Archive for the 'Bird Behavior' Category

May 31 2017

An Uneasy Truce

Published by under Bird Behavior,Mammals

Curve-billed thrashers and round-tailed ground squirrel eating mealworms, Tucson, Arizona (photo by Donna Memon)

Curve-billed thrashers and ground squirrel near Tucson, Arizona (photo by Donna Memon)

In Arizona:

These species tolerate each other at the feeder but their relationship is rocky elsewhere.

In Donna Memon’s backyard two curve-billed thrashers wanted this round-tailed ground squirrel to step away from the mealworms.  Though they poked her she wouldn’t leave. This squirrel is so feisty that she chased a roadrunner!

Away from the feeders it’s all out war. Ground squirrels raid bird nests to eat eggs and nestlings.

Curve-billed thrashers try to avoid predation by nesting in cholla cactus.

Cholla cactus with bird nest (photo from Wikimedia Commons)

Cholla cactus with bird nest (photo from Wikimedia Commons)

 

Steve Valasek found an occupied nest at Hassayampa River Preserve northwest of Phoenix.

Curve-billed thrasher nest in cholla cactus (photo by Steve Valasek)

Curve-billed thrasher nest in cholla cactus (photo by Steve Valasek)

Safe from ground squirrels, heat is the big problem at the cactus nest sites.

Curve-billed thrasher and chick pant in the hot nest (photo by Steve Valasek)

Curve-billed thrasher and chick panting in hot nest (photo by Steve Valasek)

 

How do the chicks fledge?  Very carefully!

 

(photo credits:
curve-billed thrashers with ground squirrel by Donna Memon
cholla cactus photo from Wikimedia Commons; click on the image to see the original.
curve-billed thrashers’ nest by Steve Valasek
)

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May 12 2017

Falcons Help Farmers

How Falcons Protect Vineyards (screenshot from CBS)

How Falcons Protect Vineyards (screenshot from CBS. Click on the image to see the video)

If you grow a crop that tastes good to birds how do you protect it?  Hire a falcon!

Last month CBS News featured a video about an innovative way to chase starlings out of a vineyard.  The falcon in the video was specifically raised as a falconry bird.  It’s a hybrid gyrfalcon-peregrine.

Click here or on the screenshot above to see “How falcons protect vineyards” on CBS News.

Note: There are 15 seconds of promotional video ahead of the falcon piece.

 

(screenshot from CBS News. Click on the image to watch the video)

5 responses so far

Apr 30 2017

The Theories Are Worse Than The Furies

Hope sheltering three nestlings, 29 April 2017, 11:55a (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

Hope sheltering three nestlings, 29 April 2017, 11:56a (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

So far so good.  The three nestlings at the Cathedral of Learning are all well fed and growing. Every day we gain more confidence that they’ll thrive.

Meanwhile we’re still puzzled why their mother, Hope, killed and ate the first-hatching chick as well as two of her four chicks last year.  We don’t know the answer but we have many theories.  It reminds me of a famous quote from Flannery O’Connor in Habit of Being (p. 502):

“The Theories are worse than the Furies.”

So who are the Furies?

According to Wikipedia, the Erinyes [also called the Furies] are ancient Greek goddesses from the underworld. They hear complaints brought by mortals against the insolence of the young to the aged, of children to parents, of hosts to guests, and of householders or city councils to suppliants.  They punish those crimes by hounding the culprits relentlessly and hitting them with brass-studded scourges.  Their victims die in torment.

Their most famous gig was to torment Orestes for killing his mother Clytemnestra who had an affair and killed his father Agamemnon. Orestes avenged his father’s murder but created a really big mess (read more here).  John Singer Sargent’s painting of Orestes Pursued by the Furies shows how awful the Furies can be.

Orestes Pursued by the Furies by John Singer Sargent (reproduction from Wikimedia Commons)

Orestes Pursued by the Furies by John Singer Sargent (reproduction from Wikimedia Commons)

The Theories can be relentless, too.

We have lots of theories about Hope but no data to confirm or disprove them. (Hope eats the evidence.) The only thing we know is that she has repeated the behavior two years in a row and it’s so abnormal that we can find only a handful of similar incidents in all the history of peregrine nest monitoring.

We don’t have an answer but we can make ourselves crazy.

The Theories are worse than the Furies!

 

(photo of Hope and chicks from the National Aviary falconcam at the University of Pittsburgh. Reproduction of John Singer Sargent’s “Orestes Pursued by the Furies” from Wikimedia Commons; click on the image to see the original)

18 responses so far

Apr 27 2017

Three Nestlings At Pitt

Hope prepares to feed 3 nestlings at the Cathedral of Learning, 27 Apr 2017, 8:06a (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope prepares to feed 3 nestlings at the Cathedral of Learning, 27 Apr 2017, 8:06a (photo from the National Aviary falconcam at Univ of Pittsburgh)

Yesterday at sunset there were two chicks and one egg at the Cathedral of Learning nest.  This morning there are three chicks.

Last night Deane posted a comment, “I missed the action prior, but Hope is eating the final eggshell. 21:10.”

The motion detection snapshots show Hope manipulating and eating an eggshell at 9:04pm but the photos are too dark to see if she ate the chick as well.  We had to wait for daylight to find out.

Hope manipulates the 4th egg, 26 April 2017, 9:04p (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope manipulates the 4th egg, 26 April 2017, 9:04p (photo from the National Aviary falconcam)

Hope manipulates empty eggshell of 4th egg, 26 April 2017, 9:07p (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope holds the empty shell egg #4, 26 April 2017, 9:07p (photo from the National Aviary falconcam at Univ of Pittsburgh)

 

This morning at 8am Terzo delivered a woodpecker for breakfast.  As Hope prepared to feed the chicks, we could see three tiny heads.

Hope prepares to feed 3 nestlings at the Cathedral of Learning, 27 Apr 2017, 7:56a (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope prepares to feed 3 nestlings at the Cathedral of Learning, 27 Apr 2017, 7:56a (photo from the National Aviary falconcam at Univ of Pittsburgh)

 

Last year Hope’s infanticide activity was confined to the hatching process.  Perhaps we can watch the Cathedral of Learning falconcam now without dread.

 

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

54 responses so far

Apr 25 2017

One Killed, One Spared

Hope picks up her first-hatching egg. Latr she kills and eats it (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope picks up her first-hatching egg, 24 Apr 2017, 6:15pm. Later she kills and eats it (photo from the National Aviary falconcam at Univ of Pittsburgh)

I recently cautioned viewers about watching the Cathedral of Learning falconcam because the female peregrine killed and ate some of her young last year as they hatched.  I didn’t know if she would repeat this behavior. Last evening she did.

The first sign that Hope would kill the hatchling was around 6:15pm when she picked up and carried the hatching egg (above).  Carrying is not normal.  Half an hour later she killed and ate the chick and its eggshell.

Hope and her behavior were new to us last year.  We didn’t know if she killed and ate some of her young because she was under many stresses:  a new home at the Cathedral of Learning + loss of her mate + finding a new mate + other females challenging her while she was incubating the eggs.

This year none of those stresses apply.  None of them.  And yet Hope killed and ate her first hatchling last evening.

Last year one chick survived.  This morning it appears that Hope has spared the second chick.

Hope with her second chick, 25 April 2017, 6:14am (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope with her second chick, 25 April 2017, 6:14am (photo from the National Aviary falconcam at Univ of Pittsburgh)

Here’s a snapshot showing there are no longer four eggs/chicks.  Now there are only three.

Only 3: 1 chick, 2 eggs, 25 Apr 2017 (photo from the National Aviary falconcam at Univ of Pittsburgh)

Only 3: 1 chick, 2 eggs, 25 Apr 2017 (photo from the National Aviary falconcam at Univ of Pittsburgh)

But the chicks and eggs aren’t safe yet.  The remaining two eggs might succumb and last year when a second chick hatched successfully, it died within a week.  It failed to thrive.  Some speculated that Hope starved it.

We don’t know why Hope does this but we now know it’s not a one-time event.  She may have done this all her adult life but there was no camera at her former nest site, the Tarentum Bridge, where she fledged 0-to-2 young per year.

What’s next?

A Caution to Viewers:

Again, do not watch the Cathedral of Learning falconcam if it upsets you to see a mother kill her young.  The Gulf Tower in downtown Pittsburgh has a beautiful peregrine family with three chicks.  Please watch the Gulf Tower falconcam to learn about normal peregrine behavior!

A Caution to Commenters:

Though this situation resembles reality TV in which viewers can vote someone on or off the island, it is not a “voting” situation.  If commenters become worked up and demand/request action in emails or phone calls to “those in charge” it will end the show.  Literally.  It will shut down the camera.  That’s what happened when commenters went over the top at the Woods Hole Osprey-cam.

Normally I do not edit readers’ comments but this situation is not normal.  If you post a comment that could inflame others, I will edit it or delete it.

Though I am not watching Hope closely (I don’t want see her kill her young), I do want the camera to stay up.

 

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

P.S. on the subject of names:  At the Cathedral of Learning we use “C + Hatch Number” as the naming scheme for chicks.  Last year had 4 chicks (C1 through C4) but only C1 survived.  This year C5 was eaten, C6 is the now live chick.  I will write more about names in the days ahead.

 

 

80 responses so far

Apr 03 2017

Missing Something?

Northern mockingbird missing his tail, near Phipps Conservatory, March 2017 (photo by Kate St. John)

Northern mockingbird missing his tail, near Phipps Conservatory, March 2017 (photo by Kate St. John)

There’s a bossy northern mockingbird near Phipps Conservatory who shouts his song and chases all the birds but he’s missing something — his long expressive tail.

Tails are used in flight, of course, but they’re also an important communication tool for mockingbirds.

“Look at me!” says the mockingbird as he struts with his tail cocked up, wags it to one side during confrontations, and fans it in his parachuting flight display.

Without a tail he looks silly, drooping his wings while he raises his tiny tail coverts. So far the ladies aren’t impressed.

Tail-less northern mockingbird near Phipps Conservatory, March 2017 (photo by Kate St. John)

Tail-less northern mockingbird near Phipps Conservatory, March 2017 (photo by Kate St. John)

I wonder how long it will take to grow back his tail.

For courtship purposes, it better be soon!

 

(photos by Kate St. John)

7 responses so far

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.)

4 responses so far

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)

19 responses so far

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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