Archive for January, 2011

Jan 21 2011

Wearing Black-n-Gold!


Did I tell you I live in Pittsburgh where the Steelers are playing the AFC Championship game against the New York Jets this Sunday? 

It’s a rare day that bird anatomy is related to the Steelers, but today is that day.  Here’s how it happened. 

For many weeks I’ve been using Frank B. Gill’s Ornithology to inspire Friday’s anatomy lesson.  Rather than read the whole book I open the index at random and with my eyes closed I point to a word.  Then I look up that word and find something interesting to write about.  Today’s word was “Yellow-throated Brush Finch, page 328.”

Page 328 discusses the advantages of multispecies flocking.  Many species form mixed flocks because they get more to eat when there are many eyes watching for danger.  In Pennsylvania we often see mixed flocks in winter led by titmice and chickadees.  The leader species are dominant, the other species are subordinate.

Some birds go one step further.  Ornithology describes how in some mixed flocks “unrelated bird species have similar plumage color patterns that promote flock cohesion.  Subordinate species increase acceptance by resembling dominant flock members.” 

These distinctive color patterns are called flock “badges.”

The yellow-throated brush finch (bottom right) is a member of one of these unusual flocks in Western Panama.  His compatriots are all yellow and black.

As I assembled this photo, I suddenly realized that the brush finch and all his friends are wearing Steelers colors.  It’s a whole flock of black-n-gold birds!  How cool is that?! 

So this is what we look like in Pittsburgh right now.

We’re wearing Black-n-Gold.  We’ve got our Flock Badges on!

.

(composite photo credits, top left to right, then bottom left to right:
1. Slate-throated Whitestart: Corey Finger on 10000birds.com
2. Sooty-capped Bush Tanager: Wikipedia
3. Yellow-thighed Finch: Wikimedia Commons
4. Collared Whitestart: Jan Axel on janbirdingblog.blogspot.com
5. Silver-throated Tanager: Kent Fiala’s Website
6. Yellow-throated Brush Finch: Atrevido1 at Solo Aves on Flickr
)

16 responses so far

Jan 20 2011

You’re Invited on March 7!

Peregrine fans!  I’ve planned this event just for you.

Gear up for peregrine season on Monday March 7, 2011, 6:00-8:00pm at WQED in Oakland, 4802 Fifth Avenue, Pittsburgh, PA 15213.

Join me to Celebrate Pittsburgh’s Peregrines!

We’ve met each other on the blog and corresponded online.  Here’s a chance to meet face to face, learn about peregrines, and share our enthusiam for these charismatic birds.

I’ll present the life and history of Pittsburgh’s peregrines.  Steve Sarro and Cathy Schlott, from the National Aviary, will join us with a special avian guest.

Light refreshments will be provided.

This event is free, but space is limited!

Reservations are required so call WQED at 412-622-1505 or email peregrines@wqed.org to reserve your space now.

Come learn about peregrines on this special evening devoted to our beloved birds. 

I’m looking forward to meeting you!

Note:  This event is geared toward adults (with wine and Powerpoint). Sorry, we cannot accommodate children under six years old.

(photo by Kim Steininger)

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Jan 19 2011

Winter Weeds: Staghorn Sumac


Though this plant is not a “weed” I decided to include it in the Winter Weed series because it’s such an important food for birds.

Staghorn sumac is a shrub-like tree in the Cashew family that often forms thickets.  In autumn it drops its large compound leaves to reveal stout, densely fuzzy twigs with dark red fruit clusters at their tips.

The clusters are shaped like candle flames and, like flames, they point upward.  The fruits are small reddish berries about the size of peppercorns studding the structure.  Birds perch on the clusters and pull off the fruits, as this downy woodpecker is doing.  Even when most of the fruits are gone the “candle flame” structures persist through the winter.

Though birds like the fruit they ignore staghorn sumac in fall and early winter, just as they ignore crabapples, because they aren’t palatable yet.  This winter the crabapples were ready to eat first.  Freezing weather in December softened the crabapples so that by early January the starlings and robins mobbed the trees and left a mess on the sidewalk.

They still ignored the sumac until last weekend.  On Sunday I found a flock of robins feasting on staghorn sumac in Schenley Park.  Some of the berries sprinkled the snow with tiny red dots.

When I found the dots I looked up.  What a good clue for finding birds!

(photo by Marcy Cunkelman)

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Jan 18 2011

Close-up at Tarentum

Published by under Peregrines

 
Last Sunday afternoon, Steve Gosser stopped at the Tarentum Bridge to see if he could find one of the peregrines that have been there for over a year. 

He was lucky!  When he arrived two birders pointed out a peregrine in a tree by the river, almost at eye level.  The bird waited patiently while Steve took nearly 50 pictures. 

And here she is. 

This is the same female peregrine who nested at the Tarentum Bridge last year.  Hatched at the Benjamin Harrison Bridge near Hopewell, Virginia in 2008, she was hacked (first flight) at Shenandoah National Park.  Last year her mate’s bands indicated he hatched at the Cathedral of Learning nest in 2008, son of Dorothy and E2.  

This pair was very active at the bridge last spring.  They were even seen mating, but no one knows where she laid her eggs because her nest never produced young.

Fortunately that experience didn’t stop her.  It’s obvious she considers Tarentum her home. 

I hope she picks a suitable site for her eggs this year.  It would be great to watch her babies fly.

(photo by Steve Gosser)

p.s.  If you didn’t see my peregrine news last Saturday, scroll down to the January 15th entry.

13 responses so far

Jan 17 2011

Birds of the Gods


Coming this Sunday January 23 at 8:00pm on PBS’s Nature is a fascinating program you won’t want to miss:  Birds of the Gods.

Narrated by David Attenborough, the show travels with Indonesian ornithologists to the remotest parts of New Guinea to film stunning birds-of-paradise.

New Guinea is a huge, mountainous, jungle-covered island north of Australia that had no mammalian predators until humans arrived.  When they did, they were fascinated by these flashy birds whose courtship dances became part of human culture and whose feathers became essential symbols of status and wealth. 

In Indonesian villages the feathers adorn elaborate headdresses and are used like money.  Because the feathers are valuable the villagers protect their birds until needed for ornamentation.  Unfortunately New Guinea’s habitat is changing.  The program shows how local scientists are helping villagers preserve the headdresses with mothballs, allowing more birds to live. 

Why are the feathers so valuable? 

Birds-of-paradise are an excellent example of runaway selection.  The drab females of these 40 species select mates who are “fashion icons.”  All the males have elaborate feathers and amazing dance repertoires, but only the fanciest plumes and the best dance steps win a mate.  The females watch intently, stepping in for a closer look.  After thousands of generations only the most beautiful dancing males catch the females’ attention to reproduce. 

To give you an idea of their beauty, shown above is a male Greater Bird of Paradise in courtship display.  You can see his beautiful ruby tail and wings and his astonishing yellow-and-white upper tail coverts.  This is only his back end!  His chest is iridescent green.

But to really understand these birds you have to see them dance.  The program has awesome video footage of courtship displays.  My favorite is the ultimate fashion icon, the Superb Bird of Paradise.  You have to see him to believe him!

Watch Birds of the Gods this Sunday, January 23 at 8:00pm EST on PBS.  This news just in!  Check your local listings!  The show isn’t running on all stations.

In Pittsburgh, it’s on WQED.

(photo of a Greater Bird of Paradise in courtship display, by Andrea Lawardi via Wikimedia Commons.  Click on the photo to see the original)

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Jan 16 2011

Dreaming of Birds

Published by under Beyond Bounds


We’ll never see this combination in Pennsylvania:  a roseate spoonbill gazing at a marbled godwit.

Sigh. 

I’m dreaming of birds who live where it’s warm. 

(photo by Steve Gosser)

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Jan 15 2011

Webcams and a Warning

Published by under Peregrines


On Thursday morning just after dawn, six hardy souls brought gear and expertise to the top of the Cathedral of Learning to fix the peregrine webcams. 

It was 18oF and snowing and the job required a visit to the ledge.  Would it be too dangerous?  Would we have to cancel?

We hoped not.  Both cameras were dead and we had to fix them very soon because the resident peregrines, Dorothy and E2, have become increasingly territorial and ready to defend their nest. 

Fortunately, the camera that streams to WildEarth needed mostly indoor effort.  Bill Powers of PixController installed new equipment to generate the streaming images.  As soon as he hooked it up, a coworker tested it remotely.  Success!   All that remained was to clean the camera cover and adjust the infrared array for nighttime viewing.

The snapshot camera was another story.  It refused to communicate with the Internet so the only way to fix it was to bring it indoors.  Braving snow and a possible peregrine attack, Dave Marti of Pitt’s Facilities Management took the snapcam (pictured above) off the wall and brought it in.  Dorothy and E2 flew by but they didn’t stop.  E2 was carrying breakfast for Dorothy; they had food on their minds.

Indoors with the snapcam I realized I had to perform surgery to fix it.  Thanks to Chris Gauss’ and Steve Sarro’s assistance, we successfully replaced the Ethernet cable and reassembled the camera.  Whew!  It was ready to go outdoors.

Back on the ledge, Dave finished the work on both cameras while Chris Gaus and Tony Bledsoe waved brooms to warn the peregrines away.  By this time Dorothy was curious and a little annoyed.   She strafed the ledge but didn’t attack.  The guys finished up quickly and came inside. 

As soon as they were gone Dorothy perched by the snapcam.  “I’m warning you!  This is mine!  Go away!”

The cameras will soon be visible on the Aviary website.  Watch here for news.  Meanwhile, click on the imbedded links to see more pictures of our adventure from Bill Powers.  (And here’s what the snapcam saw while it was being reinstalled.)

(photos by Bill Powers, PixController.com)

5 responses so far

Jan 14 2011

Dominance


I usually reserve Friday’s blog for an anatomy lesson but today’s topic on bird behavior does have anatomy in it.  Dominance among birds, as among humans, is expressed in both behavior and outward appearance.

If you’ve watched birds at your feeder for any length of time you know some birds are dominant over others, not only between species (blue jays rule!) but among the same species (some cardinals are bossier than others).

The dominant birds tend to be physically larger than their subordinates and sometimes they’re marked differently.  This is especially true of male house sparrows who wear their status on their chests. 

Among researchers, the bib on a house sparrow is called a “badge of status” because it’s a clear outward sign of dominance.  All house sparrow bibs become fainter in winter but at any given time of year the bigger and darker the bib, the more dominant the bird.  In a contest between the two birds pictured above, the one on the left wouldn’t even attempt to challenge the one on the right.  Mr. Big Bib wins, just by showing his chest.

Because they’re unevenly matched, these two are unlikely to fight at all.  However, males with similar badge size fight more often between themselves perhaps because it’s not obvious who’s in charge.  Eventually the contests work themselves out and everyone knows his place.

Jays can avoid contests altogether by figuring out the hierarchy from afar.  Here’s a hypothetical story showing how they do it:

Two jays, Charlie and Bob, are in the same flock where Charlie knows he’s subordinate to Bob.  One day Arnold shows up.  From a distance Charlie can see that Bob is subordinate to Arnold so Charlie knows, even before he meets Arnold, that Arnold is dominant over him.  This saves a lot of trouble in the long run!

It sounds almost human.  ;)

(photos from Wikimedia Commons)

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Jan 13 2011

Whoa there!

Published by under Bird Behavior


Last weekend the birds were hopping all over Marcy Cunkelman’s yard in the snow. 

You can see a male cardinal and a dark-eyed junco, both airborne. 

And waaaayyy over on the left a female cardinal has raised one wing like a stop sign.  Is this too much excitement for her?

“Whoa there!”

(photo by Marcy Cunkelman)

6 responses so far

Jan 12 2011

Winter Weeds: Broom Sedge

Published by under Winter Weeds & Trees


I’m sure you’ve seen this copper-colored grass before.  It’s a distinctive plant in winter fields but unremarkable the rest of the year. 

Broom sedge (Adropogon virginicus) is a native, perennial, warm season grass that’s half misnamed.  It’s not a sedge — it’s a bluestem grass — but early settlers did use its winter stems to make brooms. 

The stems stand two to four feet tall in clumps in overgrazed fields and poor soil.  You’ll find them easily in open areas where they remain standing throughout the winter, even in livestock fields, because the mature plant is too tough for cattle and wildlife to eat. 

Broom sedge is one of the first plants to grow in bare earth and can invade an area and maintain its grip because it produces chemicals that suppress the growth of competing species.  Thankfully, it doesn’t do well in fertile soil and is crowded out by “better” plants in less than ten years. 

Look closely at its stems and you’ll see its hairy seeds that disperse in the wind. These seeds are food for small birds and rodents who also find the clumps a convenient shelter.  That’s why you’re likely to see a raptor hunting the fields where broom sedge grows thickly.

So now you know a secret to impress your friends:  When you see broom sedge growing, you know the soil is poor. 

(photo by Dianne Machesney)

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