Archive for the 'Musings & News' Category

Oct 17 2016

The Bridge Moves

Published by under Musings & News

Rainbow Bridge, Utah (photo from Wikimedia Commons)

Rainbow Bridge, Utah (photo from Wikimedia Commons)

The Rainbow Bridge in southern Utah is a bridge of solid rock carved by water during the last ice age.  At 290 feet tall it’s one of the highest natural bridges in the world and held sacred by Native Americans in the region. But it doesn’t stand still. Like all structures it moves in response to vibration.

Last year the University of Utah obtained permission to measure resonance at the Rainbow Bridge.  Their report, published in Geophysical Research Letters, found that the bridge is affected by both natural and human activity.  Wind can make it hum. Waves from man-made Lake Powell on the Colorado River, only a mile away, make it sway a little.  During two days of measurements the bridge felt three earthquakes, one of which was a man-made earthquake in Oklahoma.

The report includes this video of the Bridge’s eight modes of resonance.  The animation is exaggerated so you can see the movements.  “Mode 7” at the 0:23 mark looks positively scary!


Read about how the Rainbow Bridge moves at Resonance in Rainbow Bridge: University of Utah study listens to the natural bridge vibrate and sing.


And speaking of scary bridge movements …

Man-made bridges are engineered to move just a little in response to wind and other forces, but they mustn’t move too much or they break.  In a spectacular case of poor design the Tacoma Narrows Bridge, built to withstand 120 mph winds, collapsed on 7 Nov 1940 in a 40 mph wind only four months after it opened.  The cause was attributed to resonance, though more recently to aeroelastic flutter.  Watch the bridge collapse below. Read the whole story here.


(photo credits:
Rainbow Bridge from Wikimedia Commons, click on the image to see the original.
video of Rainbow Bridge from University of Utah
Video of Tacoma Narrows Bridge collapse by Barney Elliot, 7 Nov 1940 via Wikimedia Commons

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Sep 29 2016

Relative Weights

House sparrow and common grackle (photos by Chuck Tague)

House sparrow and common grackle (photos by Chuck Tague)

On Throw Back Thursday:

How many house sparrows equal a common grackle?  Find out in this September 2009 article …

Weight Conversions

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Sep 28 2016

Bad Flu is Not Our Fault

Flock of ducks (photo by Brian Herman)

Flock of ducks (photo by Brian Herman)

Right now it’s flu shot season, soon to be followed by flu season itself from December to March.

Wild birds have been blamed as a source of influenza but new evidence indicates they’re not the cause of bad flu.  To understand why here’s a primer on where flu comes from, how it spreads, and why flu season is in the winter.

Where does flu come from?

Other people!  It spreads best — and quickly creates new strains — where people are densely crowded.  Amazingly, the Spanish Flu Epidemic of 1918 spread quickly because of crowded camps and trenches in World War I.  A new study this month from the University of Chicago finds that “surveillance for developing new, seasonal vaccines should be focused on areas of east, south and southeast Asia where population size and community dynamics can increase transmission of endemic strains of the flu.”  Click here to read why flu does so well in that part of the world.

How does flu spreadIn the air.  We breathe it in.  Airborne transmission actually explains …

Why is flu season in the winter?

Not too long ago we were told that it’s in the winter because migratory waterfowl pass avian flu to domestic birds during fall migration.  Wrong!!

Recent studies of avian flu transmission show that it spreads in poultry factory farms (crowded conditions!) and along our poultry trade routes.  It follows our poultry, not wild birds’ migratory paths.

And the timing has nothing to do with migration.  Flu season is in the winter because the pathogen stays airborne longer in dry winter air.  It falls to the ground in summer humidity.

So why are waterfowl off the hook?

Wild birds aren’t spreading the worst strains of avian flu because they don’t have it.

After the H5 avian influenza A virus hit U.S. poultry farms in 2014-15, officials worried that avian flu would return when waterfowl migrated south again … but it didn’t.  The reason was found by researchers from St.Jude Children’s Research Hospital who “analyzed throat swabs and biological samples taken from 22,892 wild ducks and other aquatic birds collected before, during and after a 2014-15 H5 flu outbreak in poultry.”(*)  None of the birds had the highly pathogenic influenza A virus.

“Bad flu is not our fault,” say the ducks.

Read more here at: Evidence suggests migratory birds are not a reservoir for highly pathogenic flu viruses.


p.s.  Remember to get a flu shot!  However, if you’re over 65 immunologist Laura Haynes says you should get it after Halloween if you can.  Click here to read her advice on NPR.

(photo by Brian Herman)

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Sep 22 2016

Catch Them From The Sky

Coast Guard Cutter Rush escorts the suspected high seas drift net fishing vessel Da Cheng in the North Pacific Ocean on August 14, 2012. (photo credit: U.S. Coast Guard)

Coast Guard Cutter Rush escorts suspected high seas drift net fishing vessel Da Cheng in the North Pacific Ocean on August 14, 2012 (photo from U.S. Coast Guard via NOAA)

After two days of sad stories about fish populations in decline here’s some hopeful news.

With sensible catch limits and sanctuaries where fishing is prohibited, we can turn the tide on ocean species decline — but only if we can enforce the laws.  Unfortunately the ocean is a huge place with few “cops on the beat” and a lot of places for illegal, unreported, and unregulated fishermen to hide.

Until now.

Last week Oceana, SkyTruth, and Google launched the public Beta of Global Fishing Watch (GFW), a free online tool that allows anyone in the world to monitor and track the activities of the world’s largest commercial fishing vessels in near real-time.

Here’s how it works:  Every ship over a certain tonnage is required to transmit Automatic Identification System (AIS) data containing its identity, location, course and speed.  The data, received by satellites and accumulated since 2012, is used to plot each ship’s movements.  To determine which boats are fishing vessels, Global Fishing Watch developed an algorithm that identifies fishing by the characteristic patterns it makes on the map.

The map shows no-fish zones and Economic Exclusion Zones where it’s easy to see if illegal fishing is going on.  Vessels that turn off their AIS transmitters or purposely falsify their GPS data are automatically suspect.

Nations at the mercy of illegal fishing are happy to use GFW. In December 2014, when the tool was still in test mode, SkyTruth analyst Bjorn Bergman (from his desk in West Virginia!) saw a Taiwanese boat fishing illegally in Palau’s protected waters. And it turned off its AIS. The boat left Palau and headed for Indonesia.  When it returned in January Bergman remotely helped Palau authorities chase it down. Read the whole story here at the GFW blog.

So if you’re wondering how the U.S. will stop illegal fishing in 582,578 square miles of the newly expanded Papahanaumokuakea Marine National Monument (surrounding the Northwestern Hawaiian Islands) the answer is:

We’ll catch them from the sky.

For more information, watch the video and visit the Global Fishing Watch website.

(video from Global Fishing Watch on YouTube)

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Sep 20 2016

The Biggest Die First

Large swordfish on deck during long-lining operations (photo by Derke Snodgrass via NOAA Photo Library)

Large swordfish on deck during long-lining operations (photo by Derke Snodgrass from NOAA Photo Library)

It happened to land animals. Now it’s happening in the ocean.  The biggest die first.

Based on Earth’s current extinction rate of 1,000 times the normal background rate (predicted to become 10 times worse) scientists believe we’re at the start of the sixth mass extinction.

Stanford geoscientist Jonathan Payne wondered if the traits of extinct marine animals could predict the likelihood of extinction in today’s ocean organisms. For mollusks and vertebrates Payne and his colleagues compared ecological traits such as habitat preference and body size in past extinct and present threatened genera (genus: one level above species).  The results were surprising.

In past extinctions habitat preference was a good predictor that an animal would disappear.  That’s not the case now. In this era, the best predictor of future extinction is large body size.

The difference is us.  Human hunting pressure is driving ocean extinction.  Our demand for seafood is high (there are billions of us to feed) and we’ve become very efficient at capturing the largest fish.  Highly migratory predators like the Pacific bluefin tuna have declined precipitously.

We’ve seen this before.  At the end of the Ice Age, as human population expanded across the globe, the megafauna simultaneously went extinct.  It’s now known that sabretooth tigers, giant armadillos and woolly mammoths disappeared due to human hunting.

Woolly mammoth statue in the Royal BC Museum, Victoria, BC, Canada (photo from Wikimedia Commons)

Woolly mammoth statue in the Royal BC Museum, Victoria, BC, Canada (photo from Wikimedia Commons)

We humans are successful because we make tools and hunt cooperatively.  Of course we kill the largest prey first. One large animal feeds more people.

Unfortunately we don’t know when to stop.


Read more about Payne’s study here at Science Daily.

(photo of swordfish from NOAA Photo Library. photo of woolly mammoth statue in Royal BC Museum, Victoria, Canada via Wikimedia Commons. Click on the images to see the originals)

p.s. A word about the swordfish pictured above:  Swordfish are highly migratory predators whose population is in danger — or unknown — in many oceans around the world.  In 1998 the North Atlantic population dropped so low that fishing was suspended.  A 2009 international assessment of North Atlantic swordfish showed they had recovered in U.S. fishing areas, so fishing has resumed.  Note: The fishermen who lost their lives aboard the Andrea Gail in The Perfect Storm were longline fishing for swordfish.)

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Sep 07 2016

Hey, People! Work With Me

Greater honeyguide (photo by Wilferd Duckitt via Wikimedia Commons)

Greater honeyguide (photo by Wilferd Duckitt via Wikimedia Commons)

Domestic birds work for us but here’s a wild bird who chooses to work with us.

Greater honeyguides (Indicator indicator) are wild birds in Africa known for leading humans to honey.  They eat bee eggs, larvae and beeswax but often can’t get at them because the bees fight them off.  So the birds enlist our help, “Hey, humans! Work with me.”

Chattering and fluttering in front of us, honeyguides lead us to the hives where we use smoke to subdue the bees and axes to open the tree trunks where the hives are hidden.  We get the honey.  The honeyguides get the insects and wax.

This active solicitation has gone on for thousands of years.  In July we learned a new twist in the story.

Claire Spottiswoode studied greater honeyguides in Mozambique and found that the solicitation works both ways.  People have a special call that means, “Come, honeyguide! Let’s go look for honey together.” The birds arrive and lead the way.

The calls vary by region. For instance, there’s one sound in Mozambique, another in Tanzania.  Listen to the story on NPR to hear them.

“Hey honeyguide! Come work with me.”

How the birds learned our calls is still unknown.


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

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Sep 01 2016

A Tip on Confusing Fall Warblers

Female yellow warbler (photo by Chuck Tague)

Female yellow warbler (photo by Chuck Tague)

On Throw Back Thursday:

It’s warbler time again as these tiny birds migrate south through western Pennsylvania.  They’re not as much fun as they were in the spring.

In May they were dressed in their colorful best.  This month a lot of them are wearing camouflage.  Who are these confusing fall warblers?

Back in 2009 it dawned on me that I could identify immature fall warblers because I had looked hard at their parents in the spring.  Read how it works here:

Confusing Fall Warblers


(photo by Chuck Tague)

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Aug 12 2016

Shorebird Practice

A photographer and shorebirds at the Mingan Archipelago, Quebec (photo from Wikimedia Commons)

A photographer and shorebirds at the Mingan Archipelago, Quebec (photo from Wikimedia Commons)

It’s shorebird time and many of us are confused. In southwestern Pennsylvania we only see these birds on migration and a lot of them look alike.

I’m not good at shorebirds but I want to be better.  What to do? Practice!  Here are some tips I’m using this month, written down so I don’t forget.  Maybe they’ll help you, too.

Here’s a quick summary:

  1. Prepare in advance.
  2. Take your time.
  3. For some brown/gray shorebirds, 3 field marks are all you need:
    1. Size compared to other birds,
    2. Beak shape, size and color,
    3. Leg length (relative to body) and color.

Still stumped? You’ll have to read …


Prepare in advance:

  • Choose a birding location with lots of shorebirds so you can compare sizes, shapes and behavior.
  • Before you go, narrow your choices to what’s possible at that location at that time of year. Make a list. Highlight the common ones.  Bookmarks help.
  • Take field guides(*), a scope(+), a sun hat, and maybe a chair.  These birds stay put. So will you.

Methods in the field:

  • Take your time!  Study their behavior.  Quick impressions don’t work.
  • Pick one bird to identify.  Learn it well then move on.
  • Don’t focus on plumage yet unless the bird has really striking colors or patterns.  (Plumage is the least useful field mark on difficult shorebirds.)
  • Size: Compare to other shorebirds.  (ex: smaller than a killdeer?)
  • Silhouette:
    • Beak shape: Long or short? Straight or Curved up or down? Convex (bulged) or thin?  Sharp tip or blunt?
    • Legs: Long or short relative to the body?
    • Neck: Long? Short? “No-neck”?
    • Head: Big or little? Round or long?
    • Body: Chunky? Thin? Stubby? Long?
  • Color of beak and legs.  (Sometimes size, beak and legs are all you need)
  • Behavior:
    • Stands tall or always crouched?
    • In a tight flock or solo?
    • Does it stand in water? Or does it stay at the edge, hating to get its feet wet?
    • Does it peck daintily? Grab and go? Move its bill like a sewing machine needle?
    • Does it chase waves?  (field mark of a sanderling)
  • Now look at plumage (adults + juveniles this month).  Does it match your guess?
  • Can’t make up your mind? Repeat the process.


If all else fails, hope for a peregrine or merlin to stir them up. Some species are impossible until they open their wings (willets, black-bellied plovers).  And it’s always nice to see a falcon.


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

p.s. Did I miss anything?  Do you have a tip for shorebird practice?  Please post it in a comment.

Footnotes:  Here are some great guides to use at home or while sitting in the field. These books are big and heavy.
(*) For plumage and field marks: The Sibley Guide to Birds, 2nd Edition.
(*) For detailed behavior of each species (No pictures): Pete Dunne’s Essential Field Guide Companion

(+) Scope: If you have a really good camera it can out-perform a scope. Photos show the details frozen in time.

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Jul 29 2016

Urban Birds Have It All

Peregrine falcon, Dorothy, at the Cathedral of Learning, Feb 2011 (photo by Patricia Szczepanski)

Peregrine falcon, Dorothy, at the Cathedral of Learning in February 2011 (photo by Patricia Szczepanski)

Twenty-five years ago peregrine falcons moved into the City of Pittsburgh.  Since then lots of cool raptors have come here, too, including red-tailed hawks, Coopers hawks, turkey vultures and, most recently, bald eagles.

City living provides food and protection from predators but birds face new challenges by living near humans.  Jean-Nicolas Audet of McGill University wondered if these challenges put city birds at a disadvantage compared to their country cousins so he designed some tests to answer these questions:  Which group is better at problem solving? Which group is more immune to disease?  And since both traits require lots of energy, is there a trade-off such that smarter birds have lower immunity?

The Caribbean island of Barbados has both city and country habitats and an endemic species that lives in both places, the Barbados bullfinch (Loxigilla barbadensis).  Audet tested the bullfinches and the results were surprising.

“We found that not only were birds from urbanized areas better at innovative problem-solving tasks than bullfinches from rural environments, but that surprisingly urban birds also had a better immunity than rural birds,” says Jean-Nicolas Audet, a Ph.D student in the Department of Biology and first author of the study published in the journal Behavioral Ecology in 2016.

As earth’s human population grows and more habitat is converted to cities, more birds may have to choose the urban environment.  If they can adapt, it will be a smart move.  As Audet says, “Urban birds have it all.”


Read more about the 2016 study and find links here to The town bird and the country bird: problem solving and immunocompetence vary with urbanization.

(photo of Dorothy in 2011 by Patricia Szczepanski. video from McGill University on YouTube)

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Jul 26 2016

The Largest Crop in America

Published by under Musings & News,Plants

Irrigating the largest crop in America (photo from Wikimedia Commons)

Irrigating the largest crop in America (photo from Wikimedia Commons)

If you think about it, a lot of us are farmers.  We devote our small acreage to a crop that we fertilize, water and harvest.  Then we throw away the harvest or grind it up to re-fertilize the crop.  We never eat it and we don’t feed it to our animals.

Grass.  In Pennsylvania we devote 1.8 million acres to lawns.  Our next largest crop uses 1.6 million acres. (*See table below.)

The amazing dominance of the lawn is true everywhere in the continental the U.S. except in the Central West — Montana to Nevada to Kansas — where hay, corn and soybeans take up more space.  Click here and scroll down for the map.

This isn’t really news.  A 2005 study by Cristina Melisi used satellite data to show that lawns are the largest crop in America and the most irrigated by acreage.  This is no surprise in Florida and the West where lawns have built-in irrigation systems, but do we irrigate in the Northeast?  You bet!  The sprinklers are running this month.

Some homeowners break the mold by making meadows or growing vegetables but they often have to explain it to their neighbors.  The two-year-old Beacon-Bartlett meadow in Schenley Park has educational signs explaining “This is intentional.”

If I was a gardener I’d convert my tiny backyard lawn but I’m not even a participant.  I am, at best, an observer using my Newcomb’s Guide to identify what comes up.  I never water, weed or seed it. When it grows, it gets cut. It’s not growing right now.


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

(*) TEXT UPDATED July 26, 9:30pm:  The original text was wildly incorrect!  Thank you Mary Ann Pike for providing a correction with this link at USDA.  Here’s a table combining lawn and USDA statistics for Pennsylvania:

Cultivation/ Crop Acreage in PA
Lawns 1.8 million
Hay and Haylage 1.6 million
Corn for grain/silage 1.3 million
Soybeans 0.9 million
Wheat 0.1 million

This means that lawns are about 30% of Pennsylvania’s cultivated lands.

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