Archive for the 'Nesting & Courtship' Category

Apr 02 2015

Learn About Nests on PBS NATURE, April 8

Just in time for nesting season PBS NATURE premieres their three-part series Animal Homes.  Episode 1 on April 8th is devoted to Nests.

Using time lapse photography, infrared light and tiny HD cameras, the producers got up close and personal during all the stages of nest building.  The Anna’s hummingbird above is just a taste of the beautiful footage and intimate looks at the birds.

Each nest is custom made.  The wonder is that strong, resilient, and intricate nests are woven out of grass and twigs using only a beak.  And some build with mud, sticks or merely leaves:

  • Red ovenbirds (rufous hornero) of South America build an oven-shaped nest entirely of mud with an amazing internal baffle that forces them to squeeze in sideways.  Watch what they do when the cowbirds come.
  • A male osprey attracts a mate while he builds a 400-pound nest from scratch, stick by enormous stick!
  • Male Australian brush turkeys build compost heaps of leaves where multiple females deposit their eggs, as many as 50 eggs per heap.  It doesn’t matter whose kids they are.  The “kids” are self sufficient when they hatch.
  • Chalk-browed mockingbirds battle shiny cowbirds at the nest and sometimes win.

And if you bird by ear, don’t just “watch” the show.  Listen, too!  There’s a message in the soundtrack, the song of a familiar North American bird whose name is a nod to the name of the program.  I thought its voice was misplaced in the South American footage until I read on Wikipedia that “It occurs from Canada to southernmost South America and is thus the most widely distributed bird in the Americas.”

Very cool, PBS NATURE!  I learn something new every day.

Watch Animal Homes: Nests on PBS NATURE, April 8 at 8:00pm EDT.  In Pittsburgh it’s on WQED.


(video from PBS NATURE)

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Apr 02 2015

Dorothy Laid An Egg

Dorothy inspects her egg, 2 April 2015, 6:41am (snapshot from the Naitonal Aviary falconcam at University of Pittsburgh)

Dorothy laid her first egg of 2015 this morning at 6:41 am at the Cathedral of Learning.

At 16 years old she is elderly for a peregrine falcon, so every egg is a miracle.  This is her latest ever first egg date.  In her prime, she always laid in mid March.

Shortly after laying the egg, she called E2 and he came to see.

Dorothy and E2 discuss the first egg (photo from teh National Aviary falconcam at University of Pittsburgh)


7:52am:  E2 brought breakfast for Dorothy. After she left to eat he zoomed in to guard the egg.

E2 arrives to guard the egg (snapshot from the National Aviary falconcam ay University of Pittsburgh)


And here’s a video of the egg laying, thanks to Bill Powers at PixController. There is no color in the video because it happened just before dawn.

Watch Dorothy and E2 here on the National Aviary falconcam at the Cathedral of Learning.

If you’re new to peregrines, click here for information on their nesting habits.  Learn about the color of their eggs and their strategy for incubation.


(snapshot from the National Aviary falconcam at the University of Pittsburgh’s Cathedral of Learning)

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Mar 30 2015

Night Roost

Dorothy roosting at the nest, 29 March 2015 (photo from the National Aviary falconcam at University of Pittsburgh)

Dorothy roosted at the nest last night.  Here she is standing over the scrape with her beak under her right wing.

She’s probably feeling “egg-y.”


(photo from the National Aviary falconcam at University of Pittsburgh, 29 March 2015, 10:16 p.m.)

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Mar 28 2015

Hays Eagle Nest Failed

Female bald eagle lifts eggshell at Hays (screenshot from the Hays bald Eaglecam)

Female bald eagle lifts eggshell at Hays nest, 27 Mar 2015, 5:23am (screenshot from the Hays bald Eaglecam)

If you haven’t heard…

Before dawn on Friday morning March 27 it looked as if the egg in the Hays bald eagle nest was about to hatch.  The pair had had two eggs but one was non-viable and the birds removed it on March 13.

All eyes were on this last egg but by evening it was apparent that it too was not viable. The parents abandoned the nest.

What an abrupt and sad end to the Hay nesting season!

Read more coverage at:


(screenshot from the Hays Bald Eaglecam, installed by PixController)

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Mar 23 2015

Peregrine Quest: Mixed Results

Peregrine Quest view from Flag Plaza, 3/22/15 (photo by Kate St. John)

On Sunday afternoon five of us scoured Downtown Pittsburgh looking for the peregrine falcon pair who haven’t used the Gulf Tower nest since March 10.  They’ve got to be nesting somewhere by now, but where?  Our Peregrine Quest came up with mixed results.

Doug walked Gateway Center/Market Square.  Denise and her husband checked midtown including the 2012-2013 nesting zone. I checked Penn/Liberty and went to the North Shore for a wider view and John English went to Flag Plaza.  Only John saw peregrines and he saw them almost immediately.  (UPDATE: See Doug’s comment below.)

After John texted me with two peregrine sightings back-to-back — one flew past BNY Mellon down the Forbes-Fifth canyon and one perched on UPMC (U.S. Steel Building) —  I raced over to Flag Plaza to see them, too.  I hadn’t been there long before we saw an exciting but silent interaction.

A female peregrine was flying around UPMC and approaching the building again from the left when a male peregrine popped out from behind the building (using it as a blind) and attacked her from above!  She evaded his dive-bombing and sailed around UPMC one more time, then circled up and sailed off toward Oakland.

Here’s a map of the buildings (red pins), the peregrine perch (green pin), our vantage point (brown pin), and the peregrine flight paths during our half hour of watching.   After the attack the male perched on UPMC for a while but we missed seeing him leave.

View Downtown Pittsburgh, Peregrine Tussle, 3/22/15, 2pm in a larger map


Why would a male peregrine attack a female during nesting season?  The only time I’ve seen this happen is when the pair has eggs in the nest, the female is busy at the nest, and a new female shows up.  The male then defends his territory, nest, and mate from an intruding female.  So my guess is that the Downtown peregrines already have a nest.

We learned that they’re spending time at this end of town, but we still don’t know where they’re nesting.


(view from Flag Plaza, photo by Kate St. John with lousy late afternoon light)

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Mar 12 2015

TBT: Conspicuous

Red-tailed hawk soaring (photo by Cris Hamilton)

Throw Back Thursday (TBT):

Red-tailed hawks are conspicuous now as they soar to claim territory and court their mates.

Click here for a timely article from 2009 that describes what they’re doing.

Watch for the male’s Sky Dance.


(photo of a soaring red-tailed hawk by Cris Hamilton)

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Mar 11 2015

Bobble Buffleheads

Spring is finally here and the early birds are on their way north.  Among them are bufflehead ducks whose body shape and courtship behavior would earn them a different name if they needed one today.

Buffleheads (Bucephala albeola) are small black and white ducks that nest in tree cavities from western Quebec to Alaska.  Males are striking black and white, females mostly black, and they’re named buffleheads — “buffalo heads” — because the male’s head looks large and out of scale for his size.

Watch the video above and you’ll see three males “use their heads” to impress the lone female.  They are bobbing like crazy!  Apparently, the bigger the bob the better.

There’s even more going on.  Here’s a list of courtship displays quoted from Cornell’s Birds of North America Online.

  • Head-bobbing is the most common.
  • Fly-over and Land (not seen in the video):  The male flies over the female and lands close to her, skiing on water to show off his feet, raising his head feathers to show off his head.
  • Head-shake-forward:  After landing the male tosses his head forward and …
  • Wing-lift:  … and raises his wings high behind his head.
  • Leading and Following are done by established pairs.  “The male leads by swimming vigorously with the neck stretched upwards, sometimes pecking to the side, and the female usually responds by a Following Display, in which she swims or runs on the surface to catch up with the male, her neck extended, and vocalizes.”

So this lady has a mate (he’s Leading) but it doesn’t stop the other two guys from making a pass.  When one of them is particularly persistent she chases him away but he’s not convinced until her mate chases, too.

Buffleheads court while on migration so you’ll see this behavior on nearby lakes and rivers this month.

Do they make you think of buffaloes when you see their heads?

Nope.  If we had to name them today, we’d call them bobbleheads.


(video by winterwren3 on YouTube)

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Mar 07 2015

Woo Hoo!

Dori and Louie court at the Gulf Tower nest, 6 Mar2015 (photo from the National Aviary falconcam at Gulf Tower)

Yesterday I fretted that Dori and Louie might not nest at the Gulf Tower because they hadn’t been seen there since February 20. I was so concerned that they might be using their old nest site on 3rd Avenue that I went over there at 5:00pm to find them. But no peregrines.

This morning I pulled two motion detection images from the Gulfcam and found out why they weren’t at 3rd Ave.

Here they are after everyone left for the weekend!

Just after 5:50 pm Friday, Louie was moving so fast he was a blur.  :)

Louie lifts off from the nestbox at Gulf Tower (photo from the National Aviary falconcam at Gulf Tower)

Woo hoo!


(photos from the National Aviary falconcam at the Gulf Tower, Pittsburgh)

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Mar 06 2015

What’s Up With These Peregrines?

Magnum perched at Neville Island while her mate flies by, 28 Feb 2015 (photo by Anne Marie Bosnyak)

February and March are great times to watch peregrine courtship in Pittsburgh.  Unfortunately our two sites with webcams — Pitt and the Gulf Tower — have little or no courtship activity.  What’s up with these peregrines?

Nearly every day I visit the University of Pittsburgh to check on Dorothy and E2.  They’re usually perched on the Cathedral of Learning but they don’t make courtship flights like they did in the old days.  This is probably because, at age 16, Dorothy isn’t interested anymore.  She seems to be in “hen-o-pause” since her egg bound episode last spring.

Sadly this means the pair is rarely on the webcam.  Twice last week E2 tried to lure Dorothy to the nest but she visited only once.  This is in stark contrast to her prior habit of sitting at the nest for hours and courting several times a day, even in February snow.  I don’t expect any peregrine chicks while Dorothy is in charge.

At Gulf there’s a beautiful new HD webcam — and no peregrines!  They visited the nest on February 7 and 20 but Ann Hohn at Make-A-Wish confirms what the camera says:  No peregrines have been there for two weeks.  This is highly unusual if they intend to nest at Gulf.  I wondered if they’d gone back to their old 2012-2013 nest site near Point Park University so I checked it last Saturday.  No peregrines there.  No peregrines anywhere Downtown.  What’s up?  I don’t know.

The bright spots have been the bridges.

I’ve only been to the Westinghouse Bridge once this year, but I saw a peregrine perched on it when I drove by on February 22.  At Tarentum I saw both peregrines in courtship flight on nestbox-installation day.  And at the Neville Island I-79 Bridge, Anne Marie Bosnyak saw the peregrines court and mate last Saturday.  They even stayed long enough for Anne Marie to go home for her camera and take these beautiful photos of Magnum and her mate.  Love is in the air at Neville.

Magnum at Neville Island, 28 Feb 2015 (photo by Anne Marie Bosnyak)

So far there are no sightings at the Monaca-East Rochester Bridge, the McKees Rocks Bridge, and the Greentree water tower — though that doesn’t mean there aren’t peregrines.

If you have any news, post a comment to let us know … What’s up with these peregrines?


(photos of Magnum and her mate by Anne Marie Bosnyak)

p.s. Folks in Johnstown are hoping their lone male peregrine on the First National Bank Building attracts a mate soon.

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Feb 28 2015

New Nest Box at Tarentum

Tarentum Bridge nestbox project, The Bucket Truck, 27 Feb 2015 (photo by Kate St. John)

The PennDOT Bucket dips down to the middle pier at the Tarentum Bridge (photo by Kate St. John)

If you saw the peregrine banding at the Tarentum Bridge last May, you’ll remember the nest was in a dangerous place.  The entrance hole pointed down over open water and there were no perches nearby.  After banding the chicks the PA Game Commission placed them on the mid-river pier where they learned to fly in safety.  (Click here to see last year’s site.)

Thinking ahead to this year, it’s no wonder the Game Commission decided to place a nestbox on the bridge. Rob Protz, Marge Van Tassel and I braved 9oF to watch the installation yesterday morning.

Brrr!   Marge took our picture with one of the PennDOT crew.

PennDOT bridge worker + Rob Protz + Kate St. John (photo by Marge Van Tassel)

PennDOT bridge worker, Rob Protz and Kate St. John at Tarentum Boat Ramp, 27 Feb 2015 (photo by Marge Van Tassel)

Before the installation began we saw two peregrines!

Around 9:00am the female 69/Z, nicknamed Hope, flew from the bridge.  Rob Protz saw her land in a tree so we went over and Marge took her picture.  (This was one of the few times I’ve ever seen a peregrine perched in a tree.)  Within a half hour, Hope’s mate came by for a courtship flight and the pair disappeared upriver.

Female peregrine, Hope, perched in a tree in Tarentum, 27 Feb 2015 (photo by Marge Van Tassel)

Female peregrine, Hope, perched in a tree in Tarentum, 27 Feb 2015 (photo by Marge Van Tassel)

Meanwhile PennDOT District 11 blocked a lane of traffic on the bridge, set up the Bucket Truck, and delivered PA Game Commission biologist Tom Keller to the catwalk.  While he climbed down the ladder to the mid-river pier, Hope returned and noticed something was up. She watched the project from the upriver navigation light.

Female peregrine, Hope, watches the nestbox project from the upriver navigation light (photo by Marge Van Tassel)

Female peregrine, Hope, watches the nestbox project from the upriver navigation light (photo by Marge Van Tassel)

The Bucket delivered tools, gravel and the new nestbox to Tom.

Tom Keller guides the nestbox as it drops from The Bucket Truck (photo by Marge Van Tassel)

Tom Keller guides the nestbox as it drops from The Bucket Truck (photo by Marge Van Tassel)

While he cleared ice from the pier he was joined by another member of the PennDOT crew.

PGC's Tom Keller and  PennDOT worker installing nestbox on Tarentum Bridge (photo by Kate St. John)

PGC’s Tom Keller and PennDOT worker install nestbox at the Tarentum Bridge (photo by Kate St. John)

They positioned the box with its back to the prevailing wind, drilled holes to anchor it, added a perch pole, and filled it with gravel.

Tarentum Bridge nestbox (photo by Tom Keller)

Tarentum Bridge nestbox (photo by Tom Keller, PA Game Commission)

Ta dah!

Tom Keller, PGC, and PennDOT worker District 11 next to new peregrine nestbox on the Tarentum Bridge (photo from Tom Keller)

Tom Keller and Steve from PennDOT with new peregrine nestbox at Tarentum Bridge (photo from Tom Keller)

Now we wait and see, and hope that “Hope” will use it this year.


(photos by Marge Van Tassel, Kate St. John and Tom Keller.  See captions for photo credits)

p.s. Steve, picture above on the bridge with Tom, is the one who built the box of cedar to PGC’s specification.

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