Archive for January, 2008

Jan 31 2008

Life Birds

Ross's Geese in Allegheny County (photo by Geoff Malosh)I keep a list of the birds I’ve seen but I’m not particularly driven by it.  Last Sunday I found out how little I consult my list when I saw a life bird and didn’t realize it at first. 

If I’d known that I’d never seen them before, I would have made a bigger effort to find the Ross’s geese who’ve been visiting Allegheny County since early January.  Here they are, photographed by Geoff Malosh.

After these unusual geese spent two weeks in the North Hills, Dan Yagusic reported them roosting at Six Mile Island in the Allegheny River near Sharpsburg.  They’d made it to my home zone so I went to see them. 

Ross’s geese are very beautiful – like small snow geese with stubby bills and rounded heads.  They are unusual in Pennsylvania because they nest in the arctic – primarily at Queen Maud Gulf Migratory Bird Sanctuary – and migrate to California’s Central Valley and, to a lesser extent, to Arkansas, Louisiana, New Mexico, Texas, and Mexico.

Our three geese are probably a family group who strayed too far east.  Fortunately, they found a large flock of Canada geese who know where to roost and feed so they’ve stayed safe by hanging out with them.

Compared to other geese that nest in the same arctic region, Ross’s geese are the last to arrive at the spring nesting grounds and the last to leave in the fall.  If our weather holds, we may have these special geese in Pittsburgh for a while longer.
 

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Jan 29 2008

Spring is in the air

Peregrine falcon visits her nestbox at University of Pittsburgh, 28-Jan-2008After two days of dreary overcast skies the sun came out on Monday and so did the birds!  It was an exceptionally good day for watching peregrines at the University of Pittsburgh.

I could tell the day was full of promise as I walked to work through Schenley Park.  Cardinals were singing and a peregrine was perched on the lightning rod at the Cathedral of Learning.

My friend Karen Lang called to say she saw both falcons at the building – the first time in weeks we’d seen more than one.

I checked the National Aviary’s webcam from my desk.  Woo hoo!  Footprints in the snow.  It could only have been a peregrine.  They won’t let any other bird near their nest.

And then I remembered the webcam has a motion detection feature.  Did it capture Dorothy’s visit to the nest?  Yes!  Here she is arriving at the perch.

She stayed only two minutes but she made my day.  Spring is in the air.

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Jan 28 2008

Counting Crows

Crow roost at dawn (photo by Doug Bauman) Last Friday outside my office window I noticed a steady stream of crows flying west-northwest into Oakland.  They were coming in to roost.

I went back to the task at my desk but when I looked up again the stream was still there, still steady.  Amazing.

I usually don’t try counting crows because I lose track but I remembered Dr. Tony Bledsoe telling me how he estimates flock numbers by counting the rate of birds during a given period of time, then measuring the time.

I picked a point of reference and set my stopwatch.  200 crows per minute.  Now all I had to do was watch until the stream ended and check the rate of crows periodically. 

I watched until it was too dark to see them.  I checked the rate a couple of times and they still flew in at 200 crows per minute.  Even after dark they kept coming, though the rate seemed to drop, but at that point I couldn’t be sure because they matched the sky.

From start to end, it was 70 minutes.  14,000 crows.  And those were only the crows I could see!  Judging by reports of crows elsewhere in Pittsburgh, the total number could be two or three times that.

In about a month, the flock will begin to disperse.  In the past few weeks they’ve changed their start and end points, and anyone who thinks “as the crows flies” means a straight line ought to watch this flock.  Even their flight path curves in the sky.

What a spectacle!  I’ve been to Nebraska to see sandhill crane migration and to Middle Creek to see snow geese.  Crows aren’t as “nice” as cranes and geese but they put on just as big a show.

           The photo is a Pittsburgh crow roost at dawn by Doug Bauman.

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Jan 27 2008

BIRD The Definitive Visual Guide

Published by under Books & Events

Book: Bird The Definitive Visual GuideWhen the weather is cold and miserable I stay indoors and read more.  In winter I am especially drawn to beautiful bird books because I want to see birds, not just read about them. 

This winter I can’t say enough about a beautiful book I got last month:  BIRD The Definitive Visual Guide, Audubon, DK Publishing, 2007.

It’s a gorgeous book, full of photos illustrating bird anatomy, bird habitat and over 1,400 species from around the world. 

Every page is beautifully done.  The layout is gorgeous and the contents are a fireside birders dream with informative species accounts, range maps, species size, habitat and migration.  And it includes a CD of 60 species’ songs and calls. 

I open BIRD at random for the “wow effect” and am never disappointed. 

It’s even beautiful when it’s closed.  The margins are printed with flock, jungle and feather patterns so the edges look marbled.

If you’re looking for something to do indoors, take a look at this book.

Read another review on the BirdFreak blog.  If you want to buy it, I suggest Amazon where the price is discounted. 

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Jan 25 2008

Flock Patterns

American Robin flock (photo by Tom Pawlesh)Starling flock (photo by Tom Pawlesh)Double-crested Cormorant flock (photo by Chuck Tague)Tundra Swans flock (photo by Chuck Tague)

Outside my office window in the afternoon, I see flocks of crows, robins and starlings heading for the roost.  Lately it occurred to me that I’m able to identify them at a glance, not by looking at the individual birds but by looking at the shape of the flock.  This skill was particularly useful at the robin roost on January 6 because it was too dark to see individual birds.  

As you can see in the pictures above, the flock shapes can be different even in birds of the same size.  From left to right are four flocks:  American robins, European starlings, double-crested cormorants and tundra swans.  (First two photos are by Tom Pawlesh, last two by Chuck Tague.)

Here are some flock shapes I can think of: 

  • American robins: loose flock, widely spaced.  Each bird maintains the same relative position within the flock.
  • Starlings and pigeons: tight flock, synchronicity. Every bird makes the same move at the same time.
  • Double-crested cormorants:  J-shaped flock or a long line.  The flock looks scraggly.
  • Geese and swans:  V, J or crescent-shaped flock.
  • American crows:  A loose flock in which each bird has his own idea about where he wants to be.  Individuals show considerable positional movement within the flock.  The birds look like black rags flapping in the sky.
  • Blue jays:  A loose flock so widely spaced that they sometimes look like they’re not traveling together.  Individuals maintain the same relative position within the flock.
  • Cedar waxwings and American goldfinches:   The flock moves in unison but individual birds change position within the flock, mostly by moving up or down.  American goldfinches say “potato chip” as they fly.
  • Small finches, common redpolls:  Fly fast in relatively tight flocks.  The flock moves in unison.  Individuals zip forward or slow down but maintain positional integrity. 
  • Cowbirds: have a cool hopscotch pattern as they sweep across a field searching for food.  (comment from Chuck Tague)
  • Brown pelicans: The flock travels in a long line, skimming the surface of the ocean.  They will even skim the surface of high rise buildings at the beach.  Each bird synchronizes wing movement with the flock:  first bird flaps downward, then second bird, then third, then fourth…
  • On water American coots huddle close together in an extremely dense flock in the presence of a bald eagle.
  • Turkey vultures:  Soaring birds.  Each bird goes his own way but they stay together.  They hate to flap.
  • Cranes: Soaring birds who travel in flocks, sometimes in a loose V.
  • Hawks and falcons:  no flock at all.

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Jan 24 2008

No, they won’t eat corn

Immature Coopers Hawk (photo by Chuck Tague)An animal-lover friend of mine began to feed the birds and was shocked when a coopers hawk killed a mourning dove at her feeder.  She does not eat meat and wanted to know if she could train the coopers not to eat meat either.  “If I put out more corn, will he eat the corn and not the doves?”

“No,” I said, “he will not eat corn.  He’s a carnivore.  That’s just how it is.”

Because humans are omnivores and we grow our own food, we find it hard to imagine the lives of creatures who must hunt to live.  If a coopers hawk is not an efficient hunter, if it does not kill birds, it will die.  It would be cruel to the hawk if it could not hunt. 

But what about the prey species?  Is it cruel to them that they are hunted? 

There is a beautiful poem by James Dickey in which he describes the heaven where wild animals go.  Called The Heaven of Animals he describes the predators in their heaven crouched on the limbs of trees and writes,

“And those that are hunted
Know this as their life,
Their reward: to walk

Under such trees in full knowledge
Of what is in glory above them,
And to feel no fear,
But acceptance, compliance.”

The universe is structured so that everything is eaten by something – in the grave, if not before. What an amazing cycle.

That’s just how it is.

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Jan 23 2008

Irruption!

Published by under Migration

Common Redpolls at Bushy Run feeder (photo by Mark McConaughy)Not “eruption,” which is a violent bursting out, but “irruption” which is a bursting in, an invasion. 

This winter is an irruption year for birds.  Three of the invaders are pictured here by Mark McConaughy at Bushy Run Battlefield’s feeders.  They are common redpolls, a very small finch with a red cap and black chin who normally lives in the boreal forest and taiga of Canada and Alaska.  (The male has a rosy chest.)

Last Sunday I went to Bushy Run to see these tiny invaders because I hadn’t seen them for 10 years – not since the irruption of 1997-1998.  That’s how infrequently they come this far south.

Why do they stay north most years but visit us occasionally in winter?  Ron Pittaway of Ontario Field Ornithologists monitors food supplies in the northern forest and makes a winter finch prediction every year.  This year the tree seed crops of birch, alder, spruce and fir are all quite low.  The winter finches would find little to eat in Ontario.  He predicted an irruption.

Redpolls, who thrive on birch and alder seeds, are not the only species to invade southwestern Pennsylvania this winter.  Others include:

  • Evening grosbeaks, a large yellow seed-eating finch with a very large beak (‘gros’ means large in French).  Evening grosbeaks used to be abundant but are declining because their summer food, the spruce budworm, has declined in recent decades. 
  • Pine siskins, a small, brown, striped finch with a yellow splash on his wings and tail.  Pine siskins eat spruce and fir seeds in winter.  They also visit feeders.
  • Northern shrikes, a predatory songbird who eats birds, insects and small mammals.  The shrike doesn’t have sharp claws so he must impale his prey on spikes or barbed wire to eat it.  This bird came south because his prey did. 

I saw a northern shrike in November at Moraine State Park and redpolls last Sunday.  I’m still hoping to see evening grosbeaks and pine siskins before the irruption ends.  I almost want winter to last a little longer so I have more time.  Can you believe it!

(photo by Mark McConaughy)

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Jan 21 2008

Coping with Cold: Anatomy

Canada Geese come in for a landing (photo by Chuck Tague)

What a cold night!  Temperatures in the single digits!  Again I thought of how the birds are coping with cold. 

Chuck Tague’s beautiful picture of Canada geese made me wonder how they can swim in near freezing river water and stand on ice for hours.  It turns out that birds have special adaptions to keep themselves warm.

Feathers are one big advantage.  Not only do they naturally conserve heat but the feathers closest to a bird’s skin are downy.  Birds fluff their feathers to expand the down when the weather’s cold, making the little birds look like butterballs.

You can see the effect of feather insulation at this link showing infrared photos of a parrot on a person’s arm.  The person’s arm looks “hot” but the parrot’s body looks “cool” because its feathers are such good insulation.

Another cold weather advantage for ducks and geese are their waterproof feathers and a layer of fat under their skin.  The fat keeps them warm in cold water and their feathers keep them dry.

This leaves the problem of warming their feet.  Birds can tuck a foot up under their feathers but this is impractical for very long.

So how can geese stand on ice in their bare feet?  Water birds have an unusual circulatory system in their legs and feet.  The veins and arteries in their legs are intertwined so that cold blood leaving their feet is warmed by the arteries delivering warm blood.  (Open the comments below for a more accurate explanation from Dr. Bledsoe of Univ of Pittsburgh.) 

Perhaps this means birds’ feet are a little colder all the time, but it doesn’t bother them.  The advantage is that their central body doesn’t have to cope with cold blood returning directly to their hearts.

We humans don’t have these advantages so my feet are mighty glad they’re indoors right now.

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Jan 19 2008

Hidden in Plain Sight

Published by under Peregrines

Peregrine falcon at McKees Rocks (photo by Joe Fedor, Jr.)Sometimes a change goes unnoticed because we don’t expect to see it.  Our brains explain it away because it doesn’t fit.

I believe that’s what’s happened with a pair of peregrine falcons at the Ohio River near Brunots Island.  Peregrines have been rare for so long that we can’t help but think a falcon more than four miles from the nearest peregrine nest must be that nesting bird.

The first PABIRDS report of peregrines near Brunots Island was made in January 2004 by Dave Wilton.  Reports continued over the years, including one from Scott Gregg in May 2006 and another from Sam Sinderson in May 2007, when all the area’s peregrines had nestlings miles away. 

Then last month Mark Vass reported two peregrines chasing a red-tailed hawk away from the area.  Dan Yagusic, who discovered the Bridge Birds at the Allegheny, nudged me into thinking about Mark’s sighting.  To him it was exactly the sort of thing he’d seen for three years at the Allegheny River before he made the connection that peregrines were nesting there.

I decided to put a request on PABIRDS asking if anyone in the Brunots Island area was up for watching peregrines.  Joe Fedor Jr. responded.

Joe works near the site and began looking for peregrines and photographing them when they were close enough.  Soon he had a picture of a pair perched on a nearby electric tower.  Then, using his scope, he took the picture shown above. 

Aha!  A peregrine hidden in plain sight.   Maybe this spring Joe will find a nest.  I hope so!

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Jan 17 2008

Red Fox, Fox Squirrel

Published by under Mammals

Red Fox (photo by Chuck Tague)Not a bird story, but interesting anyway. 

Last Saturday my husband and I visited Homewood Cemetery in Pittsburgh’s east end and walked around the part of the cemetery that borders Frick Park.  I came around the edge of a building – a mausoleum, actually – and suddenly saw a red fox carrying a dead fox squirrel in his mouth.   Fox squirrels are larger than gray squirrels and have fox-colored reddish coats.

I called softly to my husband to come see the fox but it heard my voice and immediately disappeared into Frick Park’s brush and trees.

After I posted my sighting on PABIRDS, Candy Gonzalez from Lawrence County replied that squirrels seem to make up a large part of the fox’s diet.  As she wrote, “Once they are seen in a residential neighborhood, it seems they stay for a year or two until there are virtually no squirrels left. …  They seem to raise a couple litters, feed them with the squirrels, and then move on to someone else’s neighborhood.”

Nature’s way of balancing the number of squirrels at our bird feeders.

(This photo by Chuck Tague is not the fox I saw.)

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