Outside My Window

On December 26th I wrote about a pair of peregrine falcons who’ve chosen to nest on a bridge over the Allegheny River.  Last year their eggs did not hatch but they still claim the site as their territory.  Last week they got a boost toward a successful breeding season with a nestbox provided by the Pennsylvania Game Commission.

Why would people make a nest for peregrines? 

Peregrine falcons don’t use sticks to build their nests.  In the mountains and at the sea they choose a high, sheer cliff where they look for a narrow, gravelly ledge and dig a depression called a scrape.  The scrape provides drainage, keeps the eggs from rolling off the cliff, and creates a rim to support the mother bird so she doesn’t crush the eggs during incubation.

The female peregrine at this bridge probably chose it instead of a cliff because this part of Pennsylvania doesn’t have high, sheer rock faces.  And it probably reminded her of home.  She was born on a bridge in Virginia.

In any case, there was no gravel last spring so she laid her eggs on a steel beam.  She probably coudn’t keep the eggs warm, they may have cracked and then the area flooded.  No baby falcons last year.

Peregrines falcons are still endangered in Pennsylvania so the Game Commission visited the site and saw that our lady had tried and failed.  They decided she was there to stay and would benefit from a nest box anchored to the underside of the bridge. 

As you can see from this picture, she now has a beautiful box, deep gravel and a hood to keep the rain off.  We hope she likes it.  If she does, we expect to watch baby falcons take off from their river home.  Fingers crossed!

Many thanks to Beth Fife and Doug Dunkerley of the PA Game Commission who installed the nest box.  Thanks to Doug for providing the photo.

In the evening the crows now flock to Oakland and roost around WQED.  Everyone notices them and asks me what the crows are doing. 

Expert answers, by Dr. Kevin J. McGowan of Cornell University, can be found here.  Please do click on the link and read about it.  It’s fascinating!

My answers - totally non-expert - are best expressed by my favorite poem that describes what these entertaining black birds are up to: 

Crows  by Doug Anderson, from Blues for Unemployed Secret Police Curbstone Press ©2000.  Reprinted by permission, http://www.curbstone.org/.

Crows

Hunch in the trees
to gossip
about God and his inexorable
experimenting,
about deer guts and fish so stupid
you could sell them air
and how out in the deserts
there’s a dog called coyote
with their mind
but no wings.
Crow with Iroquois hair.
Crow with a wisecrack
for everybody,
Crow with his beak
thrust through a bun,
the paper still clinging.
Then one says something
and they all leave,
complaining
the trees are not
what they used to be.
Crow with oilslick eyes.
Crow with a knife
sheathed in a shark’s fin.
Crow
in a midnight blue suit
standing in front of a judge:
Your Honor, I didn’t
kill him,
just ate him
and I wasn’t impressed.
Crows
clustered in the bruise light
in the bottoms
of dreams.
Crows in the red maple.
Crows keeping disrespect
respectable.
Crows teasing a stalking cat,
lifting off at the last minute,
snow shagging down
from their wings.
Crows darkening the sky,
making fun of the geese
on their way to Florida.
Crows in the roses,
beaks and thorns.
Crows feeding lizards
to their brood.
Crows lifting off road kill,
floating back down
after the car has passed.
Crow with a possum eye
speared on its beak.
Crow with a French fry.
Crows
in the chicken cages
on their way to market,
the farmer finally gone mad.
Crows hunkered down
rumpling feathers,
announcing the cataract
of snow
over the sun.
The crows prosper.
Carrion is everywhere.
The night
that is coming
is so dark
it will feel
like fur on the eyes.
So dark suddenly
you cannot see the snow.
Thrust your hand in it.
Hear it like sand
blowing on the roof.
A crow shifts his foot
and snow sifts
down from the tree.

(The picture is a stock photo of a raven.)

Well, to be exact, there’s a sandhill crane at Ethel Springs reservoir between the village of Peanut and the town of Derry.  (The reservoir is also called Derry Lake.)

Sandhill Cranes are unusual in Pennsylvania and unheard of in the Laurel Mountains so it was quite surprising when this one showed up last month. 

Most sandhills breed in Canada and the western U.S., then migrate to Texas, northern Mexico and Florida for the winter.  They usually travel in flocks and family groups but this one is alone and far off its migratory path.  Cranes feed and breed in open marshes and wet grasslands.  Perhaps the lake was this bird’s last best choice when it saw the mountains up ahead. 

The crane survived our early January cold snap by hanging out with the resident mute swans and mallards.  I suspect some kind-hearted folks made sure it had something to eat.  People walk and jog on the lake path yet the crane is as unconcerned by humans as the ducks are. 

Cranes are huge birds - four feet tall - and unmistakable.  People sometimes confuse them with great-blue herons so that may be why this one is not stirring up a lot of attention. Birders, however, are pretty psyched.  Tim Vechter has been watching the crane for a few weeks and provided these photos. 

I hope the sandhill crane enjoys its stay and makes it safely home to Canada in spring.  It will certainly have quite a story to tell when it gets there.

As I write there’s a tremendous racket going on in my neighbor’s back yard. The blue jays are screaming and jumping around in the spruces, focused on a spot I cannot see.  Starlings are loafing nearby to see what happens.  Twelve nervous mourning doves are sitting in the black locust.  The juncoes have joined the fray in the spruces, even though they’re normally wary of jays. 

Everyone’s excited about a predator in the spruces.  I can only guess it’s an eastern screech-owl.

Blue jays are an excellent alarm system.  I often use their calls to find birds of prey.  Small birds are saved the surprise of being eaten when they hear the jays’ alarms.  Even though the rest of us benefit from them, the jays just view it as doing their part to make the world safe for blue jays.

At rush hour last night, a river of crows flew over Fifth Avenue and perched in the trees on Wilkins.  That event and last week’s robin roost prompted me to think about flocking behavior. 

We’ve all noticed that birds flock in winter.  It turns out that flocking is usually a trait of social species, such as crows and parrots, and species whose food sources are abundant: omnivores like gulls and starlings, seed-eaters like blackbirds and finches.  But why to they do it?

The first reason is defense.  It’s harder to be caught unawares if you’re in a flock with many watchers and it’s statistically quite safe.  At the robin roost we heard a pair of great-horned owls but each owl will catch only one bird per night, leaving an individual robin with a 0.002% chance of becoming an owl meal.

Another flock advantage are the many eyes searching for food.  If the food source is abundant - a seed field or a landfill - everyone gets a meal.  Obviously, flocking doesn’t work for birds like red-tailed hawks who catch their prey by stealth. 

Social species enjoy flocks.  Crows get smarter by being with each other.  As Candace Savage said in Crows: Encounters with the Wise Guys:  “Nothing is more intellectually challenging than living in a social group, surrounded by a bunch of other animals that are sharpening their wits on you.” 

The most spectacular flocks are made up of starlings who wheel in unison without an apparent leader.  Tom Pawlesh took this photo of a spectacular “cloud” of starlings.  Not all birds fly in a tight formation like this.  When it comes to flocking, starlings are the champs.

For the past two days it has been “unseasonably warm” here in Pittsburgh, but to me it feels unnatural.  The highs have been in the upper 60s, warmer than we keep our house at this time of year.  This is even more remarkable because it was 13^oF five days ago.

The weather reminds me of a comment made by a young Finnish friend of ours who visited Pittsburgh in July many years ago.  As we sat outdoors after dark watching a softball game under floodlights, Oüti said she had never been outdoors when it was both hot and dark.  The sun hardly sets in the summer in Finland so being warm after sunset was unusual for her. 

Well, this weather feels the same way.  The sun set just after 5:00pm today but it feels like the end of March.  By that measure, the sun should have set after 7:30pm and it would not have been both hot and dark during rush hour when I took this picture in Schenley Park.

I do appreciate that it feels good to stroll outside and that the birds sing in the morning.  It just unsettles me a little.

News of the huge robin roost first came from Scott Kinsey when he asked for help counting them.  ”To anyone who thinks robins flew south for the winter, take a look at this.  I hope to figure out how many thousands are at this roost.” 

Dave Wilton helped him count 25,000 but they didn’t have a good vantage point.

At dawn a few days later in a wooded valley, Dave Wilton witnessed a “100,000 bird explosion… in what can only be described as a nuclear detonation of birds roaring into the sky.”  He had found the roost.

That evening Geoff Malosh watched “how utterly spectacular this robin roost in Allegheny County really is.  …I am not at all uncomfortable in guessing that there are actually six digits worth of robins. …It really is an incredible sight.”

Birders flocked.  I was there for both sunrise and sunset today.

In the dark before dawn, the robins called softly to each other but there was no activity… yet.  About 1/2 hour before dawn they began to fly up, not by skimming the treetops but by shooting straight into the sky.  They were not in tight flocks.  They were everywhere.  By dawn the whole sky was thickly peppered with robins flying in every direction.  Thousands and thousands and thousands of birds. 

It was over as fast as it began.  By 1/2 hour after dawn, they were gone.

Dusk was different.  Half an hour before sunset the flocks approached the site but did not roost.  Instead some flew around it, some perched.  By sunset all the birds were flying and again the sky was thickly peppered with an incredible number of birds.  As I watched through binoculars I noticed the furthest birds were flying right to left, the nearest left to right.  They were circling the roost counter clockwise!

As the sky darkened small flocks broke off and disappeared to roost in evergreens.  By 1/2 hour after sunset, they were done.

This phenomenon leaves more questions than answers.  Why did they choose this place?  How did they find it?  Do they come here every year?  When did they begin roosting here this fall?  How much longer will they stay? 

And just how many robins are there?   No one can say.

Scattered snow flurries. High 22^oF.  Low 12.  That was the forecast and the birds were eating like crazy.

On days like this I think about the challenges birds face outdoors.  They are outside in every kind of weather and have to cope with it, no matter what.  It turns out that eating is the best defense against freezing to death.  Food is the fuel they burn to stay warm.

The birds we see in Pittsburgh in the winter are those who eat the kinds of food we still have available.  Sparrows, cardinals and woodpeckers eat seeds, suet and dormant insects.  Hawks and owls eat rodents and other birds.  Starlings, crows and gulls eat anything, including garbage.  

The colder it is, the more they have to eat to stay warm,  In Winter World: The Ingenuity of Animal Survival by Bernd Heinrich I learned that “if [golden-crowned] kinglets go without food for only one or two hours in the daytime, they starve (and freeze) to death.”   Birds burn up enormous amounts of calories to stay warm.

In the worst of winter I try to help the seed-eaters, and indirectly the hawks who eat them, by putting out bird seed.  They are all grateful to have found an easy source of food.  I have tried commercially made suet (animal fat with added bird seed) but it’s not popular with my avian visitors.  Marcy Cunkleman makes her own suet from scratch and it’s a great success.  You can tell by her photo of a plump red-bellied woodpecker at her feeder.

We humans are now largely insulated against the rigors of coping with cold.  We have built permanent shelters and figured out how to use fire to heat them, whether directly through burning wood, oil or gas or indirectly by burning coal for electricity. 

But I think our bodies have not forgotten our ancestral past when we lived outdoors all the time.  As winter comes we eat more and cook more.  No wonder the holidays are so replete with food.  No wonder we eat so much and then vow to go on diets in the new year.  Now that I understand how cold triggers eating, I know why those diets are so hard to accomplish in January.

If you’ve been reading this blog for a while, you know I like crows, but you may not know I like ravens even better.

This is partly because I’ve read some great books about them:  Mind of the Raven and Ravens in Winter both by Bernd Heinrich, In the Company of Crows and Ravens by John M. Marzluff and Tony Angell, and Bird Brains: The Intelligence of Crows, Ravens, Magpies and Jays by Candace Savage. 

In every case, ravens shine.  They are one of the most intelligent birds on earth, persistent and innovative in solving problems and known to outwit other critters, a feat which earned them human tributes as tricksters and gods.  Ravens even play.

In this part of eastern North America, ravens are thought to live only in the mountains, far from people, but last fall Chuck Tague photographed a pair of them at Western Penitentiary along the Ohio River.  My interest was piqued!

On New Year’s Day I drove along the Ohio to a spot near the McKees Rocks Bridge.  I was looking for peregrines and wondering if there were any suitable nesting sites near the Penitentiary.  

I didn’t find any peregrines, couldn’t see any nest sites.  I was disappointed, driving away, and muttering about a wasted afternoon when a raven jumped down on the road ahead of my car.  Wow!  She started to pick up something on the road but it worried her and she did a jump-back.  Then I saw the second raven, clinging to a bridge abutment, eating gravel from a crumbling spot in the cement and flapping to stay up there.  Double wow! 

I pulled off the road to watch.  It was late afternoon and the ravens were getting ready for dinner.  The one who ate gravel was filling his crop with grit so he could digest the delicacies to come. 

I hadn’t even noticed the nearby dumpster until the male raven (he’s larger) flew to it and began to inspect the bags.  He carefully picked open a hole and began pulling out garbage and discarding the inedible: foil, styrofoam plates, napkins, boxes.  Jackpot!  Chicken bones!

His mate began working on another bag.  She pulled out paper, folders and coffee cups.  Bummer!  Office supplies!  She gave up and walked the dumpster rim to the male’s side and tried to get a piece of the action.  He wasn’t mean about it but it was clear he was in charge and she couldn’t reach the bag.  She hopped up and over him twice.  Eventually he was sidetracked by a particularly nice bone and she was able to sort through the bag uninterrupted.

I was fascinated and wanted to watch longer but the area is a rather creepy place - all the better for ravens who don’t want to be bothered by people.

I know what you’re thinking.  How could I get so excited about birds eating garbage?  Check out the videos at PBS’s NATURE episode on Ravens, especially The Bird in Black and you’ll see what I’m looking forward to - right here in the city!

Happy New Year! 

Many birders start a new list each year of the birds they see.  I don’t, but I still like to note the first bird on January 1.

I would have to be deaf and blind to have missed the first bird this morning.  Even before dawn a flock of crows swirled over my house like a vortex.  Today it’s windy and the crows looked like black rags flapping in the wind.  Some of them used the wind to dive and climb.

In an unusual move, about 100 of them perched in a tree across the ballfield instead of continuing on their way.  It looked like my drawing - a bunch of black dots clustered at the top of the tree.

As more waves of crows passed overhead, the perched birds shouted at the new arrivals to join them.  What a noisy, boisterous greeting to the new year!