Monthly Archives: March 2010

Misty morning coots

American Coots on a misty morning, Moraine State Park (photo by Brian Herman)
This was the month that broke winter’s grip.

In early March the lakes were ice-covered, no water birds at all. 

A week later, open water.  The tundra swans passed through.

Mid March, ice free.  Huge flocks of ducks stopped over on their way to Canada’s lakes and bogs.

Now the ice is just a distant memory.  The long range migrants are nearly gone and in the misty mornings coots splash and feed.

March goes out like a lamb.

(photo by Brian Herman)

What’s happening at the Gulf Tower?

That’s the question all the peregrine watchers are asking.

It’s been ten days since Dori won the Gulf Tower site from the previous female resident, Tasha, and eleven days since Tasha laid her last egg. 

For a while neither Louie nor Dori did anything with the old eggs except court and bow over them.  Sometimes Dori pushed them out of the scrape.  Later Louie would push them back in. 

Then over the weekend Louie started incubating Tasha’s eggs for an hour or two at a time.  As is typical for male peregrines, he didn’t incubate them overnight but he showed up when expected — at dawn and early afternoon — as if he was taking his normal incubation duty shift.  Dori didn’t participate. 

This puzzled everyone.  Are Louie and Dori disagreeing about the eggs?  Will Dori refuse to lay her own if the old ones are present?  Are the old eggs viable?  Will Louie eventually give up on them?  Will Dori eventually adopt them?

As much as this seems a drama to us, something very simple is going on.  Louie and Dori are at different stages in the nesting sequence.  He has eggs, she doesn’t.  When she lays eggs she’ll catch up to him.

Keep in mind this couple has known each other for only ten days.  If their courtship goes well — and that appears to be the case — Dori’s hormones will trigger egg laying.  She can’t “refuse” to lay eggs.  She won’t have any choice about it, and she’ll have to put them somewhere.  The only thing she could possibly refuse is the ledge where her rival nested, but she hasn’t done that.  She courts at the nestbox, she rearranges the gravel and she digs at the scrape where the old eggs were laid.  Dori will lay eggs when she’s ready.

Humans are impatient during a slow drama like this one.  Watching the webcams is a lot like watching television where we expect the action to unfold a lot faster.  But remember, the nature programs leave out all the boring bits.  They have only an hour to show you a whole year of a bird’s life.

Give this pair some time.  Nature is taking its course.

p.s. The old eggs might not be viable.  If so, the adults will move them away if they don’t hatch.

(photo of Louie from the National Aviary webcam at Gulf Tower.  Thanks to Traci Darin for the screen capture.)

First Leaves

I’ve been watching carefully and now I’ve seen them.  Our post-winter landscape is dotted with blotches of pale green.  The first leaves! 

What plants are these that sprout first?

In my neighborhood they’re bush honeysuckle, an invasive woody shrub that thrives almost anywhere.  I haven’t bothered to determine the species, there are so many: Amur (Lonerica maackii), Morrow’s (Lonerica morrowii), Tartarian (Lonerica tartarica) and more.  All of them, alas, are invasive.

Non-native plants often thrive because they’re out of synch with our seasons.  They’re the first to produce leaves and the last to drop them because they’re responding to the amount of daylight in their place of origin.  Bush honeysuckles come from Asia, Turkey and southern Russia so they open their leaves just after the spring equinox, at least a week ahead of our wary native plants.  They’re not hurt by being early because they’re hardy enough to survive a late frost or snowstorm.

Knowing all this, I should be upset that the bush honeysuckles are leafing out.  But I can’t help it. 

We have leaves!

(photo by Marcy Cunkelman)

Signs of Spring: Spicebush

Here’s a flower that’s one of the first signs of spring in Pennsylvania’s woods and it’s blooming right now.

Northern spicebush (Lindera benzoin) is a native shrub, 6-12 feet tall, that grows in moist locations in woods, valleys and along streams.

In March and early April its small yellow flowers bloom, clustered on the stems before the leaves emerge.  There are so many flowers that the bushes look showy in our otherwise brown landscape.  Don’t be fooled by this close-up, though.  The flowers are quite tiny.

Spicebush is the host plant for the Spicebush Swallowtail, a beautiful butterfly whose caterpillar form looks funny with a huge, fake face “painted” on its back.  You can find these caterpillars eating spicebush leaves in the summer.  (Click here to see.)

By fall the flowers have become small red berries, called drupes, which provide good food for birds.  Robins and catbirds are particularly fond of them.

When you’re out in the woods, look for spicebush.  You can identify it by smell — that’s how it got its name.  Just run your fingernail along the bark and smell it’s spicy, aromatic scent.

(photo by Marcy Cunkelman)

Anatomy: Breast

It’s Friday! and time for the Bird Anatomy lesson.

As I said last week we’ve hit a patch of easy anatomy terms as we move down the underside of the bird.

Today’s body part is the breast.   And here’s a rose-breasted grosbeak to illustrate its location. 

Under those rosy feathers are the breast muscles, the largest, strongest muscles in the bird.  They are so large they comprise 15-20% of its body weight. 

They’re the flight muscles that pull the wings both up and down.  In most birds the downstroke is the power stroke, so those muscles are the largest.  The upstroke muscles return the wings for the next flap and are ingeniously rigged like pulleys to make the job easier. 

You can see these structures in a whole chicken breast from the grocery store.  Chickens have been selectively bred to produce a tasty bird for humans so what you see on a grocery store bird doesn’t have quite the same proportions as what the peregrine sees when he dines on a pigeon, but you’ll get the idea.

(See how I couldn’t help but include peregrines in this?)

(photo by Marcy Cunkelman)

New female peregrine at Gulf Tower!

Something strange has been going on at Gulf Tower since last weekend.  Now we know why!

It began Friday night, March 19.  Tasha sat on the nest at 10:40pm and watched the sky.  Within minutes she stepped out of view and from that point onward we heard periodic wailing for most of the night, though no peregrine was visible.  Wailing can mean many things including “come here” and “stay away,” but it isn’t the sound of peregrines locked in combat. 

That night there was no evidence of a fight at the nest — no fight sounds, no birds on camera. 

An hour before dawn Tasha returned to the nest and slept.  Half an hour later Louie arrived and tried to bow with her but Tasha would not bow.  She looked at him, then left to tackle whatever was out there.  It was a young female peregrine challenging her for the site.

For three and a half hours nothing happened.  Silence.  Then Tasha arrived at the nest, all pumped up and running on adrenaline (if peregrines have adrenaline).  She was sleeked for battle and her left wing drooped, an old injury she hid most of the time.  She shouted excitedly to Louie and left quickly.  

Louie lingered at the nest for several minutes.  At one point he stood over Tasha’s two eggs, yipping softly, but something in the sky soon distracted him and he bounded off stage.  In half an hour Tasha appeared again very briefly.  That was 10:45am, the last time she appeared on camera.

Seven hours of silence.  Nothing except for two brief visits by Louie alone. 

Then at 5:45pm Louie arrived at the nest and called, “Come bow with me.”  His audience needed encouragement.  He called and called, bowed and bowed.  Finally his new lady arrived, a female peregrine with a pale back, no white wing feather and in top physical condition.  For the next several hours they repeatedly courted at the nest.  She was now his queen.

That was Saturday night, March 20.  There are no video archives for several days after that, but everyone watching the falconcam knew the situation was odd.  Why were two peregrines at the nest but no one incubating the eggs?  

Yesterday Dr. Todd Katzner of the National Aviary went to the Gulf Tower to solve the mystery.  He was able to observe the new female and read her bands as she courted with Louie: black/green M/93.  Born at the Landmark Building in Akron, Ohio in 2007, her back is paler than Tasha’s and her wings are normal.  She has no white wing feather. 

Since Monday the fervent peregrine watchers at Make-A-Wish, whose offices are near the nest, suspected Tasha was gone forever.  They’ve been Tasha’s fans for many years and were sad about this turn of events, so they wanted to honor the new female with a happy, hopeful name.  Even before they knew her identity they called her Dori, which means “wish” in Romanian. (*)

Dori has wanted to nest in Pittsburgh for quite a while.  She first tried the 62nd Street Bridge where she was identified last October by Dan Yagusic, but she kept a lonely vigil there, unable to attract a mate to the site.  In January Dan found her at the 40th Street Bridge, still alone.

As spring approached her hormones kicked in as they do for all peregrines.  Dori needed a nest and a mate.  The bridges were fruitless.  She flew downstream… and the rest is history.

Tasha was a very successful peregrine.  When she disappeared last weekend she was at least 14 years old and had raised 44 young at the Gulf Tower.   

We wish the same great success for Dori.  May she live long and have many babies!  

And, yes, we’re all watching for her first egg.

(two snapshots of Dori from the National Aviary webcam at the Gulf Tower)

p.s. Remember the video of two peregrines courting on Saturday evening?  I was wrong!  Tasha isn’t in that picture.  They’re Louie and Dori.  Click here to watch.

(*) Dori has many names.  Dori is her nest site name, Mary Cleo is her banding day name, and Louie has a special name for her that is unpronounceable by humans.

Heron Sunrise

Great blue herons' nest at sunrise (photo by Chuck Tague)
Great blue herons’ nest at sunrise (photo by Chuck Tague)

Great blue herons are very large birds.  They’re four feet tall with a six-foot wingspan and weigh over five pounds, yet they nest in rookeries high in the trees.

The nest is the focus of their family life.  Because they are seasonally monogamous, their first order of business when they return in the spring is to attract and court a mate.  They do this at the nest with elaborate courtship displays initiated by the male.

Before he has a mate he circles the rookery in exaggerated, laborious flight, then lands with his head and neck plumes erect and croaks his Landing Call.  On the nest he does the Stretch Display, extending his neck and raising his bill to show off his beautiful throat plumes, then lowering his head and moaning.

He preens his wing.  He fluffs his neck.  He raises his crest.  He grabs a twig on the tree and gives it a shake.

He does his utmost to get noticed!

When a female heron agrees to be his mate their displays become elaborate duets.

In the Greeting Ceremony a heron returning to the nest where his mate is waiting will give the Landing Call while his mate does the Stretch Display.

The Stick Transfer ceremony is an exaggerated drama of nest building.  The male arrives with a stick for the nest.  The female does the Stretch Display and takes the stick while he rapidly claps the tip of his bill at her.  Then she places the stick on the nest.  Ta dah!

They even have a ceremony for Nest Relief.  The arriving heron gives the Landing Call, his mate on the nest does a Stretch Display, then they both clap the tips of their bills and sometimes preen.

If you watch at a heron rookery you’re most likely to see these displays at dawn or dusk because the females leave the area during the middle of the day.

So plan your next adventure for early morning and have a heron sunrise.

(photo of nesting great blue herons in Florida by Chuck Tague)

p.s. Click on the imbedded links above for photos of the courtship displays or click here for a photo sequence.

Heron Rookery

Have you ever seen a tree that looks like this?  With a lot of big nests in it?  Surrounded by trees with similar nests?  If you’re in southwestern Pennsylvania, you’ve found a great blue heron rookery.

Great blue herons nest colonially near creeks, rivers, lakes and wetlands.  Their group of nests is called a rookery after the colonial nests of the Eurasian rook, a common bird like our crow that’s called a “rook” because of the sound he makes.

Great blue heron rookeries are large, often containing several hundred nests that are used year after year.  In Pennsylvania they’re usually located in sycamores in an isolated place on an island or in a wooded swamp.  The location is chosen for its access to food and isolation from predators, but food doesn’t need to be right there.  Adult herons will commute nine miles on foraging missions, so the heron you see hunting koi in your backyard pond may well have flown a long distance to get food for his kids.

In March the great blue herons return to Pennsylvania to set up housekeeping.  Even from a distance you can see them standing on the old nests making home improvements, a twig here, a stick there. They also do elaborate courtship displays on the nest including stretching, bill snapping and a crest raising display.  They look too large to use the nests, but I’ll show you how they do it in tomorrow’s blog.

If you have the chance now’s the time to notice heron rookeries, for in six short weeks they’ll be hidden.  The trees will be covered in leaves by May.

And remember, if you find a rookery don’t disturb the birds.  They’ve chosen the site because it’s isolated from predators, including humans.  Herons will abandon a rookery where the disturbance becomes too great.

(photo of great blue heron rookery in a sycamore tree by Tim Vechter)

Dorothy surprised me

For the first time ever Dorothy, the female peregrine at the University of Pittsburgh, has laid five eggs.  This is her ninth nesting year and she’s always laid four eggs, so there was no reason to expect she’d lay a fifth this afternoon.  But there it is.

E2 ‘s going to have his work cut out for him when it’s time to feed them!

(photo from the National Aviary snapshot camera at University of Pittsburgh)

Thoughts of Love

In the spring, a young man’s fancy lightly turns to thoughts of love Alfred Tennyson

And so it is with birds.

It’s really spring now.  The raptors are courting and laying eggs, robins are singing as they migrate home and pigeons are billing and cooing.

Pigeons?” you say.  Pigeons are the urban peregrines’ major food source so I’m rather fascinated by them.  And they’re easy to observe.

Who hasn’t seen a male pigeon puff his throat, fan his tail and coo and strut circles around his lady?  Sometimes he drives her (chases) to separate her from the other males.  This seems promiscuous, but pigeons mate for life.  They’re just doing the ritual to “get in the mood.”

Mated pairs also preen each other in courtship and like many birds the male feeds his mate.  Columbids feed their young by regurgitation, so they touch bills to offer food.  When you see pigeons billing and cooing, the male is demonstrating he’s a good provider.

Pigeons also have a courtship flight display that makes a noise.  The male flies out, clapping his wings three to five times on the upstroke (yes, he smacks the upper side of his wings together) and then glides with his wings in a V.

Birds of North America says this wing-clapping is usually a post-copulatory display.

I’m hearing it a lot lately.  Yes, the pigeons have turned to thoughts of love.


(photo by Aomorikuma via Wikimedia Commons, GNU Free License)