Outside My Window

I’ve watched the falcons at University of Pittsburgh for many years and have learned something about Dorothy, the female peregrine 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!)

I saw a lot of birds in northwestern Ohio last weekend - in fact the count of species may have been a personal record - but the best bird by far was this beautiful prothonotary warbler.  He was so stunning he attracted a crowd. 

This picture may make you think the prothonotary perches out in the open all the time, but don’t be fooled.  Though his bright yellow body is easy to see before the leaves come out, he forages low on branches in woody swamps and spends his time walking among the tangles.  It took a lot of snapshots and patience before Chuck Tague got this picture. 

Seeing a prothonotary warbler is always a treat, especially because I’m from Pittsburgh.  These warblers are southeastern birds whose northern range extends to the Great Lakes, but they don’t spend any time here.  Their favorite habitat is flat land in wooded swamps, a setting notably missing from southwestern Pennsylvania.  The only place I can reliably find them is in the glaciated area near Pymatuning.  And then I’m lucky to see one even there.

All of which makes this warbler the Best Bird and my favorite memory of last week’s trip to Crane Creek and Magee Marsh, Ohio. 

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!

For a peregrine fanatic this is a hard time to be away from Pittsburgh - what with baby peregrines in two nests and lots to watch - but migration is in full swing and the warblers beckon. There are lots of birds flying north, birds who barely stop to eat on their way to Canada, and I don’t want to miss them.

That explains why I’m at a Magee Marsh in Ottawa County, Ohio with Chuck and Joan Tague right now and we are looking at beautiful warblers. For many Pittsburgh birders a May pilgrimage to northwestern Ohio has become a tradition.

Last year when we made this trip we also took the ferry to Point Pelee, Canada, a sand spit that points south into Lake Erie. It was foggy the whole way and we were barely able to see the islands as we made the crossing. At the tip of the peninsula in Canada we found warblers galore. They too had made the foggy crossing and were desperate to eat before flying onward to their homes further north.

This bay-breasted warbler was so busy eating that he didn’t care that we watched him. He had completed most of his journey from Venezuela to Canada’s boreal forest and he was hungry. He walked the branches at eye level and cocked his head while Chuck Tague took his picture. Then he followed as we continued our walk. It was almost as if we’d made friends with him.

Not really. But the warblers do come this close during migration along Lake Erie’s shore. That’s why I’m here.

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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Last week the trees put on their best apparel, all decked out in flowers. The weather was fine - not cold like today. Here are some memories from last week’s beautiful weather, captured on my cell phone camera.

An apple tree in full bloom behind WQED’s offices. It looked lovely and smelled sweet, the quintessential flowering tree.

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A London plane tree in Greenfield sporting red and green balls. The balls are covered with the tree’s tiny flowers. When the flowers are fertilized, the balls become seeds that break up and float away in the wind the following spring.

This tree is a hybrid of the Oriental plane tree and American sycamore. Many of them were planted in Pittsburgh more than 100 years ago because they are very tolerant of air pollution.

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A sugar maple in full flower. From below, its flowers look like fluffy, pale green, hanging leaves but they are actually bunches of small flowers suspended on long stems. They are pollinated by both insects and wind.

And yes, the pollen count was high last week.

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There’s a place on my lunchtime walk where bumblebees have nested for many years.  In April they become quite active near a tall privet hedge.   Since I don’t want to be stung I have never looked for the hive.  I don’t need to see it that badly!

But I still encounter the bumblebees.  They use the airspace between their hedge and a telephone pole for hovering.  In doing so, they usurp the sidewalk.

I’ve read that bumblebees don’t do the waggle dance that honeybees are famous for, but there’s certainly some kind of information being exchanged among these bees.  I always find at least one hovering at eye level over the sidewalk.  Sometimes as many as three are engaged in hover-and-zoom activity. 

I usually step into the street to avoid the bees but the other day I was not in the mood to give way and there were cars in the street.  Since only one bumblebee was hovering over the sidewalk I approached slowly with frequent pauses, hoping I wouldn’t make her angry.   

She didn’t get mad.  She just refused to move.  If I was going to win this contest I would have to literally bump into the bee as it hovered in front of me.  No way.

I stepped into the street … and so I joined in the bumblebee’s dance.

(Thanks to Chuck Tague for providing this picture on short notice.     NOTE ON APRIL 28:  Ooops!  Chuck tells me this is a carpenter bee!  Well, that’s what I deserve for talking about bumblebees on a bird blog.)