Archive for the 'Bird Behavior' Category

Jul 22 2016

Purple Martins: Faithful to Home

Purple martin fledgling opens wide for dad (photo by Donna Foyle)

Purple martin fledgling opens wide for dad (photo by Donna Foyle)

Last Saturday fourteen of us joined purple martin landlords and their families at Bob Allnock’s annual Purple Martin Night where we learned about the birds and heard news of their success.

Click here for the slideshow that illustrates this article.

Purple martins (Progne subis) are North America’s largest swallow and the only bird that relies on man-made housing for its nest.  The western population still uses woodpecker holes but eastern purple martins made the switch long ago to nest colonially in apartments and man-made gourds provided by human landlords.

Purple martin houses at Bob Allnock's (photo by Kate St. John)

Purple martin houses at Bob Allnock’s (photo by Kate St. John)

The landlords provide housing and protection and the martins return faithfully every year.  The dark blueish purple males arrive first — in April in western Pennsylvania — followed by the adult females with dark backs, light bellies and gray collars.  The adults claim their favorite nest sites before the speckled sub-adults arrive.

Purple martins eat only flying insects and are especially fond of dragonflies.  To catch them they feed higher in the sky than other swallows.  We didn’t think the martins were anywhere near us until we looked up at the clouds with our binoculars and saw them wheeling as much as 500 feet above.

Female purple martin with food for her nestlings (photo by Donna Foyle)

Female purple martin with food for her nestlings (photo by Donna Foyle)

By mid-July many of the young martins in Bob’s colony had already fledged but they still begged from their parents.   The (approx) 80 nest sites were humming with activity as the adults fed youngsters, took out the garbage (fecal sacs), and sometimes even tussled at the nest holes.  One youngster (see him in gourd #2) fledged while we were there.

Like all birds, purple martins are vulnerable to nest predation and a variable food supply. Fortunately they have dedicated landlords who …

  • Check the nests to make sure all is well. In the slideshow notice the circular access lid on the gourds. Bob Allnock can also watch three nests on nestcams.
  • Protect the nests from starlings by providing M-shaped holes that only purple martins can use.
  • Thwart raccoons and snakes who climb the poles to raid the nests.  Bob Allnock has wrapped the base of his poles with live electric wiring (“electric fence”).  One shock is all it takes!
  • Scare off great horned owls who raid from the air.  Bob turns on a yellow “air dancer” at dusk.  He moves it to a new location every night so the owls don’t get wise to it.
  • Provide supplemental feeding during prolonged wet weather when the bugs don’t fly. Purple martins starve without these feedings.

And the weather has cooperated.  This year’s fledglings are doing well in western Pennsylvania’s dry weather, especially after three wet years in a row.

Until their young have learned the ropes the purple martins stay at the colony.  At dusk they return to spend the night inside the nests.

In September they’ll leave for Brazil and their landlords will wait through the long quiet winter for their faithful purple martins to come home.

Click here for a slideshow of the event.

 

(All the purple martin close-ups are by Donna Foyle. House photos by Kate St. John.  Image of yellow inflatable air dancer from Amazon.com)

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Jul 15 2016

Old Home Week for the Downtown Peregrines

Dori and Louie bow at the Gulf Tower nest, 14 July 2016, 3:48pm (photo from the national Aviary falconcam at Gulf Tower)

Dori and Louie bow at the Gulf Tower nest, 14 July 2016, 3:48pm (photo from the national Aviary falconcam at Gulf Tower)

Yesterday (July 14) was Old Home Week for the Downtown peregrines as they toured all the places they’ve nested since Dori arrived in Pittsburgh six years ago.

Around 7:30am Lori Maggio saw “an adult peregrine, Dori I assume, preening on the 3rd Ave nest ledge. Then she entered the nest.”  The photo below from last May gives you an idea of what Lori saw. The peregrines nested here in 2012, 2013 and this year, 2016.

adult peregrine at entrance to Third Ave nest in May 2016 (photo by Lori Maggio)

Adult peregrine at entrance to Third Ave nest in May 2016 (photo by Lori Maggio)

 

At 10:55am Dori and Louie visited their 2015 nest at the old Macy’s Annex.  Matt Digiacomo, who captured these photos, says the area is under renovation.  The door is open on the balcony behind Dori so she’s not likely to nest here.  Perhaps she was curious.

Dori visiting her 2015 nest site at the former Macy's Annex, 14 Jul 2016 (photo by Matt Digiacomo)

Dori visiting her 2015 nest site at the former Macy’s Annex, 14 Jul 2016 (photo by Matt Digiacomo)

And perhaps Louie was curious, too.  While Dori checked out Macy’s, he perched at his usual overlook on the Union Trust Building.  I’m sure he’s glad the Union Trust scaffolding is gone.

Louie at his usual perch on the Union Trust Building, 14 July 2016 (photo by Matt Digiacomo)

Louie at his usual perch on the Union Trust Building, 14 July 2016 (photo by Matt Digiacomo)

 

Finally at 3:48pm the pair rounded out their tour with a bowing visit to the Gulf Tower, at top.  Dori nested here in 2010, 2011 and 2014.

All of Dori’s predecessors — and Dori herself — used the Gulf Tower continuously from 1991-2011.  It’s a mystery why she’s so nomadic.

 

(photos from the National Aviary falconcam at Gulf Tower, Lori Maggio and Matthew Digiacomo)

 

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Jul 11 2016

A Bird With A Bad Pick-up Line

This 3-note song mystified me in my own backyard.  I can usually identify birds by ear but this one stumped me for at least six weeks.

Finally, I recorded it outside my window and sent it to my friend Dr. Tony Bledsoe.  Tony suggested a tufted titmouse. (Turn up your speakers to hear the song in the video above. Ignore the picture, the bird’s not in it.)

A few days later I saw the bird.  No wonder we didn’t recognize the song!  He’s a gray catbird that sounds nothing like his cohorts.  (Turn your speakers back down for the audio below.)

 

Most birds are silent in early July but the odd-sounding gray catbird is still singing in my neighborhood and I can guess why.

None of the lady catbirds like his song so he’s still calling for a mate.

He’s a bird with a bad pick-up line.

 

(video by Kate St. John)

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Jul 05 2016

Hope’s in Charge For Now

Hope and Terzo band colors showing, 4 July 2016(photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope and Terzo with band colors showing, 4 July 2016 (photo from the National Aviary falconcam at Univ of Pittsburgh)

A lot has happened at the Cathedral of Learning peregrine nest in the past two weeks.

  • On June 21 a new female peregrine, Magnum, appeared on the falconcam. She came to the nest several times through June 23 and bowed with Terzo, the resident male. Her presence meant that the previous female, Hope, was gone.
  • At midday June 24 Hope returned to the nest and has been bowing with Terzo ever since.
  • On June 27 this year’s fledgling, C1, visited the nest and made loud begging sounds.
  • On July 2, Chad Steele photographed Magnum at her own nest site, the Neville Island I-79 Bridge.

During these changes I was off the grid and couldn’t answer your questions.  Here are some long awaited answers.
.
Did anyone see Hope and Magnum fighting?

No. We never saw anything, stuck on the ground with our poor field of view.  My guess is that Hope and Magnum chased each other without making physical contact.

I see two peregrines at the nest. Please tell me if it’s Hope and Magnum and if they are fighting.

Magnum is gone for now.  However, you can tell the difference between courtship and fighting by observing the birds’ postures and actions:

Courtship: 2 peregrines standing apart from each other and bowing low = male+female strengthening pair bond.

Fight: 2 peregrines with talons locked (feet are connected), trying to peck at each others’ throats, wings open, leaning backwards to avoid each others’ beaks = 2 birds of the same sex fighting.  Here’s a slideshow of a fight in 2007 between two males at the Cathedral of Learning.

Why are the females competing now outside the nesting season? Are they competing for Terzo?

They’re not competing for Terzo at all.  They’re competing for the Cathedral of Learning, a prime nest site worth winning at any time of year. It’s better than a bridge.

Does Terzo’s preference determine which female wins?  Since Hope was there first, will Terzo leave if he prefers Magnum?

No. Unlike humans who bond with their mates and then find a place to live, peregrines bond to the nest site and then mate with whoever is there.  If another female wins the site — no matter who it is — Terzo will mate with that female. He will not leave the site unless a new male ousts him.

Will Hope keep the Cathedral of Learning site?

We don’t know.  We can tell that Hope is a weak owner because other females have made it to the nest three times in April & June.  A strong owner would never let other females get into the nest.  It never happened during Dorothy’s reign.

Has anyone seen Magnum recently?

Yes. On July 2 Chad Steele, peregrine monitor from Canton, Ohio, photographed Magnum at her home nest site, the Neville Island I-79 Bridge.  His photos confirm her identity.

Magnum at the Neville Island I-79 Bridge, 2 Jul 2016 (photo by Chad Steele)

Magnum at the Neville Island I-79 Bridge, 2 Jul 2016 (photo by Chad Steele)

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How is this year’s fledgling, C1?

C1 is so mobile that it’s hard to keep track of her.  Anne Marie Bosnyak saw her this morning, July 5, on St. Paul’s steeple.  We also know she visited the nest on June 27, whining loudly. Is she as loud as her mother? Perhaps.

C1 visits the nest, 27 June 2016 (photo from the National Aviary falconcam at Univ of Pittsburgh)

C1 visits the nest, 27 June 2016 (photo from the National Aviary falconcam at Univ of Pittsburgh)

 

p.s. As you watch the falconcam, here are band colors and numbers to look for:
Hope: black/green 69/Z + Green on right leg
Terzo: black/red N/29 + Silver on right leg
Magnum: black/red 62/H + Purple on right leg
C1 (juvenile, brown and cream-colored plumage): black/green 06/BR + Silver on right leg

(nest photos from the National Aviary falconcams at Univ. of Pittsburgh. photo of Magnum in flight by Chad Steele)

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Jun 28 2016

There’s A Lot Less Singing

Yellow warbler (photo by Chuck Tague)

Yellow warbler (photo by Chuck Tague)

It happens every year. By late June, birds are singing a lot less than they did a month ago. By mid July most birds are silent.

Find out why they stop singing in this article: Becoming Silent.

 

(photo by Chuck Tague)

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Jun 21 2016

The Bird Who Sings All Night

Northern mockingbird, singing with wing flash (photo from Wikimedia Commons)

Northern mockingbird, singing and wing flashing (photo from Wikimedia Commons)

This month someone in my neighborhood complained he was kept awake at night by birds singing loudly in the dark.  Every song was different so he thought it was a variety of birds.  Who was making that racket?  It was only one northern mockingbird.

Mockingbirds are well known for nocturnal singing.  The majority of those who do it are lonely bachelors trying to attract a female.  They belt out their songs as loudly as possible in all directions and they prefer to do it at the most aggravating time for humans — midnight to 4:00am.  Studies have shown they sing more on moonlit nights and in well-lit areas.  Woe to city and suburban dwellers near street lights!

The video below, recorded at 2:00am, is understandably dark. The bird is exceptionally loud.

Over at my house there’s a mockingbird who’s definitely lonely!  Will he ever stop?

Birds of North America Online says:  “Typically, adults sing for approximately three fourths of the year (Feb through Aug, and late Sep to early Nov); occasionally sing during winter. … No nocturnal song occurs during the fall.”

So we wear earplugs to bed and pray that the mockingbird finds a mate.  Or we’ll have to wait until August.

 

(photo from Wikimedia Commons. Click on the image to see the original. Mockingbird audio by SevereTStormFan on YouTube)

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Jun 16 2016

Life Skills for Young Peregrines

Prey exchange between an adult peregrine and his fledgling (photo by Kim Steininger)

Prey exchange between an adult peregrine and his fledgling (photo by Kim Steininger)

On Throw Back Thursday (TBT):

Just three days after fledging, young peregrines fly so well that we lose track of them as we watch from the ground.  They’re already learning the aerial skills they’ll use for the rest of their lives.

Read more about their education in this Throw Back Thursday article: Life Skills.

 

(photo by Kim Steininger)

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Jun 05 2016

Unusual Bird In The Mirror

Protonotary warbler "stuck in a car mirror" (screenshot from video by waterwarbler on Flickr)

Prothonotary warbler “stuck in a mirror” (screenshot from video by waterwarbler on Flickr)

I’ve seen robins, cardinals and mockingbirds attack car mirrors but never this!

Last Thursday waterwarbler captured video and photos of a prothonotary warbler fighting with his own reflection in DuPage County, Illinois.  Click on the screenshot above to see the video.  (Note: When another vehicle drives by the warbler is fine. He moves to the hood of the car.)

And check out this photo of warbler reflections: “Suddenly lots of PROWs“.   No wonder the bird is confused.

 

(screenshot from a video by waterwarbler on Flickr)

p.s. “PROW” is the four-letter code for prothonotary warbler.

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May 20 2016

The Blue Jay’s Courtship Sounds

Blue jays are making interesting sounds and gestures lately but what do they mean?

In the spring I often hear blue jays say “tweedle” and, on rare occasions, I see one bounce and gurgle.

Tweedle? Gurgle?  Lesley the Bird Nerd explains it all in this 4-minute video.

 

(video by Lesley the Bird Nerd on YouTube)

 

 

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May 18 2016

More Robins, Fewer White-throated Sparrows

American robin, white-throated sparrow (photos by Marcy Cunkelman)

American robin, white-throated sparrow (photos by Marcy Cunkelman)

We humans are starting to respond to climate change. The birds already have.

In a study on two continents — North America and Europe — data from 1980 to 2010 shows that populations of our common birds have been affected by climate change and the gap is growing.  Bird species expected to do well due to climate change have substantially outperformed those expected to do badly over the 30 year period.  It’s the first real demonstration that climate is having a similar, large-scale influence on the abundance of common birds in widely separated parts of the world.(*)

Here are two examples from North America:

American robins are an adaptable species whose range has expanded as the climate warms.  Robins don’t have to go as far south in the winter and now they breed in Alaska!

White-throated sparrows are a common winter species in the Lower 48 but when it comes time to breed they’ll be in trouble.  As they move north the forest they require for breeding gives way to treeless landscapes.  It takes decades to grow a forest and climate is changing faster than the plants can catch up.  White-throated sparrows are losing ground.  Click here to see their changing map.

More robins, fewer white-throated sparrows.  The populations of common birds are affected by climate change.

Read more about the study here in Science Daily(*).  See Audubon’s climate website for details on North American birds.

 

(photos by Marcy Cunkelman)

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