Saturday, February 02, 2008

NYC Audubon's statement

For those of you not on the NYC Audubon mailing list, here's the statement they mailed out today:

Pale Male & Lola get a helping hand from NYC Audubon
removing pigeon spikes from the nest
removing pigeon spikes from the nest

Spring spruce-up came early for Pale Male and Lola, the red-tailed hawk pair nesting on the façade of 927 Fifth Avenue. On January 29th, scaffold workers, directed by New York City Audubon, made adjustments to the nest cradle mounted atop a 12th floor cornice of the building. Although the work done required only a few hours, it could be critical to the birds’ ability to produce chicks this spring and in the years to come.

The beloved red-tailed hawk pair, have had no success breeding chicks since re-establishing their nest on the cradle in spring 2005. Prior to that date Pale Male and his mate produced chicks each year from 1995 through 2004 – a total of 26 hatchlings, of which 19 survived to fledge – making Pale Male one of the most successful red-tailed hawks ever documented. Concerned by the correlation of lack of propagation and construction of the cradle, NYC Audubon enlisted four red-tailed hawk experts around the country to study the situation and present conclusions.

At the panel’s request, NYC Audubon arranged for two wildlife photographers, Jeff Kollbrunner and Donegal Browne, to take photos of the interior of the nest from the building’s roof. Those Jan. 4 pictures showed that stainless steel pigeon spikes extend above the nest material, posing a serious threat to successful embryo development during the 5-6 week egg incubation period. Birds must roll their eggs so that fluids within the egg are gently distributed and the tissues don’t stick together and form a dense mass. The erect spikes appear to impede this critical step and also to interfere with the hen’s ability to make proper contact of the eggs to her brood patch, keeping the eggs consistently warm. An observer reported that the hen’s brood patch appeared to be rubbed raw this past nesting season.

Braced with that evidence and the panel’s recommendation to remove the spikes beneath the nest bowl, NYC Audubon worked with various city authorities and the building’s coop board to obtain permission to remove the spikes from the nest cradle. NYC Audubon is especially grateful to Parks Commissioner Adrian Benepe, who helped obtain needed permits, and to board member Sandy Fiebelkorn, who worked tirelessly for months to coordinate the whole process. The task was time-critical; early February marks the start of copulation.

There is no guarantee that this improvement of the birds’ habitat will mean chicks in mid-April, as the recent lack of reproductive success may have other causes. However, as one NYC Parks & Recreation official said, “I’m hawkish about what we’re doing.”

for more photos visit

Friday, February 01, 2008

Another nest question and an answer from Blakeman

Protesting the nest removal--December 2003
[Don't forget that the protest, too, was sponsored by the NYC Audubon!]

Bill Trankle of Indianapolis writes:

Marie, I can't help but be excited about the prospects for our red-tails this year, especially after seeing the photos and John Blakeman's analysis. It looks to me from the photos of the workers on the scissor jack (and shame on the guy with no helmet--OSHA would fine him for that!) that the two guys doing the work are using bolt cutters to take the spikes out. I'm assuming (and crossing my fingers) that they snipped the spikes off at a low enough level not to interfere with anything, but I'm wondering if their doing so as affected the nest construction at all. John has repeatedly explained that the red-tails don't just dump sticks in a pile and call it a nest, but instead they weave them together to form a tight bundle that will be sound enough to cradle their precious cargo. While the workers left everything up there, could their loosening the pile have any impact, and how will PM and Lola deal with it (if they can)?

Keeping everything I have crossed!

Take no concern. The moderate nest displacements resulting from the prong snipping was equal to what happens to un-occupied tree nests in wind storms. Yes, when Pale Male and Lola get back on the nest and begin to seriously prepare for new eggs, they will find things a bit out of place. But no more so than what happens naturally in typical forest tree nests in the off season. They will diligently get things back in proper order.
Had the exterior rim of sticks been removed, nest reoccupation or refurbishment could have been in jeopardy. But the big sticks or twigs are still there, in place. The birds will get everything in proper order, by instinct. The fact that Pale Male went right to the nest after the swing stage was taken away indicates that all is well. He not only flew over there to look around, he got down into the nest itself.
I'm pleased with the way the nest was left by the workmen -- and so was Pale Male. Just a matter of time, now.
--John Blakeman

Thursday, January 31, 2008

A perfect thank you

For all who weren't around at the beginning, or who don't know how to express their thanks, I'm reprinting Bruce Yolton's summary and thanks from his website--my sentiments exactly.

Pale Male and Lola's Nest - January 30, 2008

On Tuesday, NYC Audubon refurbished the nest at 927 Fifth Avenue. 72 pigeon spikes were removed, as well as three eggs. After three unsuccessful years, Pale Male and Lola will have a much better chance of having a successful nesting season this Spring.

I have the highest respect for the staff and board members of NYC Audubon, who undertook this project. The refurbishment required research and consultation with scientific experts, getting permission to modify the nest from the Co-Op board and government officials, and extensive and expensive technical planning and execution.

NYC Audubon usually focuses on education and conservation activities in New York City. To have focused on such a specific issue must have caused lots of discussion at board meetings. Kudos to Executive Director, Glenn Phillips, for having the courage to take on this important issue.

NYC Audubon is in the midst of its Annual Appeal for 2008. I encourage everyone to make a donation to NYC Audubon to thank them for helping Pale Male and Lola.

Thank you

Photo to think about while crossing fingers

It's time for thank yous to the NYC Audubon, for undertaking and carrying off this difficult job, in the midst of much anxiety and suspicion

and to John Blakeman, special friend to the Fifth Avenue Hawks since Day 2 of the nest-removal crisis, for the important work he did as one of the experts consulted


for the explanations and clarifications he so generously offers to readers of this website, and others.

Wednesday, January 30, 2008

What did the workmen leave? Q & A--Blakeman

Ciro Monaco Jr. asks:

Regarding the nest spike removal, I have to ask whether the workers left the nesting material up there. I'm no expert and maybe this isn't the case, but it would seem removing the material would be a setback as Pale Male and Lola would again have to work endlessly to rebuild the nest and this would deplete their energy stores. Just wondering if you knew the answer.

John Blakeman answers:

Ciro's concerns are well thought out, and need to be addressed.
First, the lining material in the nest was not removed or discarded. That was a specific instruction in my recommendations for operations at the nest. So large amounts of new lining materials will not have to be flown up to the nest.
But interestingly, in wild rural nests, old nests must be almost completely rebuilt each year, with a near-complete replacement of the old soggy or blown-away lining materials. In the 927 nest, the old lining materials were actually held in place by the spikes, as the photos show. So naturally, the hawks are physically and behaviorally adapted to bring up fist-fulls of new lining materials.
Being the big, broadwinged birds they are, Red-tails can easily play on even the most modest winds to effortlessly lift a few grams of new lining up to the nest. Instead of being a complication or detriment, nest construction or in this case, refurbishment, has very positive behavioral outcomes for the hawks. To be anthropogenic, all of this will just like the selection and moving a young couple's new furniture into an NYC apartment. Yes, it will be work, but exciting, rewarding work at that.
All of the hawks' activities at the nest in the coming weeks will be positive, setting things up for real incubation and hatching.
--John Blakeman


Blakeman illuminates the spike situation - Post #3

Photo by Donna Browne - enlarged detail (showing spikes) of Blakeman's red-dotted photo below

This morning I e-mailed John Blakeman and asked him the following question (referring to Donna Browne's photos I had posted earlier in the day:) John: Is there any way to explain (specifically if possible) what there is about these photos that indicates the problem that the spikes posed to the eggs? I'm sure readers would like to have this illuminated.

Blakeman's response, along with the photo below:

The attached photo indicates the problem with the pigeon spikes. It was taken by Donna Browne in early January. I entered the photo on my CAD program, zoomed in, and placed a red dot over each of the visible spike tips. Without this magnification and spike marking, there doesn't seem to be much of a problem.
But it was this marked photo, I believe, that sealed the necessity of getting up to the nest and removing the spikes, at least the ones directly in the center of the nest, in the lined nest bowl, where the eggs are incubated.
The red dot just to the left of the left-most egg is revealing. Not only is the prong sticking up into the space where the eggs would have been rolled (impossible because of all the protruding metal spikes), but the closest magnification (here obscured by the added red dot) reveals that the spike shaft actually extends directly to the right, under the egg. The egg is actually wedged or perched right upon this metal spike's shaft.
The red dot immediately to the right of the eggs also appears to mark a spike that bends back, directly under the eggs.
Actually, there were almost surely many more spikes slightly buried under the lining material, which probably expanded during summer rains and wind events. Back in March, when the eggs were laid, it is very clear to those of us who have seen Red-tail eggs and nests that the prongs both prevented proper rolling (a crucial factor in egg hatching) and they also directly touched the resting eggs, wicking away incubation heat to the metal cradle frame and screening below.
Both of these now-obvious factors, the eggs resting on the spike shafts, and the fact that the spikes extended up above the nest lining, thereby precluding proper rolling, virtually assured incubation failure.
Once again, there are three essential factors in successful hawk egg incubation. One, humidity and moisture loss from the porous eggshell, was not a factor. Lola's naked brood patch took care of that factor. But keeping the eggs at sufficient, enduring temperature, and properly and frequently rolling them, were both impossible with the spikes extending into the egg space, as I previously contended for a year or more.
Now, with the spikes in the central bowl gone, the eggs will not be a few degrees too cold in cool March nights way up there above Fifth Ave. And when Lola feels a compunction to roll the eggs of her developing children, she will be able to do that naturally and instinctively. She will be able to push an egg outward, spin it around, and then nudge it back into place under her brood patch. Before, the spikes absolutely prevented that.
Again, in summary, originally the eggs became lodged between the spike shafts down in the lining, thereby precluding proper rolling and temperature maintenance.
Now, I think we have a great chance of seeing eyasses once again take to the skies above Central Park. Let everyone rejoice when that happens!
--John A. Blakeman

Blakeman comments on the nest-fixing project

The large dark spots on the backs of the hard hats were a suggestion of mine. They are made to look like two large eyes peering back into the sky.
When at a nest, Red-tails will often dive at a human interloper, occasionally even striking the person on the back of the head, shoulders, or middle of the back. But if the person turns around and looks at the attacking hawk, the bird turns away, knowing that the interloper sees that hawk and will defend himself.
Fortunately, there apparently were no aerial attacks from Lola or Pale Male. The eyespots on the hard hats may have helped prevent such flights. The last thing anyone would have wanted would have a technician getting a multitude of 2-inch needle-sharp talons embedded in his scalp. Our birds had the good sense, perhaps prompted by the suggested eyespots, to remain remote and distant.
Had the spike removal waited just a few more days, the hawks could have been far more defensive. As observers of this pair surely have noted over the years, activity at the nest really begins in earnest in February. The birds are detecting increasing periods of light each day now, and that starts the breeding and nesting hormones flowing.
Let everyone be assured that the nest will now be refurbished by the pair in the usual and typical manner of mature Red-tail pairs. The birds won't even know that the spikes are removed. Things will go on just normally now, with no loss of incubation heat, and equally important, with proper egg rolling.
And the removal of the old eggs, as I've indicated to Donna Browne, is also a very helpful development. In wild Red-tail nests, old, unhatched eggs virtually never survive an entire year in the nest. Raccoons eat them, or they just rot and blow out of a less stable tree nest. With the eggs up there now, Lola would have been impelled to begin to sit on them, quite prematurely. Of course, she will naturally spend extensive periods of time sitting on the empty nest. But without the old eggs up there, those periods of bare-nest sitting will be reduced and will not impede normal get-ready-for-eggs preparations, whether physiological (hunt to get nutrients to make eggs), psychological (be available for frequent sex-inducing flights and copulations), and finally, thermal and structural determinations, (to affirm nest construction suitabilities).
I'm so pleased to learn that this crucial project went forward and came to some useful completion -- just in time, too. I commend everyone who brought all of this together, especially the people at NYC Audubon. It's one thing to educate the public on natural resources and conservation problems, which Audubon intelligently does. But it's another matter to step forward, commit institution resources, and actually get things done. Words can be cheap. Rectifying difficult conservation issues can be expensive, as this surely was. Perhaps readers should personally commend NYC Audubon for their foresight and execution of this extremely difficult program. Well done, all.
Like everyone, I look forward to seeing more photos of the completed spike removal.

John A. Blakeman

Working on the nest

Donna Browne sent me three photos of work being done at Pale Male & Lola's nest. Now you don't have to take my word for it.

Last year's eggs, now at Ward Stone's pathology lab in Albany

Working on the spikes

I'm a little worried about the guy at the left in photo #3. Where's his helmet?? I don't imagine the hawks were happy to see human activity at their nest, little knowing it was going to help them out. And as we know, their talons are deadly weapons. I'm not sure when these pix were taken. But I'm not asking any questions. Just posting everything immediately.

PS Keep your eye on Donna Browne's site
I understand that she will be posting more pictures and info from an insider point of view.

Tuesday, January 29, 2008


Just received this news via e-mail

Date: Tue, 29 Jan 2008 13:30:33 -0800 (PST)
From: lynn rollins
Subject: Re: Pale Male nestwork

Mission completed. Nest has been spring cleaned of almost 72 spikes(I would like to see all of us try to turn an egg without getting impaled). Three eggs were retrieved which will be sent to Ward Stone...they are still heavy so that makes it more interesting.
The Mission was photographed and video taped. Pale Male made a nest stop while the engineer was being brought up to make sure everything was properly done and we hope he likes his new digs and brings his bride home to roost!
Hats off to Sandy for her work. It was quite a feat to organize all these people...and many thanks are due to people who helped make it go so smoothly.

What does this mean?

1. The work on removing the spikes from the base of the cradle where Pale Male and Lola are nesting has been completed! The spikes were long considered a possible reason why the eggs haven't hatched for the last 3 seasons. Now let's hope they WERE the problem, because that problem no longer exists.

2. What are those 3 eggs? Those are the ones that didn't hatch last year and were never retrieved by DEC. They would have impeded the nesting process this year -- Pale and Lola would have had to work hard to remove them. Now they have been removed. Even better, they've been sent to Ward Stone, the wildlife pathologist of DEC in Albany. Perhaps he can still find material for analysis at this late date.

3. NOW, everybody, finger-crossing time.

And great thanks to the NYC Audubon and all the scientists who worked hard to make this valiant attempt at making the nest egg-worthy this year.