Outside My Window

I captured this photo on the Pitt peregrine webcam today and my first reaction was “They’re soooo cute!” 

These three little white birds are 12-day-old peregrine falcon chicks, Dorothy and E2’s nestlings at University of Pittsburgh.  They’re in the cute downy phase before they start to grow feathers. 

Such bright-eyed babies!  I’m amazed at how white they are.  Even their beaks are white.  And their feet are so large that they sit like little Buddhas with their toes in front of them. 

I can tell they ate recently.  There’s a bulge at the top of their chests showing their crops are full.  (Many birds have crops, a muscular expandable section of the esophagus where they store food prior to digestion.) 

Soon these babies will get sleepy and sprawl flat on their bellies.  

Eating, sleeping, growing.  That’s all they’re going to do until early June when they’re ready to ledge-walk and learn to fly. 

My friends will tell you this bird is a villain, a despoiler of songbird nests, a wrecker of warbler home life.  She refuses to raise her own young, foisting them off on unsuspecting foster mothers.  To make matters worse, she sneaks in and kills the foster mother’s own young so that hers have a better chance to grow up.

This is a female brown-headed cowbird (photo by Chuck Tague). 

I don’t know why she won’t make her own nest but perhaps it’s because cowbirds are nomads, following cattle and buffalo herds to eat the bugs and seeds they churn up.  With the herd on the move, her own nest would be a few counties away in no time.

So Mrs. Cowbird picks on a species that’s slightly smaller and lays an egg at dawn when the warbler or sparrow mother is away getting food.  If she has time, Mrs. Cowbird kicks out the foster mother’s true egg.  Not only that, her egg usually hatches earlier so it gets a head start on its foster siblings.  They die, the cowbird lives.

Sometimes this sneaky plan doesn’t work. 

Gray catbirds are able to recognize their own turquoise eggs.  Cowbird eggs are slightly larger and blotchy white as shown in the composite at right.

When a catbird finds a cowbird egg in her nest, she throws it out. 

In the battle of Cat(bird) versus Cow(bird), the Cat wins.

I’ve watched the peregrines at University of Pittsburgh for many years and have learned something about Dorothy, the falcon who nests there: she is not the best of housekeepers. When she has chicks to feed, cleaning her nest is a low priority.

This trait is individual to Dorothy’s “personality.” If you observe other peregrine nests on webcams, you’ll see that the gravel is usually pretty tidy.

Until yesterday I had hopes Dorothy had changed her ways. Perhaps E2 was having a positive influence. As recently as Wednesday evening the gravel was clean (see photo, top right).

Not so on Thursday! It rained all day and Dorothy gave up. In the second photo the nest is carpeted in prey feathers and the chicks are surrounded by a mess. As my friend Kate says, “Well, that’s what happens when you have young kids.”

Beth Fife of the Pennsylvania Game Commission will have her work cut out for her when she comes to band the chicks this spring. Every year Beth not only has to collect the chicks while Dorothy attacks, but she must drag a garbage bag out on the ledge and clean Dorothy’s nest.

For now, it looks like another messy year. Perhaps Dorothy thinks that Beth provides room service. (NOT!)

It’s been a week since 3 peregrine eggs hatched at the University of Pittsburgh and their parents have been feeding them frequently. 

Have the nestlings grown?  Here’s a visual comparison.

At left are two photos from the webcam, exactly the same size.  The top photo shows the chicks on the day they hatched, the bottom one shows them today. 

Indeed, they have grown.  Each chick is two or three times larger than the remaining egg and the group of chicks takes up a noticably larger portion of the picture. 

Meanwhile the unhatched egg is already a week beyond its probable hatch date.  This egg is unlikely to hatch at all, but don’t worry.  In the seven years Dorothy has nested at Pitt she always lays 4 eggs but about 40% of the time she hatches only 3 of them. 

This outcome is normal.  Eventually one of the adults will move the unhatched egg out of the way.  

At the rate the chicks are growing, they’ll need all the space they can get!

Watch the peregrines in action on the National Aviary webcam. 

Several people have asked me why birds of prey, especially red-tailed hawks and peregrines, would choose to nest close to humans. Isn’t it unnatural? Doesn’t it make them tame? Are the ones who nest on buildings already tame?

In the case of peregrines, whom I know better than red-tails, I can tell you it never makes them tame. To them, we are still their mortal enemies. Instead, conscious or not they have made a calculation: The enemy of my enemy is my friend… and besides, there’s lots to eat.

Birds of prey know that humans can and do hurt them but they also know from personal experience that it is rare. Meanwhile, they have learned there’s an advantage in being near humans because we keep their other enemies away.

A good example is that great-horned owls, a dangerous predator of peregrines, are rarely if ever found on office buildings. Peregrines who nest on buildings have one less worry as they raise their young.

Another advantage is the food we generate. Humans create a lot of garbage and many prey species eat it. For red-tailed hawks, we indirectly provide rodents. For peregrines, our buildings house pigeons and starlings, a ready food supply.

When their nests are successful their hunch about us is reinforced. The juvenile peregrine in the picture is a case in point. She was born in downtown Pittsburgh on the Gulf Tower in April 2007. Her parents made the calculation that the territory was safe with plentiful food and they successfully raised four young birds. As you can see, she was thriving last July when her picture was taken by Matt Frederick as she perched on Roberto Capriotti’s windowsill at K&L Gates in the Oliver Building.

If these birds can put up with seeing humans every day, the rest is easy.

p.s. I wish she’d landed on my windowsill… but if she had, I would have been unable to concentrate for the rest of the day!

Now that the eggs are hatching at University of Pittsburgh, we have two sets of hungry baby peregrines.

On the left:

At Gulf Tower, Tasha2 stopped brooding the chicks long enough for Barbara Simon to capture two good photos.

In the first picture, you can see the two unhatched eggs on the gravel next to the two chicks. The chicks certainly have grown! These two eggs will not hatch at this point and will eventually be moved aside by the adult birds.

In the second picture, Louie brings food for the family. He will tear it into tiny pieces and drop it into the chick’s mouths.

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On the right:

E2 watches from the perch while Dorothy brings food to their first chick.

Click on the photo to see a slide show of Dorothy, E2 and their first nestling of 2008.

You can watch both webcams at the National Aviary website.

For more of my peregrine blogs, click here.

This morning at 8:07am I got a call from my friend Karen Lang.  She saw an eggshell next to Dorothy so we knew the eggs had begun hatching at the University of Pittsburgh peregrine falcon nest.  Congratulations to Dorothy and E2!

When Karen first saw the shell it was a perfect half shell.  As I write, the shell is no longer visible because Dorothy ate it.  However I’ve included two snapshots.

The first one shows what’s left of the shell at 8:37am after Dorothy already ate part of it.

The second snapshot shows E2 arriving to see the eggs hatching.  You can see a little bit of shell next to Dorothy’s shoulder.

I hope to see the chicks soon on the National Aviary’s webcam.

I believe the peregrine falcon eggs will hatch soon at Pitt. Compared to last week, Dorothy is spending more time incubating than E2. In this picture she seems to be telling him, “Get up! It’s my turn.” She has years of experience hatching eggs while this may be his first year as a dad.

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And maybe - just maybe - the photo at right shows some pips (dents) in the eggs. If so, the chicks are starting the exhausting job of breaking the shells.

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Pictures are worth a thousand words.

Here are two snapshots from the Gulf Tower peregrine nest on Tuesday afternoon April 22, thanks to Jamie Sehrer and Joanna Steward. 

In the first you can see the two chicks who hatched on April 20 and two eggs still waiting to hatch.  The baby birds are so tiny and weak they can barely hold their heads above the eggs.  In the second picture, Tasha2 arrives to feed them. 

The chicks cannot regulate their body temperature yet so Tasha will brood them for about 7-8 days.  A brooding mother bird looks a lot like she’s incubating.  The purpose is the same - to keep the babies warm.

It’s been six weeks since the first common grackles came back to Pittsburgh for the summer.  (We don’t have great-tailed grackles; they’re a southwestern bird.)

In the beginning the flocks were made up of males who came early to work out the pecking order before the ladies arrived.

In early April the females started to trickle in.  At first they were in such small numbers that the males outnumbered them and there were loud chases - three guys for every gal.

Now the balance has swung to 50-50.  The ladies are here and the guys are getting down to the serious business of courtship.

I could tell how far the grackle nesting season had progressed when I saw a pair of common grackles courting in a tree near my house.  The male puffed himself up and said “Skreeeeeeeek!”  The female fluttered her wings and said “ee ee ee ee ee ee ee.” 

It must have done the trick because they mated.  More grackles will soon be in the making.