks both of them, “Does this clinch the deal for you that dinosaurs were the precursors of birds?”

Both answer that the deal was clinched for them long ago.  And then the second paleontologist, Mikael Siversson, adds, ““Not only are birds descended from dinosaurs, but in fact birds are dinosaurs. They are highly specialized surviving dinosaurs.”

Woo hoo!

 

Read more here at Science Matters.

(illustration of Changyuraptor yangi by Stephanie Abramowicz, Natural History Museum of Los Angeles County)

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Jul 29 2014

Even Less Water Than We Thought

Colorado River water loss as seen at Lake Mead, Nevada (photo from US Bureau of Reclamation)

Rainfall in Pittsburgh is normal this year but out West they’re in their 14th year of drought with no end in sight.  This is starkly obvious at Lake Mead near Las Vegas where the water level has dropped 138 feet, leaving a “bathtub ring” of mineral deposits.

Three western states depend on Lake Mead for water and on its dam for electricity.  Since last October 4.2 million acre feet came into the lake but 7.9 million was withdrawn.  The lake has dropped 30 feet in the past five months alone.  As the water drops so does Hoover Dam’s generating capacity, putting the electric supply at risk too.

You’d think this problem could be fixed by controlling surface water consumption but it goes much deeper than that.

Back in January, I wrote about NASA’s GRACE satellite pair that measures groundwater from outer space (click here to read how it works).  Using nine years of GRACE data from the Colorado River Basin, University of California Irvine and NASA scientists made an alarming discovery.  From December 2004 to November 2013 the watershed lost 53 million acre-feet of water, an amount almost twice the size of Lake Mead.  More than 75% of that loss was from groundwater.  No one knows how much water is underground but it’s going fast.

When wells deplete groundwater, there are significant downstream consequences.  A 2012 study by Stanford Woods Institute found that overpumping can make the surface run dry.  Though surface water is carefully managed in the West, groundwater use is often poorly documented and barely managed — if at all.

Water loss at this scale affects every living thing.  Near Las Vegas the wetlands along Lake Mead are gone and so are the birds and animals that depended on them.

If the loss continues at this rate, humans may have to leave Las Vegas, too.

 

Read more about this study in Science Daily.

(photo of Lake Mead by U.S. Bureau of Reclamation)

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May 13 2014

A Last Look?

Olive-sided flycatcher (photo by Dominic Sherony via Wikimedia Commons)

On Sunday afternoon I saw an olive-sided flycatcher above the Sand Dunes Trail at Oak Openings Preserve, Swanton, Ohio.  I mention these specifics because he was only the second olive-sided flycatcher I’ve ever seen.  The first was 11 years ago at Raccoon Creek State Park on May 18, 2003.

Olive-sided flycatchers were always uncommon and now are increasingly rare.   In the past 40 years they’ve declined 3.3% per year, especially in western North America.  Where there used to be 100 individuals there are only 27 now.  They used to nest in Pennsylvania but no more.

Though he isn’t a flashy color he’s the peregrine falcon of flycatchers.  Perched high on a dead snag he scans the air for large flying insects, dives to catch them, and chases them down if they try to escape.  This bird is fast!   I watched him chase down bees or wasps, return to the perch and swallow each catch in a single gulp.  He rarely missed.  Then, just like a bird of prey, he ejected a pellet.

Olive-sided flycatchers breed at coniferous and boreal forest edges in the western U.S. and Canada and spend the winter in northwestern South America.  They happen to prefer burned or logged areas because the openings make for better flycatching.  The bird I found was in a location that had burned several years ago.

Pesticides, loss of bees and wasps, and habitat loss in North and South America have all contributed to the olive-sided flycatcher’s decline.  A reintroduction program like the one that restored the peregrine falcon can’t save this bird.   Instead we have to cooperate to preserve large tracts of his habitat.  Unfortunately, human cooperation on this scale is notoriously difficult to achieve.

This was my second look at an olive-sided flycatcher.  Will it be my last?

 

(photo by Dominic Sherony, Creative Commons license on Wikimedia Commons. Click on the image to see the original.)

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