Archive for the 'Migration' Category

Dec 16 2015

Where Do The Golden Eagles Go?

Golden eagle at the Allegheny Front Hawk Watch, 1 Nov 2011 (photo by Michael Lanzone)

Golden eagle at the Allegheny Front Hawk Watch, 1 Nov 2011 (photo by Michael Lanzone)

In late autumn birders visit the Allegheny Front Hawk Watch, hoping this iconic bird will fly by.  On a good day more than 30 golden eagles migrate past the site.

After years of observation we now take for granted that golden eagles use the Allegheny Front as a migration corridor but that wasn’t always the case.

Golden eagles (Aquila chrysaetos) occur worldwide in the northern hemisphere but their stronghold in North America is in the American West.  They’re rarely seen in the East so it was a surprise when people saw so many at the Allegheny Front.

Where were they coming from?  Where were they going?

The answers remained a mystery until 2006-2007 when Dr. Todd Katzner, Dr. Trish Miller and Michael Lanzone, fore-runners of the Eastern Golden Eagle Working Group (EGEWG), fitted a few eagles with satellite transmitters.  The data showed those birds bred in Quebec and spent the winter in the mountains of West Virginia, Virginia and Kentucky.

This tantalizing information got a boost when the group upgraded their tracking equipment.  Beginning in 2008 most of the birds were fitted with GPS-GSM units that record more frequent data points and transmit over the cell network.

Here’s an EGEWG map from Katzner Lab showing movements of 14 golden eagles, Spring 2012 to Winter 2013.  These eagles were fitted with GPS-GSM units.  (Solid lines are winter/summer homes; dashed lines are migration.)

Golden eagle movements in eastern North America, satellite telemetry, Spring 2012-Winter 2013, part 2 (map courtesy of Katzner Lab)

Golden eagle movements in eastern North America, satellite telemetry, Spring 2012-Winter 2013, part 2 (map courtesy of Katzner Lab)

Thanks to many years of tracking, we now know that the golden eagles of eastern North America breed in Canada and spend the winter in the southern and central Appalachians.  This information, plus on-going research, helps protect the eagles and their habitat.

Click here to view maps at Katzner Lab and find out where the golden eagles go.


(photo by Michael Lanzone, Cellular Tracking Technologies)

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Dec 15 2015

Robins In December

Published by under Migration,Songbirds

American Robin (photo by Chuck Tague)

American Robin (photo by Chuck Tague)

The phrase “The First Robin of Spring” is misleading. We think it means that robins leave for the winter.  Not so in Pittsburgh.  We always have robins in December.

American robins (Turdus migratorius) are very versatile birds. They change their diet for the season, eating invertebrates in summer and fruit in winter.  They take advantage of invasive species, especially earthworms and bush honeysuckle.  They move quickly to places where we’ve changed the landscape, adopting our farms and suburbs.  And they’re flexible on migration.

Studies have shown that American robins migrate an average of 300-750 miles but that average doesn’t tell the whole story.  Some flocks head directly south, arriving in Florida by early December.  Others take their time, pausing when they find abundant food along the way.  Still others stay home or travel less than 60 miles from their breeding grounds especially in the last two decades as the climate warms.

Every December, huge flocks of robins feed and roost in Allegheny County.  In 2008 Scott Kinsey discovered 100,000 of them roosting in Carnegie.  The flocks stay through the month and are counted on the Christmas Bird Counts.  Then, when the fruit is gone, the ground freezes, or there’s snow cover the robins move on.

In Pittsburgh they normally don’t leave until January.


(photo by Chuck Tague)

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Nov 14 2015

Have You Seen One Yet?

Published by under Migration,Songbirds

American tree sparrow (photo from Wikimedia Commons)

American tree sparrow (photo from Wikimedia Commons)

In the past few weeks winter sparrows have arrived in western Pennsylvania.  We’ve seen dark-eyed juncos, white-throated, white-crowned, and fox sparrows … but I haven’t heard of American tree sparrows yet.

American tree sparrows (Spizella arborea) breed in Canada and Alaska and spend the winter in weedy snow-covered fields and backyards in the Lower 48 states, though not as far south as Florida.

When they do show up they can be confusing.  They resemble chipping sparrows except for a black dot in the center of their chests and a two-tone bill.  (Notice the yellow lower mandible and the dull brown upper mandible.) The two don’t mix though. Chipping sparrows are usually gone by the time the tree sparrows get here.

Watch for the arrival of this same-but-different bird.

Have you seen an American tree sparrow yet?


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

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Nov 12 2015

A Late Fall

Flock of ducks (photo by Brian Herman)

Flock of ducks (photo by Brian Herman)

It seems to me that fall is late this year.

The leaves were late to change color and stayed on the trees longer than expected, temperatures last week were 15 degrees above normal, and the ducks are late arriving from the north.  In my city neighborhood we haven’t had a really hard frost yet.

Have you noticed this, too?

A strong El Niño is warming the northern U.S. and southern Canada this fall.  Without ice forming on the northern lakes, waterfowl have no compelling reason to come south.  When do you think the big flocks will arrive?

For a good explanation of this year’s El Niño and the Winter 2015-2016 forecast, click here at The Weather Channel.


(photo by Brian Herman)

p.s. Here’s what the El Niño looks like in an image from There’s a big warm spot in the Pacific Ocean and another one off the coast of California.

Seas surface temperature anomaly, Oct 11 - Nov 7, 2015 (image from

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Nov 10 2015

The Odd Goose

Domestic goose and wild ancestor, the greylag goose (photos from Wikimedia Commons)

Domestic goose and wild ancestor, the greylag goose (photos from Wikimedia Commons)

We’ve all seen one … an all-white goose hanging out with the mallards and Canada geese.

Even if we’re unfamiliar with barnyard geese it doesn’t take long to find out the white ones are escaped domestic waterfowl that naturally prefer the places where people feed ducks.

Their scientific name is Anser anser domesticus, the same genus and species as their wild ancestor the greylag goose (above right).

Greylag geese (Anser anser) are mottled gray-brown with paler breasts and bellies, orange bills, and pink legs.  Native to Europe and Asia they were domesticated about 4,000 years ago for their meat and eggs.  In addition to food, they’re useful as Watch Geese because they’re quick to sound the alarm and chase off intruders.  How vigilant are they?  It’s said they saved Rome by warning of a night attack by the Gauls.

Selective breeding has given domestic geese bulky bodies and big butts but they aren’t always white and that causes identification problems.  Not only do some resemble their wild ancestors but geese freely hybridize.  When a barnyard goose mates with a Canada goose they produce some really odd offspring.  Click here for pictures of the many strange results.

If you find a gray-brown goose in western Pennsylvania your field guide will suggest the greater white-fronted goose but be careful before you decide that’s what you’ve found.

Greater white-fronted geese (detail from Crossley ID Guide for Eastern Birds)

Greater white-fronted geese (detail from Crossley ID Guide Eastern Birds via Wikimedia Commons)

Greater white-fronted geese (Anser albifrons) breed in the arctic tundra and winter west of the Mississippi and in Mexico.  They’re a rare bird in western Pennsylvania so check the field marks carefully.  Greater white-fronted geese have a “white front” (white forehead and base of bill), lots of black mottling on the belly, a smaller bill and are much less bulky.

Here’s the “white front” that gave them their name.  (I added the red arrow.)

Greater white-fronted goose (detail from the Crossley ID Guide Eastern Birds, arrow added to indicate white front)

Greater white-fronted goose (detail from the Crossley ID Guide Eastern Birds via Wikimedia Commons. Arrow added to indicate white front.)

Chances are the odd goose in Pittsburgh has domestic relatives but take a really good look at him.  You never know …


(photos from Wikimedia Commons. Click on these links to see the originals: wild greylag goose, domestic goose, greater white-fronted geese from the Crossley ID Guide Eastern Birds)

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Oct 30 2015

Bald Eagle Rendezvous

If you’re a fan of bald eagles, here’s a site to put on your travel plans for next month.

Every November bald eagles congregate on the Susquehanna River at Conowingo Dam just south of the Pennsylvania border in Maryland.  Eagles like the area because the fish are easy to catch after they pass through the dam’s gateway.  We like the area because there are so many bald eagles and it’s only a 4.5-hour drive from Pittsburgh.

As you can see from the video above, it’s a popular place for photography.

If you don’t mind crowds and want to see a wide selection of raptors, visit on Saturday November 14, 2015 for Conowingo’s Bald Eagle Day.

Here’s a video from last year’s event.  Yes, there are crowds but you’ll see cool birds, too.

For more information, follow Conowingo Bald Eagles on Facebook and click here for event information.


(videos from YouTube)

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Oct 27 2015

October (and November) Hummingbirds

Published by under Migration,Songbirds

Rufous hummingbird, female, Carrolton, PA, 19 Oct 2015 (photo by Bob Mulvihill)

Female rufous hummingbird, Carrolton, PA, 19 Oct 2015 (photo by Bob Mulvihill)

Do you still have red flowers in your garden?  Are your hummingbird feeders filled and hanging?  If so you might attract a rare bird.

Our ruby-throated hummingbirds (Archilochus colubris) have left for the tropics but a few hardy northwesterners visit Pennsylvania in the fall.  They’re the Selasphorus hummingbirds.

The most likely visitors are rufous hummingbirds (Selasphorus rufus) that breed in the Pacific Northwest and as far north as Alaska.  They’re used to cool temperatures and not bothered by our weather as long as they find enough to eat.  During migration they range far and wide and often visit backyard feeders.

Solo birds can show up anywhere.  Last year Hannah Floyd found one inside Phipps Conservatory during the Pittsburgh Christmas Bird Count.  Unseen when she entered Phipps through an open window, the bird spent a good part of the winter at the red powderpuff tree (Calliandra haematocephala) in the Stove Room.

Selasphorus hummingbirds are so rare in Pennsylvania that ornithologists work hard to band every one that’s found.  Usually they’re identified as rufous hummingbirds but the species is so similar to the even-rarer-in-Pennsylvania Allen’s hummingbird (Selasphorus sasin) that the bird usually has to be in hand to tell.

If you see a hummingbird in your garden at this point, it’s rare!  Call the National Aviary’s ornithologist Bob Mulvihill right away at 412-258-1148 (office) or 412-522-5729 (cell).  Or email him at He’ll stop by to capture and band it and you’ll get a chance to see it up close. He banded the female rufous pictured above in Carrolton, Pennsylvania on October 19.

To learn more about rare fall hummingbirds in western Pennsylvania, click here at the National Aviary’s website.


p.s. While you’re waiting for a rarity, watch hummingbirds spending the winter in West Texas on Cornell Lab’s West Texas Hummingbird Cam.

(photo by Bob Mulvihill)

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Oct 26 2015

Up Close With Saw-whet Owls

Northern Saw-whet Owl at Project OwlNet Banding, 21 Oct 2015 (photo by Doug Cunzolo)

Northern Saw-whet Owl at Project OwlNet Banding, 21 Oct 2015 (photo by Doug Cunzolo)

Did you know that tiny owls are passing through Pittsburgh right now?

Northern saw-whet owls are 7-8″ long, weigh little more than a robin, and have big yellow eyes.  They live in wooded habitats where they’re fierce predators of white-footed and deer mice.  Though small (and cute) they have “attitude.”

Close up of northern saw-whet owl (photo by Bob Mulvihill)

Close up of northern saw-whet owl (photo by Bob Mulvihill)

From mid October to December saw-whet owls migrate at night from their breeding grounds in southern Canada and the northern U.S. to points south.  Each one travels alone but not very fast.  Individual owls average 10km (6.2 miles) per night and tend to reuse the same route year after year.  Every four years the species irrupts in large numbers.

We know this because of Project Owlnet, a continental network of researchers investigating owl migration, founded by owl researcher David Brinker in 1994.  In 2011 Brinker analyzed 10 years of fall banding data (81,584 owls banded!) and published his findings in The Wilson Journal of Ornithology.   Click here to read the fascinating results.

Pittsburgh joined Project Owlnet in Fall 2013 thanks to ornithologist Bob Mulvihill of the National Aviary.  Each Tuesday, Thursday and Saturday night from mid October to early December — weather permitting — Bob and his volunteers set up mist nets and play the owl’s call from dusk to midnight at Sewickley Heights Borough Park.

Bob Mulvihill holds a saw-whet owl for banding (photo by June Bernard)

Bob Mulvihill holds a saw-whet owl for banding (photo by June Bernard)

Pittsburgh’s not a main migration corridor so there are nights when no owls show up but it’s exciting when they do.  Thursday October 21 was quite a success as Bob wrote on Facebook,

Our second night of owl banding produced our second owl of the season! And lots of folks on hand to be delighted by it! A few Orionid shooting stars, a continually calling Barred Owl, and a couple of coyotes howling in the distance made for another “Who knew urban ecology could be so wild!?” kind of night.

You’re welcome to attend Pittsburgh’s Project Owlnet. Dress warmly (bring a blanket!) and show up any time.  Be sure to read more here before you go!

Now’s the time to see saw-whet owls up close.


p.s. If you can’t make it out to the park you can still support the project by “adopting” a saw-whet owl on the National Aviary website.  Click here to read more.

(photo of owl in hand by Doug Cunzolo, photo of owl face by Bob Mulvihill, photo of Bob Mulvihill with owl by June Bernard)

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Oct 24 2015

Waiting For Snowbirds But Not For Snow

Published by under Migration,Songbirds

Dark-eyed Junco, January 2014 (photo by Cris Hamilton)

Dark-eyed Junco, January 2014 (photo by Cris Hamilton)

In the normal progression of fall migration, October is when northern sparrows arrive in the Pittsburgh area.

I’ve already seen my first white-throated and white-crowned sparrows, but I haven’t seen a dark-eyed junco yet.

Some people call juncoes “snowbirds” because they arrive with the first snow.  Fortunately our juncoes get here before that happens.

I’m waiting for snowbirds, but not for snow.


(photo by Cris Hamilton)

UPDATE: First junco in my yard this fall appeared on Oct 29 after the rain. Then a pause and today (Oct 31) I have 2 juncoes.

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Oct 19 2015

Male Or Female?

Published by under Migration,Songbirds

Ruby-crowned kinglet, October 2015 (photo by Steve Gosser)

Ruby-crowned kinglet, October 2015 (photo by Steve Gosser)

You can’t tell the difference between male and female ruby-crowned kinglets (Regulus calendula) unless they’re upset.  Only males have the ruby crown that gave the bird its name but they hide it unless they’re agitated.

Fortunately for us, ruby-crowned kinglets are feisty and will raise their head feathers as a challenge to each other and just about anyone else.

Watch for them migrating through western Pennsylvania this month.

Steve Gosser photographed this one at Shenango Lake, Mercer County.


(photo by Steve Gosser)

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