Tell Me How They Do This

Flock of common starlings in a thick bush, Germany (photo from Wikimedia Commons)
Flock of common starlings in a thick bush, Germany (photo from Wikimedia Commons)

In fall and winter you've probably heard large flocks of European starlings (Sturnus vulgaris) having loud conversations in thick trees or bushes.  Then suddenly the flock falls silent and takes off.

Here's a good audio example:  Listen for 53 seconds to a lot of noisy chatter. Then the birds fall silent and you hear them take off in a whoosh.  (If you don't want to wait 53 seconds, click in the middle of the audio bar after it starts rolling.)

What signal do starlings use to trigger their escape?  Is it an audio cue?  Or is it visual?

Please tell me how they do this.

 

p.s.  Did you know that female starlings sing, especially in the fall?

(Credits: Photo from Wikimedia Commons; click on the image to see the original.
Audio: Common Starling (Sturnus vulgaris), XC281737 from xeno-canto by Peter Boesman
)

Overcast

Overcast sky above a bare tree, Pittsburgh, PA, 11 Dec 2017 (photo by Kate St. John)
Overcast sky above a bare tree, Pittsburgh, PA, 11 Dec 2017 (photo by Kate St. John)

We've had a long run of overcast days that began on Sunday, December 10.

On Monday morning Pittsburgh looked gray outside my window.

Overcast sky in Pittsburgh, 11 Dec 2017, 8:15am (photo by Kate St. John)
Overcast sky in Pittsburgh, 11 Dec 2017, 8:15am (photo by Kate St. John)

 

On Tuesday it was so gloomy that a few street lights came on in Schenley Park at 11:30am.

Overcast sky in Pittsburgh, 12 Dec 2017, 11:30am (photo by Kate St. John)
Overcast sky in Pittsburgh, 12 Dec 2017, 11:30am (photo by Kate St. John)

 

On Wednesday we had a splash of sun in the morning, then overcast skies and snow.  Here's the sky above PPG Place downtown on Wednesday at 4:15pm.  The rest of the week was partly overcast, too.

The sky above PPG Place on Fourth Avenue, 13 Dec 2017, 4:15pm (photo by Kate St. John)
The sky above PPG Place on Fourth Avenue, 13 Dec 2017, 4:15pm (photo by Kate St. John)

This is not just one layer of clouds. It's often one or two low layers of broken clouds overtopped by an overcast layer.

Cloud cover is reported for aviation purposes in Weather Observations and TAF/METAR(*) at Pittsburgh International Airport (KPIT).  Here's the cloud cover for this morning and the three times photographed above:

  • 11 Dec 8:15 am ... OVC030 = Overcast at 3,000 feet
  • 12 Dec 11:35am ... BKN008 OVC039 = Broken clouds at 800 feet, Overcast at 3,900
  • 13 Dec 4:16 pm ... FEW014 OVC024 = Few clouds at 1,400 feet, Overcast at 2,400
  • 16 Dec 7:00am ...  OVC041 = Overcast at 4,100

My husband tries to see the good in everything.  He sees value in a rainy day (we need rain on a regular basis) so he wondered, "What's the value of an overcast day? What good is it?"

Ummm... perhaps... You can't get a sunburn when the clouds are this thick.

That's a poor excuse for so much gloom.

 

(photos by Kate St. John)

p.s. (*) TAF = Terminal Aerodrome Forecast. METAR = Meteorological Terminal Aviation Routine Weather Report. "Terminal" = airport terminal.

Where’s Willow?

Willow ptarmigan, East Kootenay, BC, Canada, Nov 2017 (photo by Dan Arndt)
Willow ptarmigan, East Kootenay, BC, Canada, Nov 2017 (photo by Dan Arndt)

This photo looks odd until you see a bird in it.

Willow ptarmigans (Lagopus lagopus) hide in plain sight by blending into the tundra landscape.  They're speckled brown in summer and white as snow in winter.  They virtually disappear when they close their eyes.

In late November Dan Arndt found willow ptarmigans in the snow at East Kootinay, British Columbia, Canada.

Willow ptarmigan, East Kootenay, BC, Canada, Nov 2017 (photo by Dan Arndt)
Willow ptarmigan, East Kootenay, BC, Canada, Nov 2017 (photo by Dan Arndt)

How many ptarmigans do you see?

Practice finding more ptarmigans in this 2010 article: Where's Willow?

 

(photos by Dan Arndt)

Penguin Egg May Hatch Today!

Penguins Sidney and Bette wait for their eggs to hatch at the National Aviary, 14 Dec 2017 (screenshot from African Penguin Nestcam)
Penguins Sidney and Bette wait for their eggs to hatch at the National Aviary, 14 Dec 2017 (screenshot from African Penguin Nestcam)

Sidney and Bette are "expecting." Today may be the day.

Sidney and Bette are African penguins (Spheniscus demersus), members of a critically endangered species that lives in a colony at the National Aviary in Pittsburgh.  The birds nest in burrows or under bushes so the Aviary has provided a special cubbyhole for the pair that's equipped with a nestcam so we all can watch.

Here's the action up to now, described by the National Aviary:

Penguin parents, Sidney and Bette, laid two eggs on November 7th and 11th. The first egg is expected to hatch between December 14 and 18, and the second egg is expected to hatch between December 18 and 22. If all goes well, the chicks will eventually join the National Aviary's current colony of 20 African Penguins. This is the fourth set of chicks for Sidney and Bette who have had 6 chicks together at the National Aviary (not including these two)!

It's quite a privilege to watch African penguins nesting.  There used to be 4 million of them in 1800 but now there are less than 25,000 pairs in the wild.  When these eggs hatch they'll be a significant addition to the population.

Click here or on the screenshot above to watch the African Penguin Nestcam at the National Aviary.

Will today be the day?  Only Sidney and Bette know for sure.

 

(screenshot from the African Penguin nestcam at the National Aviary)

Cooperative Hunting At The River

Peregrine falcon, Keystone, heading for prey at Heritage Park, Cleveland, Ohio (photo by Chad+Chris Saladin)
Peregrine falcon, Keystone, heading for prey at Heritage Park, Cleveland, Ohio (photo by Chad+Chris Saladin)

This is the last thing a pigeon wants to see ... and sometimes it is.

On Monday I went down the Ohio River to find birds at Rochester Riverfront Park.  It was a disappointing trip for the most part with only the usual suspects -- Canada geese, mallards and ring-billed gulls -- until I looked at the big black railroad bridge that spans the Ohio River from Monaca to Beaver.  (Click on the photo below for a larger view of the bridge.)

Railroad bridge over the Ohio River from Monaca to Beaver (photo by Kate St.John)
Railroad bridge over the Ohio River from Monaca to Beaver (photo by Kate St.John)

There was a peregrine falcon at the top of the central tower ... here.

Central tower on Monaca-Beaver railroad bridge over the Ohio River, arrow shows the peregrine perch (photo by Kate St.John)
Central tower on Monaca-Beaver railroad bridge over the Ohio River, arrow shows the peregrine perch (photo by Kate St.John)

As I watched, the peregrine flew off the tower flapping hard downriver.  She'd seen a second peregrine in the distance chasing a pigeon toward the bridge, and the pigeon was escaping.  She flew off to help her mate.

The peregrines corralled the pigeon in the air so it dove straight down to the water but one of them dove faster and hit it hard.  Dead or stunned, the prey fell in the water and started to float away.

I thought they'd lost their meal.   The peregines circled above the floating prey ... and then the female flew low over river, skimmed the water with her talons, and picked it up.

Ta dah!  She flew back to the bridge to pluck and eat.  Here's a very poor photo of her back while she was eating.

The back of a peregrine, plucking and eating prey on the Monaca-Beaver railroad bridge over the Ohio River (photo by Kate St. John)
The back of a peregrine, plucking and eating prey on the Monaca-Beaver railroad bridge over the Ohio River (photo by Kate St. John)

I'd never seen a peregrine grab prey out of the water.  It made my day.

And no, I didn't take that in-flight photo at the top of this article. That's Chad+Chris Saladin's photo of "Keystone" hunting pigeons near a bridge at Heritage Park in Cleveland, Ohio.

 

(top photo by Chad+Chris Saladin, remaining photos by Kate St.John)

p.s. The peregrine pair nests at this bridge but their young are never banded because the site is inaccessible.  Where might they be nesting?  Look at the holes in the tower below the perch.  My guess is they nest in there.  Both towers have holes with whitewash below them.

Central tower on Monaca-Beaver railroad bridge over the Ohio River, arrow shows possible nesting holes (photo by Kate St.John)
Central tower on Monaca-Beaver railroad bridge over the Ohio River, arrow shows possible nesting holes (photo by Kate St.John)

Cooper’s Hawk Family Life

  • Adult Cooper's hawk, 22 March (by BrockmeyerPhoto)

In 2016 a pair of Cooper's hawks built a nest outside Chris and Tom Brockmeyer's window in the City of Pittsburgh.

Over the spring and summer, Chris and Tom documented the nesting season in photographs.  Often the hawks were only 25 yards away.

Watch the slideshow for a unique look at these normally shy raptors.  Click on any image to see the slideshow full-screen.

 

Visit Chris and Tom's photo website for additional photos.

(photos by BrockmeyerPhoto)

Plant Or Animal?

Internal surface of the peridium of the plasmodial slime mold, Tubifera dudkae. Magnification 2000x via electronic microscope, colored with computer graphic tools (Featured photo from Wikimedia Commons)
Internal surface of the peridium of slime mold, Tubifera dudkae, magnified 2000 times (a Featured photo from Wikimedia Commons)

This beautiful photograph from Wikimedia Commons is a living organism magnified 2000 times by an electronic microscope, then colored using computer graphics.  Can you guess what it is?

The description says:  "Internal surface of the peridium of the rare myxomycete Tubifera dudkae is covered with folds resembling sea waves. Among them oval shaped reticulate spores occur."

In other words, the blue waves and brown beads are part of the same organism, a slime mold called Tubifera dudkae.  It is a rare member of the Myxomycete class.  I don't know if it occurs in North America but I do know it lives in Crimea (thanks to the photos from Wikimedia Commons) and in Tasmania, Australia (thanks to the Myxomycetes website by Sarah Lloyd, an expert in slime molds).

In the photo, the blue waves are the inner surface of the protective layer that holds the spores until they're ready to release.  This layer is called the peridium.

The brown beads with squiggly lines on them (i.e. reticulated) are the spores.

Here's what this slime mold looks like from the outside at normal size, sitting in a matchbox.

Fruiting body of the rare myxomycete Tubifera dudkae (photo from Wikimedia Commons)
Fruiting body of the rare myxomycete Tubifera dudkae (photo from Wikimedia Commons)

And here's the amazing thing:  Are slime molds plants or animals?

Neither.  They're not even fungi.  Slime molds are such weird organisms that scientists keep changing their minds about their classification.  Here's why, with thanks to Ann Jone's article The Blob:

  • In their reproductive stage, slime molds release spores.
  • When the spores settle down they become one-celled organisms similar to amoebas that move around looking for food. They don't need to swim in water to do this.
  • At some point in their life cycle, the amoeba-like individuals are drawn to each other and meld into one big cell with millions of nuclei.  Yes, there's only one cell wall.  This cell is called a plasmodium and it's slimy.
  • The plasmodium can move! In fact it oozes across the forest looking for food: bacteria, fungi, other slime molds. Some slime molds can stretch 10 feet.
  • Though they have no brain, slime molds remember where they've been and don't go back there.

Watch a slime mold move in this Deep Look video on YouTube.

Read more about slime molds in Ann Jone's Australian radio article:  The Blob, but smaller: Tasmania's slime molds.

And learn about Sarah Lloyd, a birder, gardener, and self-taught slime mold expert who lives in the wet eucalypt forest of northern Tasmania.

 

(Featured photo from Wikimedia Commons; click on the image to see the original)
p.s. I'm using the American English spelling of mold, which is also spelled mould.

The Snowies Are Coming!

Snowy Owl, Headlands Beach, Ohio, 2 Dec 2017 (photo by Anthony Bruno)
Snowy Owl, Headlands Beach, Ohio, 2 Dec 2017 (photo by Anthony Bruno)

The snowy owls are coming!

Reports from the Great Lakes to Chesapeake Bay indicate this may be a great winter for seeing snowy owls (Bubo scandiacus).  Tony Bruno traveled to Ohio last weekend and found this one at Headlands Beach.

There are clusters of snowies this month along the Great Lakes and Atlantic Coast as shown in purple on this eBird map.  The screenshot shows only December 1-8, 2017 data.  Click it to see the latest snowy owl eBird map for December 2017.

Map of snowy owl sightings in/near Pennsylvania, 1-8 Dec 2017 (screenshot from eBird)
Map of snowy owl sightings in/near Pennsylvania, 1-8 Dec 2017 (screenshot from eBird)

Is it time for a road trip?  Or will the owls come south to Pittsburgh?  Rumor has it they already have.

Read the latest snowy owl news at Project Snowstorm.  Watch PABIRDS and Ohio Bird News for location updates.

 

(photo by Anthony Bruno)

Which Glaciers Will Flood Your City?

Map of glacial contribution to sea level rise in Miami (screenshot from NASA JPL)
Map of glacial contribution to sea level rise in Miami (screenshot from NASA JPL, pink circle added to highlight Miami)

Though the ocean will never flood Pittsburgh, I'm still fascinated by the rising sea. (*)

Back in October I wrote about sea level fingerprints, the pattern of tiny elevation changes in sea level caused by uneven gravitational forces around the globe.  The highest ocean peaks are in the tropics, the deepest valleys are near melting glaciers.  As the land loses mass (ice) its gravitational pull decreases and it stops hugging the ocean to its shore.  The water has to go somewhere so it goes to the tropics.

This means that glacial melt affects sea level rise in two ways:  (1) It adds water to the ocean that used to be sequestered on land and (2) it alters the sea level fingerprint, lowering the ocean nearby and raising it far away.

If you do the complicated math, you can find out how individual melting glaciers will affect sea level at specific locations.

Last month, scientists at NASA Jet Propulsion Lab did just that when they published a paper in Science Advances and an online tool that illustrates how glaciers will affect 293 coastal cities.  Let's take a look at Miami.

Almost half the sea level rise in Miami will be caused by glaciers (47.4% of total sea level rise) and almost half of that will be Greenland's fault (20% of total sea level rise). That's why Greenland is so red in the screenshot above.

The next highest glacial contributor in Miami will be Antarctica (12% of total sea level rise).  In the screenshot below you can see that South American glaciers help, too.

Map of Antarctic and South American glacial contribution to sea level rise in Miami (screenshot from NASA JPL)
Map of Antarctic and South American glacial contribution to sea level rise in Miami (screenshot from NASA JPL)

In fact, the entire northern hemisphere is endangered by Antarctica's melting ice because it's so far away.  Ironically the safest place to be is right next to a melting glacier.  Sea level will go down at those sites.

See the maps for yourself and try the online tool at NASA JPL.  Read more about it at These are the melting glaciers that might someday drown your city, according to NASA in the Washington Post.

 

(*) Pittsburgh's Point is 711 feet above sea level. My immediate family lives 10 to 25 feet above sea level in Virginia and Florida.

(screenshots of glacial contribution to sea level rise in Miami from the online tool at NASA Jet Propulsion Lab.  On the first screenshot I added a pink circle to highlight Miami. Click on the images to use the online tool.)