Archive for February, 2013

Feb 18 2013

Making The Snow Fly

Red-tailed hawk in snow, Schenley Park (photo by Gregory Diskin)

If you have to sit outdoors in winter, you’re bound to get snowed on.

Last month during a particularly wet snowfall, Gregg Diskin found this red-tailed hawk perched in Schenley Park.  The bird was trying to stay warm and dry but it was a challenge.  His feathers were wet and his feet were getting cold.

See how he’s tucked one foot into his breast feathers?  It looks like he’s holding his coat closed.  Brrrrr!

Fortunately feathers are very good insulation.  You don’t realize how well they work until the hawk scratches his head.

Watch the snow fly!

Red-tailed hawk makes the snow fly (photo by Gregory Diskin)

(photos by Gregory Diskin)

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Feb 17 2013

Rare Pattern

Black-legged Kittiwake at Tampa Bay (photo by Dan Irizarry)

Something strange happened in the North Atlantic this fall that prompted thousands of seabirds to migrate much further south than normal.

This juvenile black-legged kittiwake is one of them, photographed by Dan Irizarry on February 6 in Manatee County, Florida.

Hatched somewhere in Canada or Greenland, this bird normally would have spent the winter offshore between Newfoundland and North Carolina.  Instead he’s foraging at Tampa Bay.

His bold black M pattern shouts out that he’s a kittiwake.

Not only is he rare, but he really stands out.

(photo by Dan Irizarry)

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Feb 16 2013

Hold Onto Your Hats

Published by under Weather & Sky

Chelyabinsk meteor trace, 15 February 2013 (photo by Nikita Plekhanov via Wikipedia)

There we were, focusing our attention on an asteroid that was going to miss Earth when Bang!  a real live meteor zipped low over Russia yesterday morning.

The meteor taught me a lot more than the asteroid.  After it lit the sky, made an explosive boom, blew out windows, and injured more than 1,000 people I learned from NASA:

  • Its light was brighter than the sun.
  • Its contrail was 300 miles long. (That’s the distance from Pittsburgh to Philadelphia).
  • Eyewitnesses said the sonic boom lagged by three minutes … just long enough for everyone to go to their windows to watch.
  • The meteor was about the size of a bus (55 feet) but it weighed 10,000 tons –> 1,400 times heavier than a bus.
  • The atmosphere really did help after all.  When the meteor exploded it was still 12-15 miles up.  At least twice as high up as a jetliner.
  • If it was only the size of a bus and 2 to 4 times higher up than a jet, why did it cause such a problem?   Well, it was traveling at 40,000 mph!

So, hold onto your hats.  It’s the stuff we aren’t worried about that gets us.

Click here for scientific analysis (video) from The Telegraph UK.

 

(photo of the Chelyabinsk meteor’s trace by Nikita Plekhanov via Wikipedia. Click on the image to see the original)

p.s.  The meteor also taught me two things about Russian culture:  (1) Russians have dashboard cameras in their cars to protect against corrupt policemen and disputed traffic accidents, and (2) They have already made a joke about it, quoted from the Houston Chronicle: “The meteorite was supposed to fall on Dec. 21, 2012 — when many believed the Mayan calendar predicted the end of the world — but was delivered late by Russia’s notoriously inefficient postal service.”

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Feb 15 2013

Bigger Is Better In Winter

Published by under Songbirds,Tenth Page

Male House Sparrow (phot by David Lofink via Wikimedia Commons)

Much as we’re unhappy with the results, the introduction of house sparrows from Europe began a grand experiment in avian adaptation.

House sparrows were introduced to both the U.S. and New Zealand in the 1850s where they immediately became isolated from their native populations.  More than 150 years later they differ based on where they live.

In addition to changes in plumage the birds are different sizes.  In locations where winters are harsh, the birds are large.  Where the climate is moderate, they are smaller.  This effect is called Bergmann’s rule and is true of birds around the world.

In 1992 William A. Buttermer studied house sparrows at a winter roost in Ann Arbor, Michigan where he found that the largest males survived the best.

Not only were the large birds able to thermoregulate better than the small ones but they had two other advantages.  The larger birds claimed the most favored roosts and they were able to fast longer.

During winter storms birds must roost and wait for the weather to improve, so they are forced to fast.  The larger birds survived fasting better than small ones.

It’s better to be bigger in winter.

(photo by David Lofink via Wikimedia Commons.  Click on the image to see the original.  Tenth Page is a “wild card” inspired by page 161 of Ornithology by Frank B. Gill.)

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Feb 14 2013

Love Birds

Happy Valentine’s Day!

We’re not the only ones who celebrate love this month. February is raptor courtship time.

Last year on Valentine’s Day the Decorah Eagles nestcam captured the bald eagles, “Mom and Dad”, vocalizing and mating.

This year the eagles have built a second nest that’s closer to the fish hatchery and not on camera!   At this point it’s unclear which nest the eagles will use, but they’ll certainly disappoint their 60,500 followers if they choose the off camera site.

Pittsburgh’s “falconuts” experienced that disappointment a year ago when Dori and Louie chose a new nest site Downtown.  Unfortunately it looks like the peregrines aren’t coming home to the Gulf Tower so we’re going to have another year of off-camera love birds.

(video of the Decorah Eagles via YouTube)

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Feb 13 2013

Pepper On The Snow

Published by under Insects, Fish, Frogs

Snow fleas near a log (photo by Marianne Atkinson)

Have you ever seen pepper on snow?  Did the pepper jump when you approached?

Last weekend Marianne Atkinson found black sprinkles on the snow near her home in Clearfield County, PA.

The “pepper” is hard to see in her first photo. Here’s a closeup.

Several snow fleas (photo by Marianne Atkinson)

 

These are snow fleas (Hypogastrura nivicola), a springtail species that earned its name because it appears on top of snow on warm winter days and, like all springtails, it jumps like a flea to avoid danger.

Springtails as a group are very interesting creatures:

  • They are very small, less than 0.24 inches long.  To see them well you have to magnify them.
  • They have a spring-loaded furcula (like a tail) that they clasp under their bodies.  When they let go the “tail” whaps the ground and propels them into the air.
  • Springtails are technically hexapods, not insects.
  • Most springtails live in leaf litter and topsoil where they eat decomposing plants and animals.
  • They are very gregarious.
  • They are highly sensitive to drought. Because they breathe through their cuticle (hard skin) they can’t afford to dry out.
  • Springtails are a sign of good soil because they are very sensitive to herbicides, pesticides and pollution. Folsomia candida are used in the lab for soil toxicology tests because they avoid — or die of — chemicals at very low levels.
  • There can be 100,000 springtails in one cubic meter of soil, making them one of the most abundant macroscopic animals on earth.

Snow fleas themselves are extra special.  They are active in winter because they have a protein in their bodies that works like anti-freeze.

Sometimes it’s the little things that are the most fascinating.

(photos by Marianne Atkinson)

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Feb 12 2013

Sounds Like A Typewriter

White-winged Crossbill, male (photo by Heather Jacoby)

This winter in addition to irruptions of evening grosbeaks and redpolls, crossbills have come to Pennsylvania.

I’ve seen white-winged crossbills before, especially in the winter of 2009, but this year they’ve eluded me.  People send news of them to PABIRDS but when I travel to their reported location they aren’t there.  True to their irruptive nature crossbills are always on the move.  Dang!

Last week I ran into Claire Staples while on my lunch break in Oakland.  We exchanged bird sightings and Claire said she’d experienced the same problem finding crossbills until quite recently when she heard them near her home in Squirrel Hill.

The clue is their sound.  Claire says they sound like typewriters, a useful tip as I actually do remember what typewriters sound like.  Shows how old I am!

So now on my walks I’m trying hard not to look for crossbills as I don’t want to jinx my chances of seeing them.  But I’m listening for the sound of typewriters.

(Click here to hear.)

(photo by Heather Jacoby)

7 responses so far

Feb 11 2013

An Icy Parfait

Published by under Weather & Sky

Sea ice in the Arctic (photo courtesy Univeersity of Washington)

Even when scientists develop an answer to why something happened, they still test the idea to make sure they’re right.

That’s what happened with the Great Arctic Cyclone of August 2012.

Last August a rare, massive cyclone formed in Siberia and swirled out over the Arctic Ocean for days.  During its transit the sea ice disappeared faster than anyone had ever seen.  (See the swirl here.)

By September Arctic sea ice was at an all time low.  Some said the cyclone caused the lowest ice extent since record-keeping began.  Did it?  Or would the ice have melted anyway due to warm temperatures?

Scientists at the University of Washington’s Applied Physics Laboratory ran two computer simulations of last summer’s Arctic weather.  One matched the actual weather.  The other included everything except the cyclone.

The result showed that yes, “the effect is huge in the immediate aftermath of the cyclone, but after about two weeks the effect gets smaller.  By September, most of the ice that melted would have melted with or without the cyclone,” said lead author Jinlun Zhang.

Why?  Because of mixing.

Back in September most thought that the wind broke up the thin ice or pushed it into a warmer part of the ocean.  Since then scientists have learned that the ocean underneath the ice is like a layered parfait.  Just below thin ice is a layer of ice-cold fresh water.  About 65 feet down is a layer of salty water warmed by the sun.  The cyclone stirred the parfait.  The ice was exposed to the warm water beneath and it melted.

The cyclone did cause the ice to melt 10 days sooner, but in the end it made less than 5% difference in the ice extent.

So yes, the sea ice melted because it was hot last year.

Click on the photo to read more about the study in Science Daily.

(photo courtesy University of Washington)

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Feb 10 2013

Count Birds Next Weekend

Published by under Books & Events

White-breasted nuthatch (photo by Marcy Cunkelman)

Fill your feeders and get ready!  The Great Backyard Bird Count kicks off this Friday February 15.

For four days — February 15 through February 18 — you can take part in this easy citizen science project from the comfort of your home.  All you need to do is count birds for at least 15 minutes, keep track of the highest number of each species you see, and record your count here.

If you don’t have feeders, you can count birds anywhere.  If you photograph birds, submit your pictures for the GBBC Photo Contest.

Count for hours or for as little as 15 minutes.  Have fun!

Read more here on how to participate in the Great Backyard Bird Count.

(photo by Marcy Cunkelman)

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Feb 09 2013

Easy To See In Snow

Horned Lark (photo by Bobby Greene)

In snow-covered fields horned larks are easy to see because their brown backs don’t completely blend into the background.

Without snow these birds match the dirt.  The only way I find them is by luck — I hear them and then search for movement in the mud.

When the blizzard finally ends on the East Coast today, it will be easy to see horned larks against all that snow.  In the meantime in Pittsburgh our snow will melt in tomorrow’s 50 degree temperatures.

Despite the challenge of muddy fields I think I’d rather have a hard time seeing horned larks.  ;)

(photo by Bobby Greene)

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