Archive for the 'Bird Behavior' Category

Aug 29 2016

Peripatetic

Hope (69/Z) preens at the Tarentum Bridge, 28 Aug 2016 (photo by Anthony Bruno)

Hope (69/Z) preens at the Tarentum Bridge, 28 Aug 2016 (photo by Anthony Bruno)

Peripatetic: adjective [1] traveling from place to place, especially working or based in various places for relatively short periods. (definition from Google search)

Hope (69/Z, black/green) is a peripatetic peregrine falcon.  For five years she called the Tarentum Bridge her home until last spring when she nested at the Cathedral of Learning.

In my experience, peregrines stay put when they’ve claimed a prime territory but Hope does not.  On Friday she flew 15 miles back to Tarentum and set up shop for several days.

She’s so comfortable at Tarentum that, unlike her habits at Pitt, she perches in easy view.

Last weekend Tony Bruno and Steve Gosser stopped by for some great photographs. Above, Tony got a photo of Hope’s bands while she was preening.  Look how close she is!

Below, Steve caught the action when a curious mourning dove came close while Hope was eating. The dove escaped.

Peregrine falcon, Hope, confronts a mourning dove at the Tarentum Bridge, 27 Aug 2016 (photo by Steve Gosser)

Peregrine falcon, Hope, confronts a mourning dove at the Tarentum Bridge, 27 Aug 2016 (photo by Steve Gosser)

Peregrine falcon Hope stirs up a watchful mourning dove at the Tarentum Bridge, 27 Aug 2016 (photo by Steve Gosser)

Peregrine falcon Hope stirs up a watchful mourning dove at the Tarentum Bridge, 27 Aug 2016 (photo by Steve Gosser)

...and the mourning dove escapes at the Tarentum Bridge, 27 Aug 2016 (photo by Steve Gosser)

…and the mourning dove escapes at the Tarentum Bridge, 27 Aug 2016 (photo by Steve Gosser)

 

Apparently three days were long enough at Tarentum because Hope flew back to the Cathedral of Learning yesterday afternoon.  She appeared on the falconcam at 3:30pm, dug a little at the scrape and then perched and preened.

You can see her band colors below.  Her greenish right-leg band and black/green left-leg band are a diagnostic combination.

Hope reappears at Pitt, 28 Aug 2016, 3:30pm (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope reappears at Pitt, 28 Aug 2016, 3:30pm (photo from the National Aviary falconcam at Univ of Pittsburgh)

 

And here’s her familiar face.

Hope at Pitt, 28 Aug 2016, 3:34pm (photo from the National Aviary falconcam at Univ of Pittsburgh)

Hope at Pitt, 28 Aug 2016, 3:34pm (photo from the National Aviary falconcam at Univ of Pittsburgh)

 

She probably was at the Cathedral of Learning during last night’s terrific thunderstorm, but who knows.

Hope doesn’t perch in sight at Pitt so I’m never sure if this peripatetic bird is actually there.

 

(photos by Anthony Bruno, Steve Gosser and the National Aviary falconcam at Univ. of Pittsburgh)

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Aug 22 2016

Babies, It’s Hot Outside

Screenshot from Science video about zebra finch nest songs (Click on the image to see the video)

Screenshot from Science Magazine video on zebra finch nest songs (Click on the image to see the video)

Bird news from last week, in case you missed it …

Many birds talk to their eggs and there’s evidence that the eggs hear and respond.  For instance, superb fairywrens sing to their eggs and before they hatch the babies sing back!

Now scientists at Deakin University in Australia have discovered that in zebra finches what the eggs hear and how they respond is even more amazing than we knew.

In the last days of incubation, zebra finches (Taeniopygia guttata) sing a special song to their eggs but only when it’s hot outside — greater than 26 degrees C (78.8 degrees F).

The eggs hear the song and it changes their lives.

After they hatch, babies who heard the “hot call” grow more slowly than those who didn’t.  Not only are the “hot call” babies smaller as adults but they’re more successful breeders in a hot climate.  Surprisingly, this effect extends into later generations.

Small bodies cope better with heat than large ones, so signalling for a smaller size is a great adaptation for a warming climate.

But how does the zebra finch song bring about this result?

Click here to watch the video and read about this amazing feat.

 

(screenshot from Science Magazine video about zebra finch vocalization. Click on the screenshot to see the video)

One response so far

Aug 18 2016

Backyard Hawk

Red-tailed Hawk on Solomon's deck (photo by Michael Solomon)

Red-tailed Hawk on Solomon’s deck (photo by Michael Solomon)

On Throw Back Thursday:

If there’s a bulky hawk in your backyard that ignores you like this, I bet I can identify it without ever seeing it.  In western Pennsylvania, I’m 90% sure it’s a juvenile red-tailed hawk.

Young red-tailed hawks are so focused that they tune us out.  Read about this backyard bird in the 2009 article:

Single-mindedness

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Aug 14 2016

Update Your Scorecard

Magnum at the Cathedral of Learning nest, 12 August 2016, 5:15pm (photo from the National Aviary falconcam at Univ of Pittsburgh)

Magnum at the Cathedral of Learning nest, 12 August 2016, 5:15pm (photo from the National Aviary falconcam at Univ of Pittsburgh)

Get ready to update your scorecard.  There have been two! changes in female peregrine ownership at the Cathedral of Learning so far this weekend.

Friday evening “NR” saw a black/red banded female at the nest and posted a comment that Magnum was back on August 12 at 5:15pm — that’s 17:15 time code on the camera.  The photo above clearly shows Magnum’s bands.

Then Saturday night, August 13 at 6:52pm, members of Pittsburgh Falconuts saw Hope on camera calling loudly.  Terzo was nearby but he waited almost four minutes to join her.  Though her black/green bands are hard to read here, we know it’s Hope based on multiple snapshots.  She visited the nest again alone in the 8 o’clock hour.

Hope returns to the nest, 13 August 2016 at 6:52 pm (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

Hope returns to the nest, 13 August 2016 at 6:52 pm (photo from the National Aviary snapshot camera at Univ of Pittsburgh)

 

So here’s the state of play at the Cathedral of Learning pre-dawn on August 14.  I’m writing this before they wake up and change things again!

  • 30 Nov 2015: Hope arrives at the Cathedral of Learning
  • 8 April 2016 (same day):  Hope retains site after unbanded immature female visits the nest.
  • 23 April 2016 (same day): Hope retains site after a banded adult female (black/red) visits the nest.
  • 22 June 2016:  Magnum (black/red 62/H) claims the Cathedral of Learning.
  • 24 June 2016: Hope regains the site.
  • 2 August 2016: Unbanded young female claims the Cathedral of Learning.
  • 6 August 2016: Hope regains the site.
  • 12 August 2016:  Magnum (black/red 62/H) claims the Cathedral of Learning.
  • 13 August 2016: Hope regains the site.

As of this writing I have no idea where Magnum is but she knows her way around.  She’s been to the Cathedral of Learning before, possibly on April 23 and certainly on June 22.  Her home base has been the Neville Island I-79 Bridge, to which she returned after her last visit.

I don’t know how long Hope will stay this time.  Don’t even ask!

As I said on August 6, no humans ever see how these turnovers occur.  As far as I can tell no peregrines get hurt.

Thank you to NR and to all of you who check the Cathedral of Learning falconcam for peregrine activity.  Without your help we’d never know how interesting this summer has been.

 

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

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Aug 08 2016

Asleep In Flight

Published by under Bird Behavior

Great frigatebird carrying sleep monitoring equipment (photo by Bryson Voiron from Nature Communications article)

Great frigatebird with sleep monitoring equipment (photo by Bryson Voiron from Nature Communications article)

On transoceanic airplane trips the passengers try to sleep in flight but the pilots stay awake. (Thank heaven!)  Many birds, including swifts, sandpipers and songbirds, fly non-stop over the ocean for so long that scientists guessed the birds would have to sleep along the way.  But how? Wouldn’t they crash?

As part of their daily lives, great frigatebirds (Fregata minor) fly non-stop for weeks, eating flying fish and ocean-surface food in trips that can span two months and 22,000 miles.  These large birds live over the ocean but not on it because their feathers aren’t waterproof.

Great frigatebirds have got to sleep some time so researchers led by Niels C. Rattenborg of the Max Planck Institute fitted more than a dozen females with instruments to measure sleep and flight time.  The great frigatebird, above, has a sleep-measuring headset and a GPS backpack.

The results of the sleep study were surprising.

Scientists knew that, on land, birds can sleep with only half the brain while the other half stays alert for danger. They found that great frigatebirds half-sleep in the air, too, but sometimes both hemispheres sleep at once for more than two minutes.  They do it while circling on an updraft.

Another surprise was how little the birds slept, clocking only 42 minutes/day in the air compared to 12 hours/day on land.  If they were humans they’d be seriously sleep deprived.

Amazingly the frigatebirds’ performance was not affected by lack of sleep and when they got home they caught up on sleep in their first days on shore.  How many of us wish we could live like that!

Find out more here at Gizmodo or in the report here in Nature Communications.

 

(photo of great frigatebird with sleep measuring equipment by Bryson Voiron from  “Evidence that birds sleep in flight,” Nature Communications)

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Aug 05 2016

His Feathers Sing

The male club-winged manakin (Machaeropterus deliciosus) uses dance and sound to attract the ladies but he doesn’t open his mouth.  He uses his wings!

Watch and listen as he bows and flares.  The loud buzzy noise is made by his secondaries.  Cornell Lab writes:

The secondary wing feathers of the male Club-Winged Manakin, a bird from South America, are large and rigid. He strikes them together at about 107 times per second to create a buzzing sound, which is used during courtship displays.

Ornithologists have known for a long time that the males’ secondary feathers are deformed.  This 1871 drawing shows the difference between the males’ deformed and the females’ normal feathers.

Modification of Manakin Pipra deliciosa = Machaeropterus deliciosus wings for sound production, from Darwin's - The Descent of Man

Modification of Manakin Pipra deliciosa = Machaeropterus deliciosus wings for sound production, from Darwin’s – The Descent of Man

 

Now that we have high definition video we can see why they’re like that.  He makes his feathers sing.

 

p.s.  Click here for the location of secondary wing feathers.

(video from Cornell Lab of Ornithology on YouTube. Illustration from Wikimedia Commons; click on the image to see the original.)

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Jul 30 2016

Summer Pair Bonds

Dori and Louie bow at the Gulf Tower nest before dawn, 30 July 2016 (photo from the National Aviary falconcam at Gulf Tower)

Dori and Louie bow at the Gulf Tower nest before dawn, 30 July 2016 (photo from the National Aviary falconcam at Gulf Tower)

In late July, the nesting season is over but Pittsburgh’s adult peregrines still see each other every day and sometimes visit the nest to bow and cement their pair bonds.

The Downtown pair, Dori and Louie, are especially early risers.  Here they are this morning, Saturday July 30 at 5:53am.  In the distance you can see the sky lighting up in the east and the silhouette of the Cathedral of Learning.  The sun rose at 6:16am.  (They also visited before dawn on July 24.)

The Cathedral of Learning peregrines aren’t such early birds but they’re bowing too.  Sometimes Hope is impatient for Terzo to join her at the nest.  Below, she shouts, “Come here!” on 25 July at 8am.

Hope shouts, "Come here!" to Terzo, 25 July 2016 (phto from the National Aviary falconcam at Univ of Pittsburgh)

Hope shouts to Terzo, “Come here!”, 25 July 2016 (photo from the National Aviary falconcam at Univ of Pittsburgh)

Yesterday they bowed twice — at 4:11pm and 6:22pm, July 29.  Here’s their second session.

Tezro and Hope bow at the Pitt peregrine nest, 29 July 2016 (photo from the National Aviary falconcam at Univ of Pittsburgh)

Tezro and Hope bow at the Pitt peregrine nest, 29 July 2016 (photo from the National Aviary falconcam at Univ of Pittsburgh)

Now that the “kids” have grown and flown, the adults spend time with each other.

 

(photo from the National Aviary falconcam at the Gulf Tower)

10 responses so far

Jul 29 2016

Urban Birds Have It All

Peregrine falcon, Dorothy, at the Cathedral of Learning, Feb 2011 (photo by Patricia Szczepanski)

Peregrine falcon, Dorothy, at the Cathedral of Learning in February 2011 (photo by Patricia Szczepanski)

Twenty-five years ago peregrine falcons moved into the City of Pittsburgh.  Since then lots of cool raptors have come here, too, including red-tailed hawks, Coopers hawks, turkey vultures and, most recently, bald eagles.

City living provides food and protection from predators but birds face new challenges by living near humans.  Jean-Nicolas Audet of McGill University wondered if these challenges put city birds at a disadvantage compared to their country cousins so he designed some tests to answer these questions:  Which group is better at problem solving? Which group is more immune to disease?  And since both traits require lots of energy, is there a trade-off such that smarter birds have lower immunity?

The Caribbean island of Barbados has both city and country habitats and an endemic species that lives in both places, the Barbados bullfinch (Loxigilla barbadensis).  Audet tested the bullfinches and the results were surprising.

“We found that not only were birds from urbanized areas better at innovative problem-solving tasks than bullfinches from rural environments, but that surprisingly urban birds also had a better immunity than rural birds,” says Jean-Nicolas Audet, a Ph.D student in the Department of Biology and first author of the study published in the journal Behavioral Ecology in 2016.

As earth’s human population grows and more habitat is converted to cities, more birds may have to choose the urban environment.  If they can adapt, it will be a smart move.  As Audet says, “Urban birds have it all.”

 

Read more about the 2016 study and find links here to The town bird and the country bird: problem solving and immunocompetence vary with urbanization.

(photo of Dorothy in 2011 by Patricia Szczepanski. video from McGill University on YouTube)

2 responses so far

Jul 28 2016

Drinking Techniques

Italian Sparrows in Bolzano, Italy (photo from Wikimedia Commons)

Sparrows take a sip in Bolzano, Italy (photo from Wikimedia Commons)

On Throw Back Thursday:

Like us birds drink more water in the summer heat.  Have you noticed they use different drinking techniques?  Some drink with faces down, others tilt their faces up.

These house sparrows appear to be using the face-down technique on a martini.  But wait!  The glass held ice cream and they’re picking at the remains.   So what do they really do?

Find out how birds drink in this vintage article from 2010:

Anatomy: How Birds Drink

 

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

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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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