Archive for January, 2014

Jan 13 2014

Melancholy Tyrant

Published by under Songbirds

Tropical kingbird (photo by barloventomagico, Creative Commons license via Flickr)

Continuing my tropical theme…

The tropical kingbird seems rare to us because his range barely touches southern Arizona and the lower Rio Grande valley, but he’s a very common bird in Central and South America and is often seen near humans because he likes what we do to the landscape — especially our wires.

I became interested in him when I learned his scientific name: Tyrannus melancholicus.  It means “melancholy tyrant.”  Why was he named this way?

Members of the Tyrannus genus are “tyrant” flycatchers because they fearlessly defend their territory, nest and young against much larger predators.  Below, a tropical kingbird attacks a zone-tailed hawk.  Our Tyrannus, the eastern kingbird, does the same to hawks in Pennsylvania.

Tropical kingbird attackes a zone-tailed hawk (photo by barloventomagico, Creative Commons license via Flickr)

Melancholicus, meaning melancholy, is not an obvious choice for such an active bird.  Mourning doves are named for their sad song so I listened to the tropical kingbird’s song in case that’s what gave him his name. Click here to hear.

It doesn’t sound sad to me, but perhaps he’s so-named because he sings this tune in the dark before dawn and stops when the sun rises.

I don’t know…  Do you?

 

(photos of tropical kingbirds in Barlovento, north-central Venezuela, by barloventomagico, Creative Commons license via Flickr) 

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Jan 12 2014

Let’s Get Tropical

Amazon kingfisher, Costa Rica (photo by Charlie Hickey)

Tired of the weather yo-yo?  Let’s get tropical.

Here’s a southern hemisphere bird that ranges from Mexico to Argentina.  She closely resembles the belted kingfisher, is virtually the same size, and has the same hunting habits.

But she’s green.  Her genus is Chloroceryle whereas the belted kingfisher’s genus is Megaceryle.

Amazon kingfishers (Chloroceryle amazona) are sexually dimorphic and follow the dimorphism of most birds — the male is more colorful than the female.  This one is female.  The males have rust color on their breasts. Click here to see a male Amazon kingfisher.

Belted kingfishers are backwards — the males are less colorful while the females have rust color on their breasts.  Click here to see a male, and here for a female.

This Amazon kingfisher was perched over water during Charlie Hickey’s fall trip to Costa Rica.  Click on his photo for a closer view of this tropical bird.

 

(photo by Charlie Hickey)

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Jan 11 2014

No Snow

Snow buntings, Crawford County, Jan 2014 (photo by Shawn Collins)

Can you believe how warm it is today?

Shawn Collins found these snow buntings in Crawford County a week ago when the snow was melting.  Two days later we were in the sub-zero polar vortex.  Now it’s 60 degrees warmer and the snow is gone.

It’s a good thing snow buntings are white, brown and black. They’re camouflaged even when there’s no snow.

(photo by Shawn Collins)

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Jan 10 2014

Like A Small Monkey

Published by under Crows, Ravens

This excellent video from Grist explains why crows are doing just fine in our changing world.

“They have a very large brain for their body size, more on par with a small monkey than a typical bird, and that allows them to quickly make associations between what they saw and what it meant,” says crow expert John Marzluff.

Don’t miss Marzluff’s information on their food choices at the 0:58 mark in the video.

Yo, crows!

(video from GristTV on YouTube)

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Jan 09 2014

Dowsing From Outer Space

Published by under Weather & Sky

GRACE satellite pair (drawing from NASA on Wikimedia Commons)

Here’s some old news to some of you… but new to me.

Launched in 2002, the twin Gravity Recovery and Climate Experiment (GRACE) satellites have collected data for 12 years and are already in a decaying orbit that will suck them down to Earth in 2015 or 2016.  During their run they’ve carefully measured Earth’s gravitational pull and contributed to our knowledge of aquifers, ice sheets, magma and earthquakes — all because of gravity.

Did you know that gravity is uneven around the world and can vary in the same location during the year?  Interestingly, water has a lot to do with it.  Gravity is determined by mass so an increase in groundwater causes a higher gravitational pull.  Since the GRACE satellites measure gravity, they find groundwater.  It’s as if they were dowsing (finding water using a forked stick).

George Casely dowsing for water on his Devon farm, 1942 (photo from Wikimedia Commons)

Here’s how it works.  Skimming like hockey pucks in their pole-to-pole orbit, the GRACE satellites maintain a 140-mile distance between each other which they measure constantly. Their microwave ranging system is so accurate it can record a 10 micrometre change in separation (1/10 the width of a human hair)!  When the lead satellite first encounters a stronger gravitational pull, gravity makes it speed ahead, increasing the distance between them.  When the second satellite encounters the same “bump” it speeds up too and their separation decreases.  When they’ve both passed the “bump” they both slow down.

Round and round since 2002 they measure the distance between themselves and report back to Earth.  NASA’s computers crunch the ebb and flow of gravity and create gravitational anomaly maps.  Click here to see a selection of them.

The maps help scientists understand changes in aquifers and improve groundwater management.  You can see the greatest anomalies in the tropics where there are dramatic wet and dry seasons.  On this map the Amazon basin is routinely blue (decreasing gravitational pull) in October at the end of the dry season and routinely red (higher gravity) in April at the end of the rainy season.  Bangladesh’s color cycle is the opposite because its wet-dry cycle occurs during the other half of the year.

Until gravity pulls them down and ends their mission the GRACE satellites travel above us, dowsing from outer space.

 

(image of the GRACE satellites and photo of George Casely dowsing on his farm from Wikimedia Commons. Click on the images to see the originals)

p.s.  Click here for more news from the GRACE satellites.

 

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Jan 08 2014

Staying Warm, Continued

Inca doves in a huddle (photo by Penny Meyer via Flickr, Creative Commons License)

In this week’s very cold weather it’s hard to stay warm but birds have a few strategies that help.

They eat a lot and they also naturally shiver to stay warm.  Shivering sounds pathetic but it actually works because the muscles generate heat.  The big pectoral (breast) muscles are the best for this.

Some birds shelter in nooks or crannies of hollow trees or on the outsides of our buildings.  Look at chimney tops and you’ll see starlings absorbing the warm exhaust.  On Monday I saw a peregrine at Pitt facing inward at a high window on the Cathedral of Learning.  The window was warmer than the surrounding air.

Other birds come indoors. On Monday afternoon Richard Nugent reported he’d found a Carolina wren sheltering in his heated garage as the temperature was heading for -12 degrees that night.  What a smart wren!  Richard put out food and water for the bird to enjoy while it waited for the weather to improve.

Huddling helps. Inca doves not only huddle sideways as shown above but they make pyramids two or three rows high.  According to Ornithology, as many as 12 Inca doves will form a pyramid, fluff their feathers and face downwind in a sheltered sunny place.  “In large pyramids, doves exposed on outside positions try for better positions in the top row and cause the whole pyramid to readjust.” This sounds like a circus act, amazing to watch.

Last night was the last of the bitter cold.  If the birds can make it through today the weather will moderate, then switch to above-normal temperatures this weekend.

Hang in there, little birds.  Help is coming soon!

 

(photo by Penny Meyer via Flickr, Creative Commons license. Today’s Tenth Page is inspired by page 158 of Ornithology by Frank B. Gill.)

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Jan 07 2014

Polar Vortex

Published by under Weather & Sky

U.S. maximum temperature map for January 6, 2014 (graphic from NOAA)

If you’ve listened to the weather forecasters you know we’re in the grips of a polar vortex.

At first that name confused me.  I know about the single massive polar vortex that spins counterclockwise in the high northern latitudes in winter, covering 620 to 1,240 square miles and reaching into the stratosphere.  Is that vortex here now?

Not exactly.  We’re experiencing a polar vortex, not the northern polar vortex, though they’re related.

In the good old days before climate change, the winter polar vortex in the northern hemisphere was generally well behaved.  It was a persistent, strong, cold, low pressure zone surrounding the polar high at roughly the same latitude around the globe.  Its strong winds kept the jet stream in line.  Nobody got too hot or too cold.

In some years — and more frequently as the Earth gets hotter — hot air from the troposphere is forced into the stratosphere and disrupts the polar vortex.  The vortex becomes disorganized and may “collapse” into smaller pieces.  Its winds weaken and the jet stream flaps like a flag in the breeze, as shown below:

Jet stream Rossby waves (graphic from Wikimedia Commons)

(a) When the polar vortex is strong, the jet stream (pink band) circles the Earth in small amplitude Rossby waves. This keeps cold air in the north and warm air in the south.
(b) When the polar vortex weakens, the jet stream begins to wobble.
(c) A major wobble brings a tongue of polar air deep into the south, spawning a (smaller break-away) polar vortex that affects our weather.  Notice how the tongue of cold air resembles yesterday’s U.S. high temperature map above.

Disruption of the winter polar vortex used to be rare, but not any more.  Last winter the polar vortex completely collapsed because of hot air from the Himalayas. The vortex broke into pieces, one of which hovered over Siberia.  The jet stream went wobbly.  Europe had a very severe winter.

This year it’s our turn.

A lot of factors created today’s weather pattern but, yes, the weakening of the polar vortex can send us a polar vortex.

Right now only the snowy owls feel at home.  ;)

 

(images from NOAA and Wikimedia Commons. Click on each image to see it’s source)

 

 

UPDATE, 10 Jan 2014:  NOAA maps show the break-up of the polar vortex.  On the left, the 500mb pressure gradient on 5 Jan 2014 shows the polar vortex in bits and pieces.  On the right, the same pressure gradient on 14-16 Nov 2013 shows a nicely contained vortex.  Click on the image to see larger images and read the accompanying article at NOAA.

Polar vorrtex 500mb pressure comparison: Jan 5, 2014 to Nov 14-16, 2013 (maps by NOAA climate.gov)

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Jan 06 2014

Help Study Snowy Owls

Snowy Owl in flight (photo by Kim Steininger)

Are you curious about the snowy owls visiting us this winter?  Would you like to know who the owls are and where they’re going?  So would a team of scientists.  They’re going to find out and you can help.

This winter’s snowy owl irruption is so huge that by December ornithologists and wildlife managers realized they had a golden opportunity to find the answers to many questions:  How old are the owls? What sex are they? Have they been exposed to toxins?  Where are they going?

Thus was born Project SNOWstorm, a collaboration of 18 scientists and 13 organizations.  The project tags snowy owls, collects data on their age, sex, and blood toxins (if any), and maps their movements via satellite.  The project also collects location-specific photos of snowy owls from anyone who wants to help.

So far Project SNOWstorm has tagged two owls, one at Buena Vista, Wisconsin, the other at Assateague, Maryland.  As soon as each owl was released his tag began transmitting at regular intervals.  Their location data is continuously collected, then mapped to make a picture of the owls’ movements.

With only two tagged owls we can already see two different approaches.  “Buena Vista” never moves far from his favorite winter territory (click here for his late December  map).  “Assateague,” on the other hand, loves to wander and has visited three states in only two weeks!  (Click here for Assateague’s map).

You can help Project SNOWstorm in two ways.  If you take pictures of snowy owls this winter, you can submit them to the project to add to their database.

Better yet, help buy more transmitters and tag more owls by making a tax deductible contribution to Project SNOWstorm via the Indiegogo website.

Click here to see a video about Project SNOWstorm and contribute via Indiegogo.

 

(photo by Kim Steininger)

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Jan 05 2014

Two Resins For Tomorrow

Published by under Musings & News,Trees

Frankincense from Yemen (photo from Wikimedia Commons)

Back in December when I wrote about amber, I learned about other tree resins important to humans.  Two of them are celebrated tomorrow on the traditional anniversary of the visit of the Magi who brought gold, frankincense and myrrh to the infant Jesus.

Frankincense, native to the Arabian peninsula and the Horn of Africa, is a hardened resin used in religious ceremonies around the world. It’s been traded for at least 5,000 years, burned as incense or steamed to release its essential oils.

The resin is produced by slashing the bark of trees in the Boswellia genus as often as two to three times a year.  Some say that Boswellia sacra produces the best.  Ironically frankincense trees are declining because agricultural pressure is clearing the land and the remaining trees can’t produce viable seeds if they’re slashed too often.

Frankincense tree, Boswellia sacra (photo from Wikimedia Commons)

 

Myrrh is the resin of thorny trees in the Commiphora genus, valued for its religious and medicinal uses.  Just like frankincense it’s produced by slashing the tree’s bark to make it ooze sap.

Myrrh (photo from Wikimedia Commons)

Commiphora myrrha is one of the species favored for myrrh and because it is native to Yemen, Somalia, Eritrea, and eastern Ethiopia Biblical scholars say that the wise man who gave that gift came from one of those countries.

Commiphora myrrha produces myrrh (image from Wikimedia Commons)

 

Tomorrow these two resins will be in the limelight, though frankincense and myrrh are used throughout the year.

 

(photos from Wikimedia Commons. Click on the images to see the originals)

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Jan 04 2014

At The Top Of The Mountain

Black rosy-finch (photo by Steve Valasek)

Here’s a bird I hope to see some day … but I’ll have to go out of my way to find it.

The black rosy-finch (Leucosticte atrata) is an alpine bird from the American West that spends all his life at high elevation.  In the summer he nests on cliffs above the treeline in the Rockies.  In the winter he moves to lower mountaintops.

Steve Valasek photographed this one at a feeder at Sandia Crest, New Mexico … at the top of the mountain.

 

(photo by Steve Valasek)

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