Mar 25 2015

Dorothy Then And Now

Published by under Peregrines

Dorothy, March 2010 and March 2015 (photo from the National Aviary falconcam atUniversity of Pittsburgh)

Many of you are looking forward to Dorothy having eggs and chicks this spring at the Cathedral of Learning.  Others, knowing her age, have asked about her status.  Today I’ll explain her condition and why you should not be surprised when she doesn’t have viable eggs this year.

Dorothy is 16 years old, elderly for a wild peregrine.  Her fertility dropped to a single fledgling in 2013 and collapsed in 2014 after she became egg bound.  In the top photo she was sleek and alert in her fertile years (photo from 2010).  In the second photo, she is rumpled and slow moving now.  Consistently rumpled feathers are an indication of ill health in birds.

I have watched Dorothy since 2001 when she was only two years old.  For more than a decade she was full of vitality, totally in control.  She only began to hint at her age in 2013.  This year her decline is pronounced.  There are differences in her behavior that tell me she is past her prime.

THEN: 2001 to 2013 NOW: 2014 and 2015
Many courtship flights including aerial prey exchange in January, February, March No courtship flights in 2015. No aerial prey exchange since 2013.
Perching and mating(!) on the lightning rod on top of the Cathedral of Learning Has not been on the lightning rod. Has not been seen mating this spring.
Laid down only to incubate. (Peregrines roost and sleep in a standing position) Lies down to sleep in nest though there are no eggs
Agile at all times Opens wings to steady herself while walking on nest rail. Is slow moving
Always perched above the 27th floor. Rarely perched on A/C units Perches as low as 12th or 13th, often on A/C units.
Sleek feathers, alert stance Rumpled rough feathers, hunches more often

 

When I see her lying down in the nest without any eggs, I worry.  This is an unnatural position for a peregrine falcon that isn’t incubating.

Dorothy sleeping on her belly, though she has no eggs (photo from the National Aviary falconcam at Univ of Pittsburgh)

 

For now Dorothy is staying close to home. She is often seen on camera or perched at office windows, gazing in.  These are endearing traits that make us love her more, but that does not change the fact that she is elderly.

Dorothy’s chances of producing healthy peregrine chicks this year is very slim.

 

(photos from the National Aviary falconcam at University of Pittsburgh)

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Mar 24 2015

The Scouts Are Coming

Adult male purple martin (photo by Cajay on Wikimedia Commons)

You know Spring has sprung when the swallows return.  Tree swallows arrive first (seen in Allegheny County already!) but soon the bravest purple martins return from Brazil.  Though they rely on flying insects for food, adult males are so anxious to begin breeding that they fly home as soon as they can.

Purple martins (Progne subis) are cavity nesters with a long term relationship to humans.  Native Americans first provided nesting gourds and European immigrants followed suit so that now, for more than 100 years, all the purple martins in eastern North America nest in human provided housing.

Purple Martin house, Cape May Point, NJ (photo from Wikimedia Commons)

Last Thursday at Wissahickon Nature Club Bob Allnock, a purple martin landlord from Butler County, taught us about the housing and habits of these amazing birds.  We learned that the same purple martins return year after year to their successful nest sites.   The earliest males get the best condos so they hurry to get home.  The landlords call them “scouts.”

Scouts are always adult males who’ve bred before and know exactly where they’re going.  Adult females return later and then, weeks later, the subadult males and females arrive.  They’re in their first year of breeding and haven’t found a home yet.  If you’re trying to establish a new purple martin colony, these are the birds you wait for.

Right now purple martin landlords in western Pennsylvania are anxiously awaiting their first scouts.  As soon as one arrives the landlord updates the Purple Martin Conservation Association (PCMA) website with the date and location.  They also update when they see the first subadults so that landlords of unoccupied colonies can be on the lookout to attract these new birds.

How far north has Spring advanced? Where are they scouts right now?  Click here on the PCMA website for the Scout Report.

 

(photos from Wikimedia Commons. Click on the images to see the originals)

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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)

9 responses so far

Mar 23 2015

Reminder: March 29 Outing at Schenley Park

Published by under Books & Events

Coltsfoot blooming (photo from Wikipedia under GNU Free License) Just a reminder that I’m leading a bird and nature walk on Sunday March 29, 8:30am in Schenley Park.  Meet at Bartlett Shelter.
(Note that Schenley Drive is closed until 9:00am for CMU Buggy Race practice.)

Click here for more information and for updates if the walk is canceled for bad weather.

Maybe we’ll see coltsfoot.

 

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

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Mar 22 2015

Birds As Musical Notes

Published by under Beyond Bounds

Birds on wire (photo from Wikimedia Commons)

Bird photography can be disappointing.  It’s difficult to get depth without good lighting, but every once in a while two dimensions are stunning and an eye for cropping is all you need.

This photo of brown-headed and/or bronzed cowbirds in Silao, Mexico looks like musical notes.  Can you play this tune?

 

Click here to see the original uncropped photo, and here to see this exceptional one in larger format on Wikimedia Commons.

(photos from Wikimedia Commons.  Click on the links to see the originals)

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Mar 21 2015

Analemma

Published by under Weather & Sky

Analemma photo taken 1998-99 ourside Bell Labs in NJ by Jack Fishburn (GNU free licensing, Wikipedia)

The word Analemma sounds like a girl’s name or perhaps an exotic fruit but in fact it’s the name for that figure 8 hanging in the sky above.  You won’t see it in Nature but you may have seen it as a symbol printed on an old-fashioned globe of the world.

Technically speaking an analemma is the location of one celestial body as viewed from another for one complete orbit.  Practically speaking it’s the Sun’s position throughout the year at the same location and time of day on Earth.   I was surprised to learn it’s a figure 8 but that’s because the Earth’s orbit is elliptical and tilted.

This photo took a whole year to create.  Every other week in 1998-1999, Jack Fishburn took a photograph of the sun’s position from his office window at Bell Labs.  He was careful to place the camera in the exact same position and snap the photo at the same time of day (correcting back to Standard Time during Daylight Savings).  After collecting a year of photographs he overlaid them to create the analemma.

Tunc Tezel did the same thing at Baku, Azerbaijan and made it a movie here.

You can create your own analemma if you’re persistent (one whole year) and precise (same camera location and time of day for every photo) and have access to Photoshop.

When you’re done you’ll know that the top of the 8 is the summer (northern) solstice, the bottom is the winter (southern) solstice, and the crossover point is both equinoxes.  Today, one day after the Northern Equinox, the sun is very near the center of the analemma.

 

(photo by Jack Fishburn via Wikipedia GNU Free License. Click on the image to see the original)

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Mar 20 2015

Peregrine Quest! March 22, 1pm, Downtown

Empty Gulf Tower nest, 19 March 2015 (photo from National Aviary falconcam at Gulf Tower)

The empty nest at the Gulf Tower, Downtown Pittsburgh

They’ve done it again!  The Downtown peregrines have been absent from the Gulf Tower since March 10 … yet they have been seen Downtown.

Apparently they are planning to nest somewhere else … but where?  Let’s find out.

Join Pittsburgh Falconuts on our quest to find the Downtown peregrines.  We’ll meet on Sunday March 22 at 1:00pm at the Dunkin’ Donuts at 28 Market Square and fan out from there.

If you can’t make it, wish us luck.  We’ll need it!

 

Thanks to John English of the Pittsburgh Falconuts Facebook page for organizing this quest.

(photo of the empty Gulf Tower nest from the National Avairy falconcam)

 

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Mar 20 2015

Today, Stonehenge At Home

Stonehenge (photo from Wikimedia Commons in the public domain)

Throw Back Thursday (TBT) is a day late in honor of the Spring Equinox.

During today’s sun event there will be a Stonehenge effect in my neighborhood.

Click on the link to learn how the position of our houses causes Stonehenge At Home.

 

(photo of Stonehenge in the public domain via Wikimedia Commons. Click on the image to see the original)

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Mar 19 2015

The Crocus Report

Published by under Phenology,Plants

Crocuses at Phipps, 18 March 2015 (photo by Kate St. John)

Ta dah!  We’ve reached a milestone in The Signs of Spring.  It’s time for the crocus report.

Yesterday morning the crocuses at Phipps Conservatory’s outdoor garden were just about to pop open.  The bright sun warmed the mulch and after another hour they had opened halfway.  I can say with confidence that they bloomed on March 18.

Crocuses opening at Phipps (photo by Kate St. John)

Is this late for crocuses?   I checked back through my blog posts, linked below, to collect their blooming history in Pittsburgh’s East End:

So … though this winter has seemed very cold the crocuses are not delayed too, too long.

 

(photos by Kate St. John)

p.s. They may have bloomed during Monday’s heat but I didn’t walk over to Phipps until yesterday.

7 responses so far

Mar 18 2015

Listening To The Secret Sounds Of Trees

Woman listening with headphones (photo from Wikimedia Commons)

In early May when the trees leaf out we’ll once again hear the soothing sound of rustling leaves.  Did you know trees make sounds we cannot hear?

Last year an article by Sarah Zhang in Gizmodo caught my attention.  Eavesdropping On The Secret Sounds Of Trees describes the art and science of a Swiss research team who’s recording the internal sounds of trees.

The project, fittingly called trees, attaches sensitive microphones to trunks, branches and even leaves, then records the sounds and analyzes them in light of simultaneous environmental factors such as drought.  Click here and scroll down to hear the clicks, pops, hisses and taps made by a Scots pine (Pinus sylvestris).

Closer to home our trees are getting ready for spring, the sap is running, and it’s maple sugaring time in North America.

Maple sugar bucket hanging on a tree (photo from Wikimedia Commons)

And so I wonder …

If we had those special microphones could we heard the sap rising in the maples?  Or is it so loud that we can hear it by putting our ears to the trees?

I’ll have to see.

 

(photos from Wikimedia Commons. Click on the images to see the originals)

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