Saturday, October 22, 2005

The mystery of Pale Male's and Junior's orange-chested kids

photo by Cal Vornberger - May 29, 2004
Fifth Ave. nestling, jumping
Photo by Lincoln Karim -- September 1, 2005
Trump-Parc fledgling [f], pondering

Yesterday I posted Part I of my investigations into the mystery of the orange-red coloration of all Pale Male's offspring, and of the similar coloration of the Trump Parc hawk kids.Here is the question I asked famous hawk rehabilitator and field researcher Len Soucy in an interview a few hours earlier: Is orange-red the usual breast color of the thousands of young redtails you've seen over the years, or is it something particular to the Pale Male offspring? I only had a chance to post the question. Then I had to make a train to Conneecticut.I promised to reveal Len's answer the next day.

On the train back last night I checked my e-mail device and found an anticipatory message from John Blakeman. Here it is. After that, at last, a summary of what I learned from Len:

Like the rest of us, you've got us on the edge of our seats awaiting Len Soucy's response to the question of the prevalence of local red-tailed hawk immatures with golden, orange, buff (or whatever -- non-white) breasts.

As you noted, colored breasts on the immature red-tails of Ohio and most of the entire Midwest are very, very uncommon. In reaching my previous conclusion that the Trump Parc eyasses were probably Pale Male descendants, I presumed that the dark breast color was not common in the New York area, either. But in honesty, I've never studied red-tail populations of the East. That's why I suggested reference to someone who might be familiar with regional color patterns. Immature red-tails are famous for getting into trouble in their first summer or fall and many end up in rehabilitation centers. The people who run these places see lots of local immature red-tails. So Len Soucy's pronouncement will be authoritative.

Frankly, I'm hoping that this color pattern does occur in local red-tails. That, of course, would deflate the romantic familial relationships we've pretty much presumed for the Central Park red-tails. As a story, it would be nice if Pale Male, Sr., were indeed the patriarch of the many red-tails now seen in the park. But from a biological perspective, it would be far better if several unrelated adults were the red-tail colonizers of Central Park. A single line of descent from a single patriarch male, even with several different mothers mixed in, would create a narrow genetic base. It would be far better to have several lines of genetic descent, from multiple parents, populating such a small area as Central Park, or even all of Manhattan.

With the greater genetic diversity of multiple lines of descent (if the hawks are not so closely related), the population is much more likely to survive and thrive. Genetic diversity is a key to the survival of small, insular populations. I'm hoping that I was wrong, that a number of local red-tails have been seen with the darker breasts, indicating a much broader range of genes within the population.

And in retrospect, the fact that virtually all of the offspring have had darkened breasts (at least recently, as far as I can recall) might indicate that the genes for this coloration have been in each of Pale Male's mates, and also in this year's Trump Park mother. This trait may be rather common in the area.

Again, I hope I was wrong, that the birds are not closely related, that they are typical red-tails of the local area.


John A. Blakeman

What Len told me

First of all, Len provided a scientific name for that orange breast coloration that has characterized all Pale Male's nestlings since 1995, and that was seen on the 2005 Trump-Parc nestlings as well: Erythrism -- defined, in the American Heritage Dictionary, as "Unusual red pigmentation, as of hair or plumage." The dictionary accents the first syllable.

" I've handled thousands of redtails at the Raptor Trust," Len Soucy began in a phone interview yesterday morning, "many of them first year birds. I'm also a Field Researcher and since 1969 I've captured and banded at least 10,000 Red-tailed Hawks . Most of the redtails we capture are young hawks that have recently fledged and are making their first migration -- first-year birds.

"The great majority of the young redtails we capture and band are white-breasted birds. Similarly, the young redtails I see at the Raptor Trust, orphans or nestlings that have fallen out of their nests, are predominantly white-breasted.

Very rarely do I see an erythristic first-year redtail. Oddly enough, many of the injured redtails that come to the Raptor Trust as young birds and then stay for longer periods of time [because their injuries are too severe] -- many of these develop that reddish-orangish coloration as they get older. But they started out as white-breasted birds."

Although Soucy insisted that genetics is not his specialty,he was willing to speculate a bit about the mystery of Pale Male's offspring and their unusual chest coloration:

"I agree with Blakeman that it's purely genetic," he said. " And since Pale Male has had multiple mates since 1995, it would appear to be a dominant gene carried by the male. It doesn't make sense any other way."

He agreed with me strongly when I suggested that this common trait makes it more than likely that Pale Male Junior really is a direct descendent of Pale Male [though it is theoretically possible that he is not a son, but actually a grandson]. Len also gave me a few names and phone numbers of other hawk experts, some in the West, who might be more familiar with erythrism among redtail nestlings.. I'll let you know what I learn.

For years we Central Park hawkwatchers have been debating the relationships between Pale Male and the various other redtails we've seen making nesting attempts around the periphery of Central Park. Now we have a strong piece of evidence that at least in this particular case where the nest succeeded and the young were observed, a direct relationship exists. Pale Male Junior is almost certainly a descendent of the famous Fifth Avenue paterfamilias. The other redtails around the periphery are more likely to be offspring too, we have reason to believe; we'll have a stronger clue if any of their nests succeed.

Before I posted this report I wrote again to John Blakeman and summarized Len's information. Blakeman wrote another note:


If erythrism is locally uncommon, then its predominance in the Central Park eyasses raises a number of genetic questions. The fact that all of the recent offspring were erythristic strongly suggests that the trait in Pale Male, Sr. is dominant, and he's homozygous (has two copies of the gene). If so, he's been able to pass down only this trait to all of his f-1s, his kids.
But if his wives, or the mates of his kids don't also have the trait, a few of Pale Male's grand kids should be white-breasted. So far, they haven't been, so perhaps the erythrism gene is also in the unrelated mates. To know this for sure, a few more generations will have to be observed. Pure chance may still be favoring a dominant red-breasted gene. And these things can be influenced by several genes. It may not be a straight Punnett Square genetics problem that we all learned to solve back in high school biology.

PS from Marie
Punnett Square? Is that somewhere near Harvard Square? We obviously missed out at the Bronx High School of Science.

Friday, October 21, 2005

Is Pale Male Junior really Pale Male's son?

Everyone called the red-tailed hawk that raised two chicks on the 35th floor of the Trump Parc Hotel last spring Pale Male Junior because of his striking resemblance to the grand sire of Fifth Avenue. But is Junior really a Pale Male offspring?

And what about all the other redtails who have been trying to build nests in recent years all around the periphery of Central Park -- on Mt Sinai Hospital, on various ledges along Central Park West, or in a niche on the Cathedral of St. John the Divine? Are they all part of the Pale Male Dynasty?

Quite a few months ago John Blakeman, our resident hawk guru, made an observation about the Trump Parc nestlings that held true for all of Pale Male's nestlings of years past: without exception their chests had a conspicuous orange-brown coloring.

Now I and all the other Central Park hawkwatchers had not failed to make the same observation. Of course their chests were orange in color, But for most of us who had never seen any other redtail nestling besides Pale Male's or Juniors, this just seemed the normal course of events for immature redtails. And then John Blakeman, who had seen a great many young redtails in the course of his long exp[erience with the species, expressed surprise at our local hawk kids' chest color. Apparently this was not at all the usual color for baby Buteo jamaicensis.

That's when I wrote my first letter to Len Soucy, who runs the Raptor Trust in New Jersey and who has long been a friend and advisor of the Central Park nature community. I sent it sometime in July. Last week I came upon the letter in a file and wondered why I'd never heard back from Len. Maybe it had gone astray, I thought. Or maybe I never sent it in the first place. I printed the letter out again, scribbled a note on the top and sent it again.

Obviously I had never sent it, for this time I received an answer right away.

I've just spent a fascinating hour on the phone with Len on the subject of the Pale Male Dynasty, and I now believe we are nearing an answer, or at least the beginnings of an answer to our first question.

Here is the letter I sent Len Soucy:

Dear Len,

I’ve been corresponding [and posting on my website] frequent comments from an Ohio redtail expert named John Blakeman. In the course of a discussion about whether the new redtail family at the south end of Central Park is related to Pale Male, Blakeman wrote:

“Already the birds have the very golden breast color that Pale Male's Fifth Avenue progeny had. As I may have indicated elsewhere, this dark coloration is uncommon, perhaps a direct genetic trait passed on by Pale Male Sr. I haven't seen this color here in Ohio red-tail eyasses, but I see only a few of the 5000 Ohio red-tail nests or eyasses. Ask one of the NY or NJ area rehabbers if they ever see this color morph locally.”

Len, I seem to remember that once when I was visiting the Raptor Trust, I saw a redtail in a cage with a reddish-colored breast. Is this something you often see? Or is it a rare thing?

Warmest regards,


[ I have to catch a train. Please tune in tomorrow for the next part of this story.]

Thursday, October 20, 2005

Jack Meyer's walks

Jack Meyer, whom I often recommend when people ask about bird walks in Central Park, has asked me to post the following notice. If you've communicated with Jack before, you'll probably be hearing from him too:

Due to the worsening of an old health problem, I have been forced to cancel
the remainder of my scheduled birdwalks this fall. I am sorry for the
inconvenience this may cause to some of you.

I hope to still be in the park frequently, doing some very casual birding,
and hope I will see some of you then.

I will notify everyone when I resume my walks in the spring.

Jack Meyer

Info on Grackle Roosts

A perfect picture of the Pulitzer Fountain, All that's missing is the grackles.
The statue at the top of the fountain, by the way, is Pomona, Goddess of Plenty.

Below, a paragraph from the Common Grackle account in that authoritative resource, The Birds of North America. [Emphasis mine].Our grackle roost at the Grand Army Plaza of merely one or two thousand birds seems chump change next to a New Jersey roost containing, let's say, 167,000 grackles. [33% of 500,000].

From about Jul to Apr, Common Grackles gather at night in roosting congregations with Red-winged Blackbirds, Brown-headed Cowbirds, and European Starlings. American Robins and Euphagus blackbirds are rarer constituents of these roosts . Roosts are frequently near agricultural fields and orchards; location and formation probably reflect food eaten at this time . Roosts also located in trees lining streets in urban areas , hardwood thickets, conifer groves , or marsh vegetation (including cattail and common reed [Phragmites communis; . Fall roosts in New Jersey (containing 3,000–500,000 birds, 33% of which were Common Grackles) were located in early successional stands of various hardwoods with high tree density, closed canopy that was compact vertically, and mean twig heights from 5 to 12 m . Appears to switch roost sites regularly ; forages during day in agricultural fields and in suburban and urban areas.


Peer, B. D., and E. K. Bollinger. 1997. Common Grackle (Quiscalus quiscula). In The Birds of North America, No. 271 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists’ Union, Washington, D.C.

How EB White might have avoided confusion

A reader from the west coast writes:

Dear Marie,

The Sycamore confusion shows the wisdom of Latin names for plants. Although I can't seem to fit Platanus acerifolia or occidentalis for that matter, into the poem.

To differentiate, Platanus acerifolia has seed pods that usually hang in clusters of two--like cherries. (I believe this cluster of seeds is called an infructescence) P. occidentalis usually has a solitary seed ball. Our western version, P. racemosa's seed clusters hang 3 to 7 on a single stalk like a string of pearls. P. wrightii (Arizona sycamore) clusters seem to branch. As my eyesight gets worse, I have a more difficult time identifying trees--embarrassing for a landscape designer!

Thanks for all you do,
Betty Jo (Camarillo, CA

Let's try it out in the poem, and even go a little farther:

The fountain is dry at the Plaza,
The Platanus acerifolia go bare;
The Hedera helix is sere and it has a
Resigned and immutable air.

No, I'm afraid it won't do, just as Betty Jo predicts. But she provides a reliable way to differentiate the London Plane, [that predominates in Central Park] from the true Sycamore, at least during the fruiting season.

Wednesday, October 19, 2005

Huge Pupa found in park

Last Saturday, October 15, I received an excited phone call from Brad Klein, a Central Park birder and nature lover with a special interest in entomology. "I found a chrysalid near the rocks west of the Great Lawn!" he said. He subsequently sent the following e-mail and several photos, one of which is at left
Hi Marie --

The critter was among fallen leaves and dry grass, and I presume is a species that overwinters on the ground. It did not appear to have fallen from overhanging vegatation etc, but perhaps I am mistaken.

It measures 50mm in length.

Best wishes, Brad

PS These are among the first shots with my new camera. Very exciting.

P.S. I sent these pics to David Wagner, author of Caterpillars of Eastern North America, to see what he says.
Two days later Brad wrote again, having heard from the caterpillar expert:

Dave Wagner has suggested that the pupa is likely a Sphingid moth. More research to follow. I wonder if the critter could be reared successfully. I suppose it's a matter of diapause (the moth's, not mine). Now to find out exactly what that term means.

Marie, perhaps you've the best idea of what hawkmoths are most common in Central Park. Wagner suggested the genus Eumorpha.

I answered:

I'm pretty sure we've never had a sightings of any moth in the genus Eumorpha in CP, though I've had an Achemon Sphinx at our Lost Lake cabin in Putnam County.

These are the 3 Sphinxes on my CP List: : Hummingbird Clearwing [
Hemaris thysbe], Snowberry Clearwing [Hemaris diffinis] and Nessus Sphinx [Amphion floridensis]. The Nessus is quite common. We see it at the Sap Tree at dusk almost every day in early summer

Brad wrote back promptly:

That's interesting. I've seen those three clearwings in the park, but they seem too small for this big pupa.Have you seen their larvae? I have not. The tomato hornworm seems like the kind of critter that might be in the park, since I think they are sometimes raised for school projects.I know that larva is a big one.

A blessed event

Brad Klein, properly holding a large dragonfly [Swamp Darner]he had netted at Balcony Bridge: by the wings.
Photo by M. Winn, taken on July 20, 2005

[see end of posting for another photo, taken one minute after this one]

The day after he discovered the large lepidopteran pupa he described in the previous posting, Brad wrote an addendum:

The amazing thing for me about the pupa was the strong feeling I had that I was personally 'blessed' in finding it. Do you know what I mean? Eight days of continuous rain had just ended. I am walking along surrounded by thousands of New Yorkers enjoying the emerging sun on Saturday morning. I look idly down at my feet, and my sleepy mind slowly distinguishes a shape in the grass and fallen leaves that holds my attention. I stoop down. Incredible! This lovely and mysterious thing. The very symbol of transformation and change.

Tuesday, October 18, 2005

Two final comments on the Linden/Pear fiasco

Received a kindly note from a North Carolinian, Charlotte Reyolds, that made me feel better about my Pear/Linden mistake::

I have a stately tree with heart shaped leaves prominent in the front yard of my farm property in the NC mountains. I always believed it to be a Bradford callery pear, and longed to see the pear’s spectacular white springtime bloom and also its stunning fall orangey red show. I was sure it was a pear, and it looked just like the pears that lined my (and many other) NYC street. However I immediately moved to California and visited the NC farm only during summer and over Christmas / New Year’s.

Then I stayed on in NC for a whole year. No bloom ! I was shocked. No orange show that fall! I was crestfallen. I asked around. Finally the tree was identified as a linden.

Finally, Jack Meyer writes:

I've been following the tree detection with interest. After your first post I tried reading the line in the poem with "Lindens" substituted for "sycamores" and while it didn't have the same rythym as "sycamores" it didn't jar, either .

But "London Planes" just doesn't work. Perhaps White knew the difference, but was taking poetic license. And he would have had to re-write the whole thing had he done it after the trees were replaced with Bradford Callery Pears . That one would never have worked.

Donna Browne: research on Pulitzer Fountain trees with a PS from Marie

Hi Marie,

One thing leads to another.

So these Lindens are actually Bradford Callery Pears
and White's Sycamores are actually London Planes.

London Planes are a hybrid?

Okay, a hybrid of what? It turns out London Planes
are a fertile hybrid of the American Buttonwood
(Platanus occidentalis) and the Oriental Plane
(Platanus orientalis) introduced from the U.S to
Europe in the 17th century. They came from here? Who

Which led to-Wait a second, I've walked through the
Plaza a lot and I've never seen any pears on these
Bradford Callery Pears. And it's got one of those long

Are they some kind of hybrid as well?

Yup. They are a flowering non-fruiting grafted
hybrid, a supposedly non-invasive cultivar of the Callery
Pear, favored as street trees for their compact
branching pattern. Unfortunately because of their
branching pattern, they have a habit at maturity of
having several big branches crash down at once taking
a chunk of trunk with them. Which rather spoils their
looks. Which led to the development of "new improved"
cultivers of the Callery Pear.

Remember I said the Bradfords were supposedly
non-invasive. Well, unforeseen by most humans, those
old unexpected consequences have reared their heads.
The "new improved" cultivers can cross-pollinate with
the old Bradfords causing them to produce cute little
marble sized fruit. Which the birds eat and then
deposit complete with their own fertilizer all over
the place to grow with abandon, causing these
non-invasives to become invasive.

Like I said, one thing leads to another.


(Though note that the Conservancy has very wisely not
made the mistake of introducing the new cultivers into the park proper,
further adding to the park's problems with invasives.)

PS from Marie:
"Compact branching patterns"? It sounds to me like these trees, though not lindens, share with lindens the feature that a roosting flock would need: thick cover .

PPS Tonight I'm bringing an artist to the Grackle-starling fly-in, to provide some specific names for the changing colors at sunset. More about that later.

Monday, October 17, 2005

A red-faced writer

An American Linden leaf

A Bradford Callery Pear leaf
An embarrassed Marie

A few days ago I wrote the following letter to Regina Alvarez, the Woodlands Manager of the Central Park Conservancy:

Hi Regina, I see on the Central Park website that the Grand Army Plaza falls under the jurisdiction of the Central Park Conservancy. I'm trying to trace the history of the trees that form a half-circle around the Pulitzer Fountain in the Grand Army Plaza. Right now there are 10 Lindens there. But there seem to have been sycamores there sometime in the past. Do you have an easy way to track this down?

Thanks a million, Marie

I received the following answer.

Hi Marie -
Those trees down at Grand Army Plaza are actually Bradford Callery Pears, not Lindens. Neil says they were planted in 1979 and, yes, they replaced London Planes (which are Sycamore hybrids). I hope this is helpful.
Needless to say Regina's kind response filled me with chagrin. After going on and on about how writers feel duty-bound to get their facts right, I seem to have gotten every single fact in my reportage wrong!

So here we are: the Lindens that shelter the huge flocks of grackles and starlings at the Pulitzer Fountain are not Lindens. They are Bradford Callery Pears. And the sycamores that obviously surrounded the fountain when E.B. White wrote his poem were not exactly sycamores; they were London Planes, hybridized sycamores.

The lesson: Look everything up, and then double check. Now I have done so, and find the following on an Internet website:

"Completed in 1916, Grand Army Plaza is considered one of the most successful urban plazas in the country. It is a focal point of midtown Manhattan, offering an elegant transition to the Park from nearby skyscrapers. Grand Army Plaza is, in fact, two plazas — each a semicircle bisected by Central Park South. Both halves are surrounded on their curvilinear ends by Bradford Callery pear trees, which provide a natural frame. The split plaza was inspired by the design of the Place de la Concorde in Paris."

PS Wait a minute. I didn't get the sycamore ID wrong. E.B. White did. They were actually London Planes. Now I feel a little better.

PPS In any event, whatever the trees were, and are, one replaced the other and the mystery is finally solved.

Birds after the rains

Savannah Sparrow [an uncommon bird in Central Park]
Photo by Phil Jeffrey
After 8 days of rain the birdwatchers are out in droves. Their reward: a great mid-October birding day in Central Park.

DATE: Saturday, 15 October 2005
LOCATION: Central Park
REPORTED BY: Phil Jeffrey

Loon sp. flyovers (4, probably Common, 10:30am)
Gadwall (2, Harlem Meer)
Northern Shoveler (5+, Harlem Meer)
Bald Eagle (9:30am, over Harlem Meer)
Sharp-shinned Hawk
Cooper's Hawk
Red-tailed Hawk
Merlin (probable)
Chimney Swift (4)
Yellow-bellied Sapsucker
Hairy Woodpecker (Female)
Northern Flicker
Eastern Phoebe
Blue-headed Vireo (several)
Black-capped Chickadee (several)
White-breasted Nuthatch
Ruby-crowned Kinglet
Gray Catbird
Brown Thrasher
Northern Parula
Magnolia Warbler
Black-throated Blue Warbler
Yellow-rumped Warbler
Black-throated Green Warbler
Palm Warbler
Blackpoll Warbler
Black-and-white Warbler
American Redstart
Common Yellowthroat
Eastern Towhee (heard)
Savannah Sparrow (1, Wildflower Meadow)
Song Sparrow
Swamp Sparrow
Indigo Bunting (1-2, Wildflower Meadow)
Brown-headed Cowbird (2, Ballfields)