Saturday, May 19, 2007

Blakeman responds to DEC letter; suggests close-up photos

Nest in March, 2007
photo courtesy of


In regard to Barbara Loucks' assessment of the Fifth Avenue nest you posted day before yesterday, let me say that I've seen a multitude of wild red-tail nests with giant piles of sticks, along with equal numbers of shallow nests. The number of sticks has very little correlation with success. The extent, nature, and density of lining material is the crucial matter, one that presently we have no knowledge of at 927 Fifth Avenue.
Her implication that the reasons for many nest failures simply can't be known, is inaccurate. The breeding biology of raptors in general and red-tails in particular is not a mystery. There are a number of biologists who know what's supposed to happen, and have the right questions to ask when there is a nest failure, as at 927.
Digital close up photos of the nest are urgently needed. What is the lining material? How is it arranged? Can we see any of the pigeon prongs visible?
I can state that if such photos show any portion of the prongs extending observably into the lining material of the nest, they are the direct cause of the failures. Baring proper egg analyses (ever more unlikely again this year), prompt photos of the nest from above will be revelatory.

John A. Blakeman

Friday, May 18, 2007

Mac's Pack--an inspiring story

Mac's Pack--Joe, E.J., Kathleen with 8/9ths of an unseen future Macpacker, and Lyla McAdams

This year E.J. McAdams, formerly the executive director of the NYC Audubon and now with The Nature Conservancy, participated in NYCA's fundraising event, the City Birding Challenge. He wrote to say that he was planning to take the Challenge under the name Mac's Pack with his entire family participating. Who could resist such a wonderful endeavor? I pledged $1 for each bird they saw that day, but added an additional incentive for the kids. I offered $1.50 for the birds Joe, age 7, spotted, and $2 for Lyla's finds. Lyla is 5. Here's E.J.'s letter with the results.

Dear Marie,

Thank you for supporting Mac’s Pack this year on our quest to spot 30+ species and raise over $1,500. We were successful on both counts!!

Despite Lyla’s (age 5) dream of swarms of starlings the night before, which I assumed was a bad omen, Saturday was a peak migration day in Central Park. Every oak in the Ravine in the North Woods seemed to have another migrant flitting in its branches.

The kids really participated this year. Joe and Lyla brought their own Central Park field guides and identified the birds they knew. Those extra eyes made the difference – we saw 36 species and we did not finish in last place!! We came in seventh out of eight teams. The winning team, the Boroughing Owls, saw or heard 147 species in the 24 hour period. Who would have thought NYC has so much bird diversity.

Although the final results won’t be in until the end of June, it looks like Mac’s Pack took the lead in fundraising for the Challenge. Thanks to your generosity we raised over $3,000 for NYC Audubon and its mission to protect the wild birds of New York City.

Marie, we couldn't have done it without you. Your challenge added a whole new level of fun and incentive. The kids got excited about the extra pledge and they did spend some time preparing. Joe in particular had to practice patience, giving Lyla first chance to name a bird before he named it. It was hard for him but he did a good job.

To fulfill your pledge, which I calculated as $42.50 (see list below and please double-check), please send a check made out to NYC Audubon with “Mac’s Pack” in the memo line to:

City Birding Challenge (Mac’s Pack)
c/o NYC Audubon
71 West 23rd Street, #1523
New York, NY 10010

Note from Marie: Though this website shuns ads and commercial messages, [except for myself, I guess] here's one I can include without a guilty conscience:

If the McAdams' family birding adventure inspires you as much as it did me, you can add to their total, [and support the worthy NYC Audubon, by sending a check to the address above. I believe that getting kids involved with nature at an early age is a crucial conservation goal. They will be the wildlife stewards of the future.

Here's the Mac Pack bird list:

Double-crested Cormorant (E. J.)
Great Egret (E.J.)
Black-crowned Night-heron (Joe)
Canada Goose (E.J.)
Mallard (Lyla)
Red-tailed Hawk (Joe)
American Kestrel (E. J.)
Herring Gull (E. J.)
Rock Pigeon (Lyla)
Chimney Swift (Joe)
Red-bellied Woodpecker (E. J.)
Eastern Kingbird (E.J.)
Warbling Vireo (E. J.)
Blue Jay (E. J.)
Carolina Wren (E. J.)
Swainson’s Thrush (E. J.)
American Robin (Joe)
Gray Catbird (Kathleen)
European Starling (Lyla)
Northern Parula (E. J.)
Chesnut-sided Warbler (E. J.)
Black-throated Blue Warbler (E. J.)
Yellow-rumped Warbler (E. J.)
Black and white Warbler (Kathleen)
American Redstart (E. J.)
Ovenbird (E. J.)
Northern Waterthrush (E. J.)
Common Yellowthroat (Joe)
Hooded Warbler (E. J.)
Canada Warbler (E. J.)
Scarlet Tanager (E. J.)
Northern Cardinal (Kathleen)
Red-winged Blackbird (Joe)
Common Grackle (Joe)
Baltimore Oriole (E. J.)
House Sparrow (Lyla)

Total = 36 species

My previous letters to DEC and their replies

On 5/10/2007 4:33 PM I wrote Barbara Loucks and Chris Nadareski of the DEC:
Dear Barbara and Chris,

I understand from a conversation with Ward Stone two days ago
that you have agreed to undertake the removal of this years's eggs from
the nest at 927 Fifth Avenue. I'm writing to assure you that this idea
has the complete support of the Central Park hawkwatching community.
I've also spoken to Ygal Gelb at NYCAudubon, and know that they too,
are eager to have this happen.

Based on hawkwatchers' records, incubation began this year on
March 11th. That's the day Lola began spending nights on the nest and
when exchanges began. But even assuming that this is not a precise
date, and incubation began a week later, there is no chance that the
eggs will still hatch. Meanwhile, we are afraid that there is a chance
that if the eggs are not retrieved soon they might again prove to be
too decayed to provide answers to our questions about the causes of the
three-year nest failure. .

The fact that Pale Male is fifteen years old certainly makes it
possible that his fertility has been the major factor in the nest
failure. I know there are people convinced that this is the case.
Nevertheless, the nest's success until precisely the moment the new
structure was put up on the 12th floor ledge, though perhaps completely
coincidental, does raise questions and does require that doubts about
fertility be once and for all resolved. This, of course, will be easy
to accomplish if the eggs are retrieved and the egg material is
microscopically analyzed before it is too decayed.

Meanwhile, let me mention that I and the Central Park community
understand that
retrieving the eggs with the redtail pair still in residence will not be an easy job. Please don't think that we take
your willingness to undertake it lightly. We are relieved and grateful
that you are willing and able to retrieve the eggs. This letter is only
to encourage you to do it as soon as possible so that it will not, once
again, leave us without conclusive answers to our questions.

Yours most sincerely,

Marie Winn

PS In regard to the fertility question, I might also mention that last
year I spoke at length
about redtail fertility with Ward Stone, Len Soucy, and Cal Sandfort of the Peregrine Fund's Center for Birds of Prey in Boise Idaho . I found that all three felt somewhat doubtful that a 13- or 14-year-old red-tailed hawk would prove to be infertile
after being
seen that year copulating with undiminished vigor and frequency,
especially when these observers could compare his behavior with that of
previous, successful years.

After weeks of waiting this letter seemed to lead to real results. Here is Barbara Loucks' reply:
    Yes, we will be collecting the eggs this Wednesday. We have a very busy day planned but will squeeze it in in the am.  

To address a few of your other comments, you imply that if the eggs are gathered quickly enough that it will be easy to accomplish that "doubts about fertility be once and for all resolved ". I have to disagree. All it will tell us is the condition of these eggs. We may never know why they have failed the last few years, just as we generally don't know why other raptor nests fail in the wild.

While we may be curious, and would love to know, and are disappointed when young are not produced, there may never be "conclusive answers" about this particular situation. If a new, younger male were to show up or a new female, and they were immediately successful, that might lead one to draw conclusions (that may or may not be correct). If these eggs once again contain no embryos, we can also speculate. Since Pale Male isn't banded, he could be older than 15, even much older.

I would also disagree with your comments concerning frequency and vigor of copulation indicating fertil
ity. It does not guarantee successful fertilization /hatching. From the pictures I have seen on the web this spring, I think the nest looks good again, a lot of sticks. We'll let you know what we find.

I replied to that letter as follows:

Thanks for your answer. I appreciate your time and patience here. Three more points:

1. We do know how old Pale Male is quite exactly, because when he was first seen in Central Park in 1991 he was a browntail. [Hawk experts have noted the uncommon though not unprecedented fact that he bonded with a female and built a nest before he gained adulthood.] According to Ward, it is likely that his first two nests on Fifth Avenue [1993 & 1994] failed because of immaturity. [Ward analyzed decaying egg material from PM's 1994 nest. His report was the same as in 2006 -- no embryonic material visible] Pale Male's third breeding attempt, in 1995, yielded two chicks. Every subsequent nesting year was successful [total = 23 chicks] until the year after the nest was removed--2005.]

2. I was given to understand by Cal Sandfort and by Ward Stone that a simple test of the egg material will reveal unequivocally whether the egg was fertilized. [I'll include a copy of a paragraph from my interview with Dr. Sandfort at the end of this note.] A microscope study will reveal only haploid cells if the egg was unfertilized. The presence of diploid cells indicates fertilization, whether there is any embryonic material visible or not. If the eggs were fertilized and then chilled in the earliest stages, for example, there would be no visible traces of embryonic material. But there would be diploid cells to be seen under a microscope. I understand that once the eggs are in an advanced state of decay, however, this test becomes difficult if not impossible to accomplish. This is why speed is of an essence now.

3. Re "the nest looks good" :The problem may not be the actual "cradle" structure. It may be a combination of the cradle and the anti-pigeon spikes that were included inside the cradle. The spikes were critically important when they were the only thing anchoring the sticks to the ledge. When the nest was removed once before, in 1993, the spikes were left in place, and the hawks easily rebuilt the nest in 1994. But in 2004 the spikes included in the cradle may have been anti-productive, either by impeding egg rotation, or by somehow conducting cold to the eggs. In retrospect
it might have been better not to include them. The cradle now was sufficient to contain the sticks. Of course I remember well that the hawkwatchers were fixated on the importance of the spikes -- being shocked when they were removed along with the nest in December 2004. Everybody then wanted the spikes included in the cradle. And of course I know this is all speculative. would simplify everything if we could establish whether the eggs were fertilized or not. For if they were NOT, there we have a very simple answer for why the nest has been failing for the last three years..

From 2006 interview with Dr. Cal Sandfort of The Peregrine Fund's Center for Birds of Prey, Boise, Idaho

C.S. "If the embryo died between 1 and 4 days after it was laid, if you opened it up you wouldn't be able to see anything. There wouldn't be enough embryonic tissue, blood vessels and so forth to amount to anything you could see visually."

M.W.: Well,, could you still find out about those 1-4 days is some way?

"Yes, there's a stain. ... you can stain the blastodisk -- the initial embryonic material -- the way you stain bacteria on slides, and in that way you can determine fertility even before you have very much embryonic development. An infertile egg does not stain. There's no blastodisk there to stain"

Here is another viewpoint, from a biologist [John Blakeman] I've been corresponding with.

Unfortunately, the study of the retrieved eggs last year [2006], as I understand it, was only able to do a gross anatomical examination, no cellular or tissue studies. This did not determine the "ploidy" of the eggs. If the cells were diploid, they would have had a complete, double set of chromosomes, half from Pale Male and Half from Lola. If the cells were haploid, having chromosomes from only Lola, they would have been definitive evidence of Pale Male's impotence.

I'm not convinced that the lack of gross embryonic structures in last year's eggs indicated haploidy, non-fertilization. The eggs sat on the nest un-refrigerated for weeks before being retrieved. The delicate embryonic tissues could have enzymatically degraded, even without bacterial contamination. There are biochemical tests that could have been used to determine the former presence of an embryo. If the eggs were cooled from the start of incubation, the microscopic embryo would have never developed and couldn't be seen upon gross examination.
He added:

Other than staining the blastodisk, another way may involve DNA analysis. After things have degraded, this may be the only way to do this.

PS to Barbara from Marie -- I know DNA analysis and perhaps other methods of microscopic analysis may be expensive. I believe there are funds available, from interested Pale Male fans, to cover these expenses.

Dear readers -- that's the correspondence. You have my latest letter and Loucks' final answer on the preceding post. I don't think there's anything else I can do. 

STIMIED!: Reply from DEC

For the record, here's the note I e-mailed to Barbara Loucks at the DEC yesterday, followed by the answer I just received.

I'm not going to write Loucks back -- I know futility when I see it -- but I must say that the words "possibility of a renest" , after our experiences of the last two years, seem extremely odd.
[I will post the entire correspondence, including the "earlier lengthy e-mail" as soon as I have time. ]
Dear Barbara,
Everybody in the Central Park birding community was happy to hear that the eggs would be retrieved on Wed, 5/16. I wonder if I may report back to them that the eggs were, indeed, retrieved yesterday.
Thanks again for all your efforts.
Marie Winn

Here's the reply: Received today 5/18/07 - around 1 pm

The eggs were not retrieved due to the adult sitting tight.(Last year they were not around when we collected them). We are not going to push a bird off if there is any possibility of a renest; although this might not be the case, that was our decision. Chris will try to collect the eggs a bit later.( I have been out in the field and was going to email you today. Due to the fact that you seem to have been in touch with Ward I thought he might have told you by now).

I do not have time to respond in full to your earlier lengthy email, since my job/time is to deal with endangered/threatened species, but I will reiterate that I feel from having seen the nest and cradle/pigeon spikes up close that neither have anything to do with the birds' failure, and that the fertility of the adults/ "conclusive answers " can not necessarily be judged/gotten based on the eggs alone. Unfortunately in some situations like this one, the point comes when it may be best to accept the fact that nature will take its course, whatever that may be. Again, we may never have all the answers, no matter how much money we spend on egg analysis.

We are not planning on being involved with any egg removals in future years at this site. Hopefully the pair at this site will produce at some time in the future.

Yesterday in the park and quick PS about the eggs

David Speiser, bird photographer extraordinary, sends photos of birds seen yesterday in Central Park, and writes:

Today was a slow migration day until I went to Sparrow Rocks in the afternoon. At least three Bay-breasted Warblers were present, as well as a beautiful male Blackburnian, Blackpoll, B&W, Magnolia , Black-throated Green and Red-eyed Vireo.

Red-eyed vireo [you can even see the red eye if you look closely.]

Blackpoll warbler
Blackburnian Warbler

Bay-breasted Warbler
Black and White Warbler
Also yesterday, I sent a note to Barbara Loucks at DEC asking for confirmation about the egg-removal. [ I haven't received a reply yet. [This is their busy season I'm sure.]

Nest guess

In regard to Eleanor Tauber's photo of a nest in the red part of a stoplight, [posted yesterday] Bill Trankle of Indianapolis, IN writes:

Marie, it's very difficult to tell, of course, but if I had to guess, I'd say the babies in the stop-light nest are robins. Most of what drives that assumption is the nest construction, which is way too neat for starlings (at least the ones that used to nest in my soffits!). I've seen zebra doves do the same thing back home in Honolulu. I don't know how they handle the constant "light on, light off," but they seem to ignore it quite well!

PS from Marie: Yes, I think Bill is right. I hope Eleanor checks on the nest and confirms in a few days.

Thursday, May 17, 2007

Flash - egg news

Lola on nest yesterday, 5/16, eating dinner
The note I received last week from Barbara Loucks at the DEC began:
    Yes, we will be collecting the eggs this Wednesday. We have a very busy day planned but will squeeze it in in the am.

. I was at the model-boat pond at 7:30 a.m. yesterday, thinking I might catch a sight of the DEC team scooping up the eggs. But I saw Lola sitting peacefully, and no sign of action. Perhaps it's too early , I thought and so went on with warbler-watching.

But it doesn't look like it happened, based on photos posted today on, with Pale Male & Lola carrying on normally on the nest.Perhaps the rainstorm interfered with the DEC's schedule yesterday

I'll keep you posted as soon as there is any news.

More warbler photos from Liliana's papa

Blackburnian Warbler

Black-throated Blue Warbler

Chestnut-sided Warbler

Common Yellowthroat [aka El bandito]
All photos above, by David Speiser, were taken yesterday, May 16, 2007, in Central Park.

Wednesday, May 16, 2007

An urban nest

Eleanor Tauber writes:

I saw this nest in the red part of a street lamp yesterday while doing Starr Saphir's walk in the North end.


Marie writes:

Thanks for sending, Eleanor. If these are starlings, I'm glad they haven't taken over a flicker's or red-bellied woodpecker's nest , as they often do.

Will the hawks keep sitting? Blakeman answers

I asked in my previous post:
I'm assuming they [Pale Male & Lola, once the eggs are retrieved] won't continue to sit without eggs in the nest, but I'll check with John Blakeman to see if that's correct.

John Blakeman replied:
Correct. Without the light-colored objects in the nest the birds will not incubate. There won't be anything to incubate.

If a bird settles down and appears to incubate, this should last for just a few minutes, merely a continuation of habit.

But in all likelihood there will be no more sitting for the year.

And it won't hurt the pair at all. They won't have any pondered lamentations about the "loss" of the eggs. Life will go on very well for the birds. No one should take concern about any emotional implications of the eggs' retrieval.

I'm glad that the eggs will be examined again this year, perhaps with more definitive results.

--John Blakeman

Hawks and smaller birds

Pale Male and Lola on nest yesterday - 5/15/07
Photo courtesy of
Today is the day the eggs are scheduled to be retrievedby Chris Nadareski of DEC. It's good to know that our favorite hawks won't have to sit futilely in heat or rain for much longer now. I'm assuming they won't continue to sit without eggs in the nest, but I'll check with John Blakeman to see if that's correct.

Migration news:

Yesterday and today were and are peak migration days. Birds everywhere -- orioles, tangers, warblers, vireos, thrushes throughout the park, many of them singing.
Below, a photo of yesterday's stars, which stayed on and were seen by many this morning--Bay-breasted Warblers. Then one birder's list of birds seen yesterday and reported to e-birds.

Photo by David Speiser - 5/15/07

From e-birds

Site: Turtle Pond, Ramble
Date: Tuesday, 5/15/07
Reported by: Pat Pollock

Bay-breasted Warblers - in and around Locust Grove &
in Ramble - many observers
Cape May - SE end T. Pond
Blackburnian W's - bathing rock above Azalia Pond,
another one T. Pond
Prairie W. - Polish Statue late 3:30pm
Hooded W. - between Tupelo, bathing rock+
Chestnut-sided W's
Canada W.
Magnolia W's
Black-throated Blue W's
No. Parulas
Black& White W.
Wilson's W. - near Oven/ bamboo
Common Yellowthroats
Yellow-rumped W.'s
Canada W.
Great Crested Flycatcher - no. of Pt. bench on hill
Pewee - Tupelo & Polish Statue
Rose-breasted Grosbeak - T. Pond SE
Red-eyed Vireos
Swainson's Thrush
Baltimore Orioles
Scarlet Tanager
Wood Thrushes

Monday, May 14, 2007

Queens Hawkcam fxed

The Queens nestlings as of May 8, 2007

Those of you who have become addicted to the Queens Hawkcam run by the New York City Audubon and Jeff Kollbrunner, good news. You've probably been having withdrawal symptoms since the site went down a few days ago. Now Jeff writes:

I was able to correct the issue with the Hawkcam and it's back on-line since about 10am this morning!! Maybe you would be kind enough to post a small note that it's back on-line since there were many of your readers that were regularly enjoying the Hawkcam until it went down late last Thursday.

OK fellow addicts, you can click below for your fix of this wonderful webcam, or, if you haven't seen it yet, click to become totally addicted: