Friday, November 24, 2006

Better than "doing it."

Pale Male & Lola in courtship mode
Photo by Lincoln Karim - November 20, 2006

Dear Marie,

Now that courtship seems to be in the air, I offer another euphemism for the ultimate act. I was recently reading an article about Darwin which contained a quote from an observation he made about a female bird “accepting the attentions” of a male who seemed attractive to her as the father of her future progeny. So maybe someone will want to report when Lola begins accepting Pale Male’s attentions. Personally, I like “a ruffling of the feathers” (Trollope), better.

Eleanor MacDonald

PS from Marie: Eleanor is a long time Central Park hawkwatcher, and also a Riverside Park hawkwatcher. She lives a block away from me, and we often exchange notes about our West Side redtails.

Thursday, November 23, 2006

Happy hopes for Thanksgiving

Lola and her first chicks - April, 2002
Photo by Lincoln Karim

First a note from a regular website correspondent responding to my posting of Nov. 21. Then a response from John Blakeman to the same photo.

Dear Marie,

Mating season is exactly what I thought when I saw Lincoln’s photos. Holy cow! Is it that time again? Hope springs eternal and I cannot help but want to grab your book Red Tails In Love and grab my Pale Male DVD and dive in again. I can almost feel my heart racing thinking that we may see another brood of chicks. Wouldn’t it be wonderful? It makes the tough New England winter bearable. Hope you are well. Always enjoy your web site’s dialogue, I learn so much.

Best Regards,

Nan Holmes

And from John Blakeman:

Yes, Lincoln's photos of the pair with descended legs is absolutely the very first sexual expression of the coming breeding season. The birds have experienced marked reduction in day length, and this photoperiod change moderately bumps their pituitary glands into action. A very slight elevation of breeding hormones has been released.

With abundant food, Pale Male and Lola don't have to spend most of their waking hours searching for the next meal, as our rural red-tails must do at this time of the year. The Manhattan red-tails have the physiological freedom to allow themselves to respond to the slightly increased sexual prompts the hormones are allowing. Out here in rural Ohio, my wild hawks must concentrate solely on finding food. We don't see any sexual foot-dragging at this time of the year. Pale Male and Lola, however, can wonderfully digress into initial procreative activities. No red-tails anywhere live better than they do.

--John Blakeman

Wednesday, November 22, 2006

An exciting discovery by Central Park birdwatcher

The nest, under the airconditioner

The location
Photos by Rebekah Creshkoff

Rebekah Creshkoff is one of my oldest Central Park friends. No, no, I don't mean that she's old -- she's actually a young woman. I mean I've known her a long, long time, ever since I started coming to the park regularly. That was probably around 1990.

She's a great birder, and a very good observer of the world around her. I'm not surprised that she made this remarkable discovery. Here's her letter that arrived on November 19, 2006

Marie, I discovered a Monk Parakeet nest this morning. They are building beneath an air conditioner on the top floor of a 6-story building at the NW corner of 103rd and Amsterdam. Is this a Manhattan first?

At about 9:45 am this morning, I was biking up Amsterdam when I heard a parrot-like noise. It didn't sound anxious (as a cockatiel owner, I'm familiar with what anxious parrots sound like). I looked and quickly spotted a Monk Parakeet perched on the railing of a fire escape of the building described above.

After a few moments, it flew east, where a pedestrian mall leads into the grounds of the Frederick Douglass housing project, where there are a number of of mature London Planes. I lost track of the bird, then spotted it in the trees, lost track again... then a 2nd bird flew overhead, W to E, and also landed in the Planes. Then I saw one of the birds fly W with a long twig trailing from its beak. That's when I tracked it to the air conditioner.

I took several pictures using a digital zoom, but the attached (the best of the bunch) reflects some camera shake. Went back a half-hour ago equipped with a better camera plus good advice from Lenny, [Rebekah's husband -MW] but the birds weren't home.

Tuesday, November 21, 2006

No the eggs didn't get fried: one more comment

Pale Male and Lola, Sat, Nov 20, 2006
Photo by Lincoln Karim Http://
[Soaring with talons extended -- looks like courtship is beginning for the 2007 season]

Bill Trankle of Indianapolis adds a comment:

Marie, while I'm not a physicist, and my recollection of circuits is sketchy, I'm guessing that current is irrelevant when it comes to the issue of egg viability. While Ms. Kolling has a good point about bulk concrete (or is that limestone facing?) being a poor conductor, I think that the high humidity in the spring and summer months probably deposits enough surface moisture on the stone to dissipate any voltage that might accrue on the cradle. The moisture doesn't have to be visible, but it's there, and with the amount of voltage being minuscule it would be more than enough. Also, remember that egg shells are about 95 % CaCO3--the same stuff of which limestone and concrete are largely composed, so, while not effective for insulating against large currents due to their thinness, the shells themselves could insulate the embryos from the microcurrent present (additionally, any moisture on the shells might actually create a Faraday cage around the contents, further protecting them!). That last part is a bit of a stretch, but maybe we can get someone knowledgeable about EM fields to write in about it!

As always, I enjoy the discussions.
Bill Trankle

Monday, November 20, 2006

PS: Electrified cradle hypothesis

Karen Anne Kolling adds a comment to the "what happened to the eggs" mystery discussed in today's earlier post:

The current flow would have been in microvolts, and it would have grounded out to the building to which the structure was attached, I believe. I can't see how there could have been a current flowing through an egg, even if it were touching one of the metal prongs.

It's been a long time since I've been in school, but I don't think anything is going to ground through what looks like concrete, which is a pretty poor conductor.

Back to the Pale Male mystery: metallurgy

Photo: Lincoln Karim -- 2005

I had an interesting conversation at dinner at a friend's house on Saturday. It led me to write John Blakeman who, as ever, promptly responded. Here 's the correspondence:


At dinner last night someone who seemed rather knowledgable was speculating about the Pale Male nest failure, and my idea that the new "cradle" is likely to have been a cause. He introduced an idea new to me: that the steel structure, combined with other metal materials that might be in parts of the cradle--screws, bolts, etc., would combine to become some sort of battery -- and create electromagnetic effects of some sort.
It sounds far out, and I'm probably not presenting the guy's idea accurately. Indeed. I didn't understand it much at the time. But I wondered if this might stimulate any ideas.


The fellow who proposed the "metal effects" remembers his college chemistry or engineering classes. There is no doubt that corrosive chemical reactions involving the "mutes," the falconry name for hawk droppings, would be electrochemical in the new nest structure, which was constructed of at least two different metals (which is required for corrosive electrochemical reactions). As the person knows, it is crucial that the two different metals be in direct contact with each other and that they must be wetted. Such reactions are said to be "galvanic," and yes, they will produce small electrical currents through the metals.

But I seriously doubt that these charges would have been sufficient to cause any egg abnormalities. The current flow would have been in microvolts, and it would have grounded out to the building to which the structure was attached, I believe. I can't see how there could have been a current flowing through an egg, even if it were touching one of the metal prongs.

If galvanic reactions between two metals and the mutes were serious, the one of the metals will be slowly sacrificed in the corrosion. Something will fall off someday. The structure will corrode, the same thing that happened to the Statue of Liberty, causing it to be rebuilt a number of years ago. There, instead of hawk mutes, the offending liquid was salt spray that caused galvanic reactions between the copper cladding of the statue and the interior iron support skeleton. But that took over a century to be significant.

For the Pale Male nest, good thinking, however. Something else, perhaps just as anomalous, was at fault.

--John Blakeman