Archive for the 'Bird Behavior' Category

Mar 24 2017

Pittsburgh’s Puzzling Chickadees

Black-capped chickadee (photo by Chuck Tague)

Black-capped chickadee (photo by Chuck Tague, prior to 2007)

A PABIRDS discussion about chickadees in North Park reached this surprising conclusion:  If you think you’ve seen a black-capped chickadee in Allegheny County, think again.  They’re hard to find and there are fewer every year. The reason why this is happening makes our chickadees harder to identify than your typical backyard bird.

Pittsburgh’s chickadees are puzzling because we live in the contact zone where black-capped (Poecile atricapillus) and Carolina (Poecile carolinensis) meet.  When the two meet they hybridize.  Females of both species prefer Carolina males so the birds cross and back cross until the gene pool gets really mixed up.  The hybrids aren’t as successful, though, so the species remain distinct.

Black-capped and Carolina chickadees are usually identified by range — black-cappeds in the north, Carolinas in the south — but in the contact zone they’re hard to tell apart and the hybrids have traits of both.  Some look like one species and sound like the other.  Robert Curry and his team at Villanova University study chickadees in eastern Pennsylvania’s contact zone and have found that the only reliable way to identify them is by DNA test!

Here’s a black-capped and Carolina chickadee side by side, linked from Robert Curry’s Lab website.  You can see that the black-capped is larger, more colorful, and has a relatively longer tail …

Black-capped Chickadee (left), Carolina chickadee (right). (Image linked from Robert Curry Lab Research website. Click on the image to see the original in context)

Black-capped Chickadee (left), Carolina chickadee (right). (Image linked from Robert Curry’s Lab Research website. Click on the image to see the original in context)

… but they don’t pose together in the field.  Use these tips from Project Feederwatch for identifying Pittsburgh’s chickadees.  Look and listen for more than one characteristic.  If you’re not sure, label the chickadee as Carolina/Black-capped in eBird.

So why are black-capped chickadees hard to find in Allegheny County?  Why are there fewer every year?  Because the chickadee contact zone is moving north in step with our warming climate! (more on that next week)

I used to assume that “north of the rivers” was reliable black-capped territory but not any more. In these maps from Neighborhood Nestwatch data, Bob Mulvihill plotted four years of banding black-cappeds (red), Carolinas (blue) and hybrids (green) within 50 miles of Downtown Pittsburgh.   Neighborhood Nestwatch didn’t use DNA tests; they measured the birds.

Map of black-capped, Carolina and potential hybrid chickadees banded at Neighborhood Nestwatch in southwestern Pennsylvania (map courtesy Robert Mulvihill)

Map of black-capped, Carolina and potential hybrid chickadees banded at Neighborhood Nestwatch in southwestern Pennsylvania (map courtesy Robert Mulvihill)

As you can see, the Carolinas and hybrids have (roughly) reached I-76 and jumped east of it in Monroeville.  Look at all the green dots — hybrids!  Click here for more of Bob’s chickadee maps including two zoomed in on northern Allegheny County.

Take care when you identify a chickadee in the contact zone that reaches from New Jersey to Kansas.    You can’t be lazy when identifying Pittsburgh’s puzzling chickadees.

 

(photo of black-capped chickadee at top by Chuck Tague. Black-capped and Carolina side-by-side photo is linked from Robert Curry’s Lab website.  Map of southwestern Pennsylvania Neighborhood Nestwatch chickadees: black-capped, Carolina and hybrid-sized by Robert Mulvihill, used by permission.)

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Mar 22 2017

Demonstrating Thoughts Of Love

Pigeons courting (photo by Aomorikuma via Wikimedia Commons)

Pigeons courting (photo by Aomorikuma via Wikimedia Commons)

In the spring a fuller crimson comes upon the robin’s breast
In the spring the wanton lapwing gets himself another crest
In the spring a livelier iris changes on the burnished dove
In the spring a young man’s fancy lightly turns to thoughts of love.

— from Locksley Hall by Alfred Tennyson

 

Despite this month’s cold weather birds are courting in western Pennsylvania.  In the cities, at the silos, pigeons are easiest to watch.

Learn how they demonstrate thoughts of love in this article from March 2010:

Thoughts of Love

 

p.s. The story told in Locksley Hall is different from its most famous line. Read more about the poem here.

(photo by Aomorikuma via Wikimedia Commons. Click on the image to see the original)

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Mar 17 2017

Why Is She Shouting? and Other News

Hope shouts at Terzo, 2:20pm 15 Mar 2017 (screenshot from the National Aviary falconcam at Univ of Pittsburgh)

Hope shouts at Terzo, 2:20pm 15 Mar 2017 (screenshot from the National Aviary falconcam at Univ of Pittsburgh)

Ever since the female peregrine at Pitt laid her first egg on March 15 lots of people have been watching her on camera. The first question on everyone’s mind has been, “Why is she shouting?!?”

Indeed, Hope spent a lot of time shouting at the top of her lungs on Wednesday.  Here’s just a tiny dose of her voice.

She’s always been a vocal bird but this is over the top.  People can hear her inside the Cathedral of Learning and as far away as O’Hara Street behind Soldiers and Sailors Hall.  Peter Bell @PittPeregrines said, “She’s so loud you can hear her over all the traffic!”

So why is she shouting?

I don’t know but I can tell you what was happening off camera.

Before Hope began shouting, she and her mate Terzo were communicating softly over the egg and bowing in courtship.  (Note!  This behavior is a happy thing. It is not fighting.)

After he bowed, Terzo flew up to a perch above the camera about six feet away from the egg.  Hope looked right at him and began shouting.  When he flew away she shut up and sat down on the egg.  When he came back she resumed shouting.

Peregrine shouting, also called wailing, means “I want [____] to change.”  None of us speak ‘peregrine’ so we don’t know what’s in that blank.

 

In Other News:

Hope was silent on Thursday March 16 because she was busy chasing off an unbanded female intruder.  The intruder visited the nest twice and even bowed with Terzo at 12:24pm.

In the video below you can hear Terzo and the visitor chirping for 30 seconds before Terzo jumps into the nest.  Look carefully at the female and you’ll see she resembles a bird who visited three times last year: April 8, August 2 and November 14.

 

Will this be a quiet nesting season at the Cathedral of Learning?  No.

Watch the nest on the National Aviary falconcam at the University of Pittsburgh … and be ready to press the mute button.

 

p.s. Here’s information on what happens when intruders show up: Peregrine Fidelity to Their Mates, Fighting.

p.p.s  Three eggs at the Pitt nest as of Monday morning, March 20.

(screenshot and videos from the National Aviary falconcam at Univ of Pittsburgh streamed by Wildearth.tv)

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Mar 14 2017

Nesting in a Snow Storm

Peregrine incubating in a snow storm, Harrisburg, PA, 14 Mar 2017, 6:00am (snapshot from the DEP Falcon Cam)

Peregrine incubating eggs during snow storm, Harrisburg, PA, 14 Mar 2017, 6:00am (snapshot from the DEP Falcon Cam)

One of Pennsylvania’s peregrine falcon families has a big challenge today.  They’re incubating three eggs in Harrisburg where the “Nor’easter” will bring 9 to 13 inches of snow and blustery winds until 10pm tonight.

Their nest is on a ledge of the Rachel Carson Building where four cameras provide live streams of their activity. Two snapshots taken before dawn show there was already a lot of snow at 6am.   Below, a view from the closeup camera.

Peregrine incubating in a snow storm, Harrisburg, PA, 14 Mar 2017, 6:00am (snapshot from the DEP Falcon Cam)

Peregrine incubating in a snow storm, Harrisburg, PA, 14 Mar 2017, 6:00am (snapshot from the PA Falcon Cam)

The situation looks awful to us but it’s all in a day’s work for peregrine falcons.  Here’s why:

  • Snow is a normal challenge during the nesting season.  Peregrines lay eggs in late winter so that their young will hatch when food is plentiful during spring migration. There are many stories of successful peregrine nests after blizzards in the Snow Belt. Ask folks from Cleveland, Ohio and Rochester, New York about their peregrines!
  • Feathers provide excellent insulation.  These birds are wearing down “coats” underneath their smooth body feathers.  Notice the unmelted snow on the female’s back.  This is good!
  • The brood patch (bare skin on their bellies) keeps the eggs quite warm.

During a brief respite in the snowfall, the female peregrine stood up at 6:25am.  You can see that her body has kept the nest free of snow.  Don’t worry, she was back on those eggs within 30 seconds!

The peregrines' nest has been kept warm, 14 Mar 2017, 6:25am (photo from the DEP Falcon Cam in Harriburg, PA)

The peregrines’ nest has been kept warm, 14 Mar 2017, 6:25am (photo from the PA Falcon Cam in Harriburg, PA)

Click any one of the photos above to go directly to the Live PA Falcon Cam or click here for the complete website.

Meanwhile, here in Pittsburgh we have no snow at all.

 

(snapshots from the PA Falcon Cam in Harrisburg, Pennsylvania)

p.s. Why are the time stamps different on the Harrisburg cameras? The wide-angle PA Falcon Cam is on Eastern Standard Time (EST); the closeup camera is on Daylight Saving Time (EDT).

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Mar 10 2017

Vaudeville Gulls

It’s Vaudeville time with duets of gulls singing and dancing.

Above, two yellow-legged gulls (Larus michahellis) sing in Europe.

Below, European herring gulls (Larus argentatus) dance in Penzance, UK.

Their acts are serious business.  Gulls sing when they’re courting and dance for their dinner.

You’ll hear lots of gulls singing in the months ahead as they enter the breeding season.

But you’ll be lucky if you find a dancing gull.  In Europe gulls stamp on the ground to bring worms to the surface.  I’ve never seen them do it in North America.  Have you?

 

p.s. I guessed at the identity of the dancing gulls. If you know they’re not herring gulls, please tell me what they are.

(videos from YouTube)

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Mar 08 2017

Graceful

Swallow-tailed kite in flight (photo from Wikimedia Commons)

Swallow-tailed kite in flight (photo from Wikimedia Commons)

We use words like powerful, strong or fierce to describe raptors but this one is different.  The swallow-tailed kite (Elanoides forficatus) is truly graceful.

Named for their beautiful black tails, their flight is so buoyant that they barely flap as they swoop and turn to grab food from the air or the treetops.  They seem to be moving in slow motion and it’s true.  They can fly slowly because their wings and tails are so long.

Swallow-tailed kites live year round in South America but only visit the southern U.S. and Central America to breed. They eat mostly insects which they capture with their feet but supplement their diet with frogs, lizards and nestling birds during the nesting season.

I’ve seen solo kites returning to Florida in late February but my best experience was last month on the Road Scholar birding trip to Costa Rica.  We saw flocks of swallow-tailed kites and they were spectacular!

At a pond near the road to Agua Buena, three kites skimmed the water, drinking and bathing, as graceful as swallows.  They flew so low that we could see the bluish sheen on their backs.  Jon Goodwill photographed them in the flight.

Swallow-tailed kite, bathing (photo by Jon Goodwill)

Swallow-tailed kite, bathing or drinking in flight (photo by Jon Goodwill)

Swallow-tailed kite bathing (photo by Jon Goodwill)

Swallow-tailed kite bathing (photo by Jon Goodwill)

Swallow-tailed kite lifting off from its bath (photo by Jon Goodwill)

Swallow-tailed kite lifting off from its bath (photo by Jon Goodwill)

Later we took a detour … and we were lucky.  Our guide Roger Melendez saw a pair of kites building a nest.  Bert Dudley zoomed his camera for this video of the female arranging the sticks. (You can hear us talking in the background.)

Swallow-tailed Kite making a nest

 

I would love to show you the beautiful flight of these graceful birds. This video of three man-made kites flown by Ray Bethell is the closest approximation.

Swallow-tailed kites are so graceful.

 

(top photo from Wikimedia Commons, bathing and drinking photos by Jon Goodwill, video by Bert Dudley. Click on the images to see the originals)

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Mar 03 2017

Golden Sky Dance

 

Golden eagles (Aquila chrysaetos) are the most widely distributed eagle on earth, found in North America, Eurasia and even northern Africa.

During the nesting season they perform a climb-and-plunge “sky dance” to warn other eagles away from their territory. This video from Cornell Lab shows a spectacular sky dance filmed in the western U.S.

Golden eagles prefer to nest in wide open habitats without humans.  They don’t breed in the eastern U.S., probably because it’s too densely populated.  So when you see the “sky dance” in Pittsburgh you’re watching a male red-tailed hawk claim his territory.

Red-tailed hawks are closely related to golden eagles but neither one of them is related to bald eagles.  Click here to find out why.

 

(video on YouTube from the Cornell Lab of Ornithology channel)

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Mar 02 2017

The Shock of Swan Divorce

Bewick's swans (photo from Wikimedia Commons)

Bewick’s swans (photo from Wikimedia Commons)

On Throw Back Thursday:

Some birds are so faithful to their mates that it’s absolutely shocking when they divorce.  Such was the case with two pairs of Bewick’s swans at Slimbridge in 2010.

Read more here in this vintage article:

Swan Divorce

 

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

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Jan 25 2017

Perpetual Motion

 

Three wild turkeys are stuck in a rut.

They’re doing some circular thinking.

 

(video from YouTube. Click on the video to see the original)

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Jan 19 2017

Birds Wearing Black-n-Gold

Black and yellow birds who flock together in Western Panama (photo composite)

Black and yellow birds who flock together in Western Panama (photo composite)

On Throw Back Thursday:

These birds are wearing black-n-gold!

Just before the Steelers AFC Championship game in 2011 I explained why these black and yellow species tend to flock together.

This Sunday the Steelers are again in the AFC Championship.  What better time to revisit birds wearing black-n-gold.  Read on!

Wearing Black-n-Gold!

 

(composite photo credits, top left to right, then bottom left to right:
1. Slate-throated Whitestart: Corey Finger on 10000birds.com
2. Sooty-capped Bush Tanager: Wikipedia
3. Yellow-thighed Finch: Wikimedia Commons
4. Collared Whitestart: Jan Axel on janbirdingblog.blogspot.com
5. Silver-throated Tanager: Kent Fiala’s Website
6. Yellow-throated Brush Finch: Atrevido1 at Solo Aves on Flickr
)

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