Monthly Archives: October 2017

We Migrate Five Days Later Now

Golden eagle at Allegheny Front Hawk Watch, 1 Nov 2016 (photo by Steve Gosser)
Golden eagle at Allegheny Front Hawk Watch, 1 Nov 2016 (photo by Steve Gosser)

Twenty-one years ago I attended my very first hawk watch on a spectacular golden eagle migration day -- 26 October 1996 at the Allegheny Front Hawk Watch.

Nowadays when I want to see a lot of golden eagles I visit the Allegheny Front in early November because that's when the eagles fly by.  Is it my imagination or are the birds migrating later than they used to?   A new study published last month in The Auk: Ornithological Advances confirms that raptors' autumn migration has shifted later.

The study, conducted by Hawk Mountain Sanctuary, analyzed hawk count data for 16 raptor species from 1985 to 2012 at 7 hawk watch sites in eastern North America:  Hawk Mountain Sanctuary (Kempton, PA), Hawk Ridge (Duluth, MN), Holiday Beach (Ontario, Canada), Lighthouse Point (New Haven, CT), Montreal West Island (Québec, Canada), Mount Peter (Warwick, NY), and Waggoner's Gap (Landisburg, PA).

The 16 species included both long distance migrants traveling to South America such as broad-winged hawks, and short distance migrants that stay in North America such as sharp-shinned hawks and golden eagles.  Each species adjusted its peak migration, but the delays were pronounced for short distance migrants.

To parse out the reason why raptors stay north longer, the study compared climate and air temperature data in the birds' breeding areas to the timing of migration during the 28 year period.

As you can see from this NOAA map from October 2012, the climate warmed in the breeding zone in eastern North America (marked with a yellow square).  Click here to see the details on the study's map.

Land & Ocean Temperature Anomalies, 1981-2010, NOAA (image from NOAA) Yellow square shows region of the hawk migration study.
Land & Ocean Temperature Anomalies, 1981-2010, NOAA (image from NOAA) Yellow square shows region of the hawk migration study.

Because the warming climate delays the first frost, plants and insects remain abundant later in the year. This abundance ripples all the way up the food chain to raptors who postpone their fall departure.  The study found that the shift in migration matches the pace of warming climate.

Golden eagles demonstrate the trend. Between 1985 and 2012 they waited an additional 0.16 days/year before moving south.  By 2012, the delay was 4.48 days.   Extrapolating to 2017, golden eagles are leaving 5.12 days later now than they did in 1985.

Whats' more than five days after October 26?   November 1.  So I'm going to the Allegheny Front Hawk Watch in November.

Click here to read about the study and download the full report.

 

p.s. Three species have delayed autumn migration even more than golden eagles: Sharp-shinned hawks added 0.2 days/year, northern goshawks added 0.21 days/year and black vultures added 0.40/year.

(photo by Steve Gosser)

Scurrying Squirrels

Eastern gray squirrel (photo by Marcy Cunkelman)
Eastern gray squirrel (photo by Marcy Cunkelman)

As cold weather approaches squirrels in the genus Sciurus -- the tree squirrels -- are scurrying to store food for the winter.  Here are two Sciurus you'll see in Pittsburgh.

The eastern gray squirrel (Sciurus carolinensis) is fond of nuts, especially those in bird feeders.  In autumn he turns from brown to gray so he'll continue to blend in with the landscape.  He also comes in black.

Yes, black squirrels are really eastern gray squirrels. The black ones stay black all winter.

Black gray squirrel in Schenley Park (photo by Kate St. John)
A black "eastern gray squirrel" in Schenley Park (photo by Kate St. John)

 

The fox squirrel (Sciurus niger) is larger than the gray squirrel.  Though his scientific name means "black" he sports a foxy colored coat all year long, especially on his belly.

Fox squirrel with partially open black walnut (photo by Donna Foyle)
Fox squirrel with partially open black walnut (photo by Donna Foyle)

 

Barely larger than chipmunks, the red squirrels (Tamiasciurus hudsonicus) are busy too. Cute but not true Sciurus, they're Tamiasciurus.

Red Squirrel (photo by Chuck Tague)
Red Squirrel (photo by Chuck Tague)

 

NOT found in Pittsburgh I had to include this fancy squirrel, a Sciurus with big ear tufts that lives in the mountains of Arizona, New Mexico and Colorado.  Sciurus aberti, Abert's squirrel.

Abert's squirrel (photo by Tom Benson, Creative Commons license on Flickr)
Abert's squirrel (photo by Tom Benson, Creative Commons license on Flickr)

 

(photo credits: eastern gray squirrel in gray by Marcy Cunkelman, eastern gray squirrel in black by Kate St. John, red squirrel by Chuck Tague, Abert's squirrel by Tom Benson, Creative Commons license on Flickr)

Disappointing Fall Colors

American beech leaf, 17 October 2017 (photo by Kate St. John)
American beech leaf, 17 October 2017 (photo by Kate St. John)

By now fall colors ought to be at their peak in southwestern Pennsylvania but that isn't the case this year.

Above, an American beech leaf shows hints of green and yellow but is already mostly brown.  The view below at Moraine State Park on Tuesday October 17 shows a landscape that's still green or brown and leafless.  There are no beautiful reds and yellows.

Lake Arthur at Moraine State Park, 17 October 2017 (photo by Kate St. John)
Lake Arthur at Moraine State Park, 17 October 2017 (photo by Kate St. John)

Emerald ash borer killed the trees that used to contribute yellow, orange and violet.  This year September's heat and drought suppressed the maples.

We're still waiting for the oaks to change color but they will turn a muted red.

Maybe next year.

 

(photos by Kate St. John)

A New Look Coming For The Blog

Screenshot of new theme

After a decade of blogging it's time to redecorate Outside My Window.  This weekend I'll change my blog's design by switching the WordPress Theme.

Switching the "theme" is like painting the walls a new color, installing new carpet and rearranging the furniture.  All the furniture will be the same.  It's not a radical change so you might not notice when it's done.

Why am I bothering?

Screen formats have changed since I started writing in 2007.  They are many screen sizes now, from wide desktops to tablets to cellphones, but my old design doesn't scale well.  The new theme flexibly resizes for all.  After I've made the change, compare my blog on your PC and cellphone simultaneously and you'll see subtle differences.

Also I've grown tired of the same old look.  The new theme is a different shade of white and there are seven new banner photos to display at random.  Two of the photos are my own, the other five are beautiful birds.  Thanks to Dan Arndt, Peter Bell, Chad+Chris Saladin, Chuck Tague (thank you, Joan), and Marge Van Tassel for permitting me to use their photos.

The screenshot above is a preview.

By next week the blog will have a new look.

 

(screenshot of the new design theme with banner photo of Dorothy by Peter Bell)

When Birds Lost Their Teeth

 Model of Archaeopteryx on display at Geneva natural history museum (image via Wikimedia Commons)
Model of Archaeopteryx on display at Geneva natural history museum (image via Wikimedia Commons**)

Birds have no teeth but that wasn't always the case. We know that they're descended from toothy theropod dinosaurs -- in fact birds are dinosaurs -- so when did they lose their teeth?

In 2014, genome sequencing studies led by Robert W. Meredith worked to determine whether several branches of birds' ancestry lost their teeth independently (convergent evolution) or whether all birds have a common ancestor that evolved a toothless beak.

The project did full genome sequencing on 48 birds species representing nearly all modern bird orders.  They then focused their study on six genes related to tooth enamel.  All six genes became non-functional in a common bird ancestor around 116 million years ago.  That's when birds lost their teeth.

Birds eat plenty of things that require chewing so how do they do it?  Read this 2010 blog post Anatomy: Where Are Their Teeth? to find out.

 

More information on the bird genome project is here in Science magazine.

(cropped image of Archaeopteryx model on display at Geneva natural history museum via Wikimedia Commons; click on the image to see the original.  **Note that this Archaeopteryx model has accurate teeth but has other inaccurate/disputed features as described on Wikimedia Commons: "Archaeopteryx had a more round shape of its wings, the primary feathers were attached to the second finger unlike here, and these colours are now known to be wrong.")

Sea Level Fingerprints

Fingerprint image from Wikimedia Commons
Fingerprint image from Wikimedia Commons

As ice sheets melt around the world, fresh water that used to be held on land is pouring into the ocean and sea level is rising.  But it's not rising uniformly.  The transfer of mass (water) from land to sea causes changes in Earth's gravity field.  Mirroring the ripples in gravity, the water is high in some places and low in others like the ridges on a fingerprint.

The mysteries of gravity *

Gravity is a force of attraction.  It works on everything and in both directions. The Earth's mass pulls you toward it while your mass pulls Earth toward you.  The bigger the mass, the stronger the object's gravitational pull.  Greenland with an ice sheet on top has more mass than Greenland without one, so as the ice melts Greenland's gravitational pull goes down.

As Greenland's gravity wanes it doesn't hug the ocean to its shore like it used to.  The water has to go somewhere so it rises in the tropics.  The effect is tiny, measured in millimeters per year.   The pattern is called a sea level fingerprint.

The pattern revealed

Many things contribute to sea level at any given point including the Moon's gravitational pull (causing tides) and the wind (causing waves) so it took lots of data and some serious number crunching to reveal Earth's gravitational fingerprint.  The data came from the GRACE satellite project.

GRACE satellites have been circling the Earth since 2002, measuring the pull of gravity on the globe below.  (Here's how GRACE works.)  Each orbit provides a snapshot.  Years of data show the change in gravity over time.  Most gravitational changes are due to the movement of water, especially groundwater.

Using GRACE data, scientists from NASA and the University of California Irvine mapped gravitational changes affecting sea level from 2002 to 2014, shown on the map below.  Blue means low water, red is high. The calculations were verified using readings of ocean-bottom pressure from stations in the tropics.

Sea level fingerprints (patterns of variation in sea level rise) calculated from GRACE satellite observations, 2002-2014. The blue contour (1.8 millimeters per year) shows the average sea level rise if all the water added to the ocean were spread uniformly around Earth. Image credit: NASA/UCI
Sea level fingerprints (patterns of variation in sea level rise) calculated from GRACE satellite observations, 2002-2014. The blue contour (1.8 millimeters per year) shows the average sea level rise if all the water added to the ocean were spread uniformly around Earth.
Image credit: NASA/UCI

Notice that the ocean has receded the most near Greenland at the rate of -2.5 mm/year.  That's 32.5 mm or 1.28 inches in the 13 years that GRACE measured it.  As NASA explains:

The loss of mass from land ice and from changes in land water storage increased global average sea level by about 0.07 inch (1.8 millimeters) per year, with 43 percent of the increased water mass coming from Greenland, 16 percent from Antarctica and 30 percent from mountain glaciers.

Click here to read more about the study and see an animated map of sea level changes 2002-2014.

Unfortunately some of the hardest hit places will be tiny Pacific islands and Florida.

Who knew that the sea has a "fingerprint."

 

(fingerprint image from Wikimedia Commons; click on the caption link to see the original. Sea level fingerprint map from NASA/UCI joint project using GRACE satellite data)

* p.s. Note that gravity is so mysterious that I initially described it incorrectly.  Thanks to Dr. Allen Janis, I've corrected the description. See his comment below.

In November: Bald Eagles at Conowingo

Screenshot of video, bald eagles at Conowingo Dam, fall 2016 (from video by Gerry Devinney)
Screenshot of video, bald eagles at Conowingo Dam, fall 2016 (from video by Gerry Devinney)

Want to see a lot of bald eagles?

Make a trip to Conowingo Dam in Darlington, Maryland, just south of the PA border on the Susquehanna River.  There the dam's tail-waters attract hundreds of bald eagles in November.

Last year Annette and Gerry Devinney captured great footage of adult and juvenile bald eagles fishing and chasing below the dam.  Click on the screenshot above to see Gerry's video.

If you don't mind crowds, join the fun at Conowingo Bald Eagle Day on Saturday November 4, 2017.  Conowingo Bald Eagles and Support Conowingo Dam on Facebook posted this:

SAVE THE DATE: Eagles Day 2017 is here! Join us Saturday, November 4th 10:00am to 3pm at the Conowingo Dam Pavilion. This is a great opportunity to learn about breeding, nesting, and foraging of bald eagles around Conowingo Dam as well as the overall environmental impact of the dam. Exciting vendors and presentations throughout the day! If you plan on attending, please call 410-457-2427 or email takeaction@supportconowingodam.com. We hope to see you all there!

If you miss November 4, don't worry.  The eagles stay at Conowingo for many weeks.

Make a trip any time next month to see them here on the Susquehanna.  Click here for a larger version of the map below.

 

(screenshot from video by Gerry Devinney,"Gerry Raptor" on Facebook)

Peregrine At Arrivals

Peregrine at Landside Arrivals area, Pittsburgh International Airport, 9 Oct 2017 (photo by Becky Shott)
Peregrine at Landside Arrivals area, Pittsburgh International Airport, 9 Oct 2017 (photo by Becky Shott)

Sometimes a peregrine falcon shows up in the most unlikely place.  This one was hanging out at the Landside Arrivals area at Pittsburgh International Airport.

On October 10 Ed Shott left a comment on my How Old Is That Peregrine? post.

My wife [Becky Shott] is an Allegheny County Police officer at the Pittsburgh International Airport. Yesterday [Oct 9, 2017], she saw an adult Peregrine Falcon on the public arrivals area sitting on a wall between the Landside Terminal and the parking garage. Using her cell phone, she got a video and several still pictures of the bird. She was not able to get close enough to see if there were any leg bands. She also said she has seen possibly the same bird for the past six months. It has made repeated passes around the area possibly trying to grab one of the numerous pigeons that roost in the steel beams. However, she has not seen any evidence of a nest.   -- Ed Shott

When Becky sent her photos and video she wrote:

I was pretty close to this bird & could not see any bands. I have been seeing a peregrine (maybe more than one) around here for at least 6 months. Sometimes I see it chasing pigeons around the Landside terminal. Always a beautiful sight.

Indeed this is a gorgeous bird.  Here are more views of it on October 9, 2017.  And no, I don't see any bands either, even when I zoomed in.

Peregrine walking the wall at Pittsburgh airport Arrivals, 9 Oct 2017 (photo by Becky Shott)
Peregrine walking the wall at Pittsburgh airport Arrivals, 9 Oct 2017 (photo by Becky Shott)

Peregrine walking the wall at Pittsburgh airport Arrivals, 9 Oct 2017 (photo by Becky Shott)
Peregrine at Arrivals, 9 Oct 2017 (photo by Becky Shott)

Peregrine at Landside Arrivals area, Pittsburgh International Airport, 9 Oct 2017 (photo by Becky Shott)
Peregrine at Pittsburgh airport Arrivals area, 9 Oct 2017 (photo by Becky Shott)

 

Wow!  This bird doesn't seem to care that people are nearby as long as they don't disturb it.

Many times at the airport I've thought about the large number of pigeons and starlings at the parking lots and garage, especially the huge flocks in winter.  But it never occurred to me that a peregrine would show up to eat them.

Thanks to the Shotts for alerting me to this peregrine.

If you're waiting to be picked up at the airport, watch across the driveway for a peregrine falcon.  You never know what you'll see.

 

(photos and video by Becky Shott)

Upcoming Events

Staghorn sumac in early November 2016 (photo by Kate St.John)
Staghorn sumac in early November 2016 (photo by Kate St.John)

Even though we're heading for winter the calendar is filling up with lots of bird events, so many that I'll list just four: three of mine and one at the National Aviary.

Sunday October 29, 8:30-10:30a
Duck Hollow and Lower Frick Park Bird Walk

Meet me at the Duck Hollow parking lot at the end of Old Browns Hill Road. We'll see migrating waterfowl on the river and walk the beginning of the nearby Lower Nine Mile Run Trail. Bring binoculars and scopes (for river watching) if you have them.  Check my Events page for updates or cancellations.

 

Thursday November 2, 6:00pm
Biophilia at Phipps: "Finding Pittsburgh's Winter Birds"

We often think there are no birds here in winter but that's far from the case in the city. On November 2 I'll give a short presentation at Phipps' Biophilia about Pittsburgh's winter birds and where to find them. Click here for more information.

Two male Northern Cardinals in winter (photo by Steve Gosser)
Two male Northern Cardinals in winter (photo by Steve Gosser)

 

Saturday-Sunday November 4-5, 10a - 5p, National Aviary Event
Opening Soirée, Friday November 3
Wings and Wildlife Art Show at the National Aviary.

The Wings & Wildlife Art Show is the National Aviary's annual juried show highlighting wildlife artists from across the region. Artists will be exhibiting and selling their art throughout the National Aviary during the first weekend of November. It's a great time to visit the Aviary's birds and buy a treat for yourself or gifts for the holidays. Click here for more information.

Wings and Wildlife Art Show 2017, National Aviary

 

Friday November 17, 10a
Audubon Day at Hillman Library: The Story of Peregrine Falcons at Pitt: The Dynasty Continues.

Why do peregrine falcons nest at the University of Pittsburgh's Cathedral of Learning? Where did they come from and where do they go? Come to the University of Pittsburgh's annual Audubon Day at Hillman Library where I'll tell the story of Pitt's peregrine falcons. Watch my Events page for more details including a link to Pitt's Audubon Day activities.

Peregrine falcon, Dorothy, defends her territory, May 25, 2004 (photo by Jack Rowley)
Peregrine falcon, Dorothy, defends her territory, May 25, 2004 (photo by Jack Rowley)

 

 

(photo credits: staghorn sumac by Kate St. John, northern cardinals in winter by Steve Gosser, peregrine falcon at Pitt by Jack Rowley)

Autumn Raptors

Peregrine falcon, Hillary, in autumn in Ohio (photo by Chad+Chris Saladin)
Peregrine falcon, Hillary, in autumn in Ohio, before 2011 (photo by Chad+Chris Saladin)

Today, three scenes of raptors in autumn.

Above, a peregrine falcon flies over the Rocky River.  This photo of Hillary, who nested at the Hilliard Road Bridge in Rocky River, Ohio, was taken by Chad+Chris Saladin prior to 2011.

 

A bald eagle ascends at Glade Dam Lake, Butler County, October 2017.  Photo by Steve Gosser.

Bald eagle at Glade Dam Lake, October 2017 (photo by Steve Gosser)
Bald eagle at Glade Dam Lake, October 2017 (photo by Steve Gosser)

 

A red-tailed hawk migrates south past the Allegheny Front Hawk Watch, October 2012. Photo by Steve Gosser.

Red-tailed hawk flies by the Allegheny FrontHawk Watch, October 2012 (photo by Steve Gosser)
Red-tailed hawk flies by the Allegheny Front Hawk Watch, October 2012 (photo by Steve Gosser)

 

(photos by Chad+Chris Saladin and Steve Gosser)