Thursday, May 17, 2007

Will Pale Male and Lola Double Clutch this Year?

Dusk, June 10, 2005. Charlotte and very young eyasses on the nest. The year she and Pale Male Jr. double clutched and were finally successful in their Trump Parc location. Earlier that season and for a number of seasons before that, their nests had failed because the eggs had rolled or were blown out of the nest. The nest surface has no protuberances with which twigs could be anchored and the twigs blew away faster than they could be gathered. At that height the wind and rain are extreme. That year Charlotte and Jr. did lay a second set of eggs in the nest after the first set disappeared. The late Spring and early Summer of 2005 were very dry and I believe that change in weather was key to the success for their second clutch of eggs staying put long enough to hatch.

Last night it occurred to me that since Pale Male Jr. and Charlotte had laid a second set of eggs, that perhaps Pale Male and Lola might decide to do the same thing after their current set is gone. (The DEC is going to remove this years failed eggs for testing, leaving Pale Male and Lola in much the same situation, no eggs, as Jr. and Charlotte were in 2005.) So off went an email to hawk savvy John Blakeman for his thoughts on the matter.


I seriously doubt that there would be a second clutch (double-clutching, in the terms of the raptor breeders). It's very, very late. They've been on the eggs for a long time, way past normal hatching.

The double-clutching of the other pair was completely unexpected by me. I don't know of any other double-clutching by red-tails, although it obviously occurs. Certainly it can only happen when there is ample prey, and that's the case in Central Park and probably all of the other new NYC red-tail territories. That's the very reason the birds are there.

Because the pair is older I think there is a reduced chance of any re-laying. A young female, as was Charlotte, is more capable of mobilizing a second round of calcium compounds from her bones for the eggs. I don't think older birds are as likely to do this.

Glad folks enjoyed the prairie grass landscape photos. Hope it prompts people to think beyond the castle greensward and golf course motifs.

--John Blakeman
Now I realize, as John Blakeman says, it's very late in the year for laying. And he's probably right as he most often is that there is some serious doubt that it could happen.
In fact the photo period may be so far off that they wouldn't even be cued to do it. But during their withdrawal from the nest back to the park in the last two failed years, they reversed the order of courtship. They play out all the stages of coming to the nest and go forward with them in reverse order. That's how they do it. Less time was spent on the nest, they copulated, they danced over the Model Boat Pond, Pale Male brought Lola presents, they brought twigs to the nest, and eventually curved back to where they had started, back to spending their daily lives centered in Central Park.
This year will be different. There will be no eggs in the bowl of the Fifth Avenue nest as there have been in past seasons as the birds begin to withdraw.
One day soon the eggs will be gone. The visual cue will not be those pale ovoid shapes but rather a gently curving nest bowl of twigs. That's a different cue altogether. For Charlotte and Jr. it meant coming round to the copulation stage again but not continuing courtship in reverse after all but rather, going back, revisiting the copulation stage, and producing a whole new set of eggs and hence, Big and Little, their first eyasses.
Maybe just maybe, might Pale Male and Lola do the same?
Maybe, yes.
Oh, no question Pale Male is certainly older than his probable son Junior, but he doesn't have to put the shells on the eggs himself, now does he? And from all reports, when Lola appeared back in 2002, she was a true spring chicken, her eyes hadn't even as yet completely turned dark. And as John Blakeman says, there is always plenty of prey in Central Park making the feeding of eyasses possible even late in the season. Pigeons do reproduce year round as do rats after all.
What if, just take a second to think about it, what if, there is a problem with the human devised contraption under the nest? Hypothetically speaking lets say, just hypothetically now, it radiates cold through the metal towards the eggs when the air or rain is chill. Perhaps, just lets say perhaps it does.
The change in weather as the season progresses may well have made all the difference in allowing Jr. and Charlotte to have their success. If Pale Male and Lola's failed attempts had something to do with cold, might a later set of eggs make all the difference in the world?
It might, it just might
You say it would take a miracle. It might, it very well might take a miracle.
But then again, we forget Pale Male is a miracle. He's the original urban Red-tail, who cruised into Central Park one day and not only decided to stay but managed to find a mate to share his ridiculous urban breeding scheme with him. People said, "Red-tails don't nest in New York City." Poppycock. They hadn't met Pale Male.
In fact Pale Male found four mates as the dangers of a human environment took them. He built nests in a tree, the back stop of a baseball field, and heaven knows where else, until he found a spot that worked, the eyebrow shaped cornice above a windown at 927 Fifth Avenue.
It's a building. People said,"Red-tails don't nest on buildings." That was a miracle too. It doesn't seem like one now, no, not with building nests all over the boroughs but that's because he showed them and us that it could be done. But it sure looked like one then. And it was. It was inexplicable. It was unbelievable. It was an unexplainable event. It truly was a miracle.
And there was a little group of people down on the Hawk Bench before it ever was the hawk bench, watching, just in case a miracle did happen, first one year, and again the next.
Then after persevering as he's done in all things, (Pale Male learns from experience after all), he got the nest to work, and raised family, after family, after family. Twenty three eyasses fledged from that cornice covered with pigeon spikes.
Anyone counting miracles? How many does that make now?
I've no doubt he still has a few more miracles left in that pocket of his that holds prey so we don't see it until it magically appears on the nest.
Will he and Lola lay another clutch and find success this year? Maybe, maybe they just might use one of those miracles for that.
Or perhaps the miracle would come with the removal of the human built contraption and the return of the tried and true pigeon spikes.
Only this time with a little bowl trimmed into the middle so it wouldn't take two years for enough twigs to layer above the spikes to protect them from abrasion or cold. For we too, can learn from experience. Plus a pile of twigs we've collected heaped on to help the nest on it's way. Maybe, just maybe that would be the miracle.
Whatever form it takes, there will be another miracle. This is Pale Male we're talking about. Just as Charles and Marie and James and the rest of the original hawk watchers waited, so will we now, without loosing heart, whatever the report on the eggs or whether or not he and Lola double clutch, or we have to somehow deal with 927 and get the contraption removed. For Pale Male's courage knows no bounds, his big heart still beats, he spreads his wings every single day and soars over New York City, the spirit, beauty, and brains of the wild personified--and yes, with miracles still in his pocket.
Donegal Browne


Anonymous said...

This was all sounding good until you got to modifying the pigeon spikes. We've already messed things up trying to create a nest site for them, if we have the chance let's go back to what we know eventually works, not something that might produce another long string of failed years.

Donegal Browne said...

Personally I don't take any of the credit in attempting to create a new nest site for Pale Male and Lola in the past. I was all for their being able to recreate their nest on their own with the original moorings. I'm usually completely against human intervention but you aren't suggesting that the carriage contraption be left up there are you?

I think the people who put it up should take it down if it's found to be an offending element.

As I said I'm usually against human intervention but like the hawks, humans can learn from their mistakes and sometimes even help wildlife out a little when done judiciously No DDT and the mass production of properly sized, located, and shaped bluebird houses have helped that species mightily. Prepared Peregrine nest sites have aided in bringing Peregrines into prey rich suitable urban environments and their numbers are slowly rising. We do know that each time that the Fifth Avenue nest has had to be started over from scratch by the birds that the nest has failed the following year and I believe if I remember correctly, the first time it took two years before it worked. It's been suggested that the problem lies in the fact that each "first year" there is a problem with the pigeon spikes not being covered either by enough twigs not to damage the eggs or the solidity of the nest site fools the birds into thinking the nest is more solid and insulated than it is.

I don't think either of the suggestions for "help" in overcoming the past massive human intrusion they've suffered were particularly intrusive in themselves.

Our observations told us that the birds possibly weren't able to collect what looked to be a sufficient number of twigs in one season for a snug enough nest in the artificial environment of Central Park. Hence making a mound of twigs available didn't seem like it would hurt. The birds could use some and save themselves a huge amount of work and calories or just chuck them out if they didn't like them. Anyone who's watched Pale Male and Lola's love of rearranging twigs behind each other's back knows how they do love to move twigs around. Lola on the other hand is not nearly as fond in helping to procure them as some other hens are.

Next lets look at the idea of trimming a small number of mid area spikes. Often in 2005, somewhat less so in 2006, and not at all as far as I could see in 2007, both hawks spent a good bit of time scratching within the bowl of the nest with their talons.

Long time hawk watchers didn't remember ever seeing them do that. It has been many years since the nest failures after all. I just couldn't fathom what was going up there. John Blakeman suggested that perhaps at times a spike was poking up through the nest lining as would sometimes happen with a live twig growing from the tree on which a nest was situated. And what a hawk would do with a live twig in the same situation, these birds might be doing with a pigeon spike. They'd scrape at it until it broke off and wasn't poking them in the brood patch anymore or possibly abraiding the eggs.
Unfortunately pigeon spikes don't break off under the pressure of bird feet. In fact some have theorized that the nest doesn't succeed until there is enough weight from the twigs to bend the pigeon spikes over keeping them from protruding up.

Nipping the tops off the spikes that were in the exact position of the bowl site might, just might give a slightly higher possibility for success in the first, always a failure, year without doing any harm.

I'm throwing the thought out there for discussion, for reasons both pro and con, as there may well be things I haven't thought of.

When Bluebirds were attempting to use other kinds of birdhouses, after humans had decimated the birds native nesting cavities, it was 99% sure that the entry holes were just a touch too large and were allowing predation of the bluebird nests that slightly larger birds were able to fend off. Did people say, the birds chose those houses, some years they loose their clutch and some years they don't. Leave them alone. No they observed and they discussed and they measured. Then they made houses with just a slightly smaller hole. Just a little tweak made all the difference between failure and success.