Nesting season is here

Baltimore Oriole in Central Park -- an annual nester
Photo by Cal Vornberger

A look at Jack Meyer's list of birds seen today [see below] gives a good idea of Central Park's nesting birds. Birds known to nest in the park in past years are marked with an asterisk. Possible nesters are marked with a question mark. Missing from Jack's list, but usual Central Park nesters, are: Mourning Dove, Red-bellied Woodpecker, Downy Woodpecker, Northern Flicker, American Crow, Tufted Titmouse, White-breasted Nuthatch, Northern Mockingbird, Cedar Waxwing, and Song Sparrow [near the Ladies Pavillion, most years]

Site = Central Park
date = 6/14/08
observers = Jack Meyer

Double-crested Cormorant (Lake)
*Green Heron (Azalea Pond)
Black-crowned Night-Heron (Lake shore, 2)
*Mallard
*Rock Pigeon
Eastern Wood-Pewee (Heard, ramble)
*Eastern Kingbird (Turtle Pond)
*Blue Jay
?Tree Swallow (Over lake, early AM)
?Northern Rough-winged Swallow (Over Lake, a few early AM)
?Barn Swallow (Over Lake, several)
*House Wren (Heard, west of Shakespeare Garden)
*Wood Thrush (Ramble, on nest)
*American Robin
*Gray Catbird
*European Starling
Chipping Sparrow (Maintenance Field)
*Northern Cardinal
*Red-winged Blackbird
*Common Grackle
*Baltimore Oriole (West of Shakespeare Garden)
*House Sparrow

Note from MW: Every year a wood pewee is heard singing in the park until mid-June, leading to the idea that it must nest in the park. But no sign of a nest, or fledgling young has ever been found.

A quick report

Since I've been sharing info about my work in progress over the years, I'll quickly catch you up with what's going on as my new book is about to come out. Of course you never know where the slings and arrows of outrageous fortune are going to come from, but so far so good. There have been a couple of reviews out already, a REALLY nice one in OneEarth Magazine [published by the Natural Resources Defense Fund.] And there'll be something in the NY Times Book Review on Sunday 6/22 -- that's the scary one.

These days have been wildly busy-- with walks in the park with reporters for various papers and one for an NPR segment. And I'm also busy learning Powerpoint for the Natural History Museum presentation next Tuesday. Thank God an 11-year-old relative came over and helped me the other afternoon.

That's it about me. Here's unencouraging news Pale Male:

I spoke with Glenn Phillips at the NYC Audubon day before yesterday and learned that the while NYCA had managed to get permits for retrieving the eggs from the Fifth Ave. nest, the window washers were NOT willing to go that near the nest and declined to retrieve them.

I do believe we cannot fault Audubon for this! I am convinced that they've been acting in good faith. NYCA is an organization that has long worked for the well-being of our urban birds and their habitats, and I have worked with them many times on various issues. They don't deserve to be whipping boys for this unhappy story.

You can imagine that I get lots and lots of mail about this. Some of it is very angry. But I feel obliged to repeat that anger directed to anyone other than the management of 927 Fifth Avenue, who chose to remove the nest in 2004, is misplaced. And even that anger might be tempered by the knowledge that the powers-that-be at 927 Fifth acted in good faith too, [after acknowledging their mistake,] and the building invested time and much money to try to restore the ledge as a nesting place for the hawks.

James rescues a young peregrine

Photo of Peregrine Falcon fledgling by James O'Brien

James O'Brien is a young birdwatcher who pays special attention to the hawks and falcons in less prominent parts of the city than Fifth Avenue. On the birdwatcher listserv eBirds he often provides a round-up of raptor action in other boroughs of New York City, especially the Bronx. In the latest posting on his blog http://www.yojimbot.blogspot.com
he describes the rescue of a newly-fledged Pergrine Falcon. Click on the link to get the whole dramatic story.



PS More to come soon on the Pale Male's eggs story

More on Pale Male and Lola's eggs: Glenn Phillips's question, and John Blakeman's answer

December 7, 2004--the day Pale Male's nest was removed
Photo courtesy of PaleMale.com

Note received from Glenn Phillips, executive director of the NYC Audubon:
Marie -   I've gotten a number of comments from people who seem to think that courtship and copulation are connected in some way to fertility. EVERY scientist I've talked to - some of the most respected names in ornithology - have told me that there is no correlation. (One notable non-raptor example:  vasectomized Canada Geese males will defend territory, court and copulate... But there were many similar cases - of course no one gave a vasectomy to a raptor, but known infertile males routinely courted and copulated.) I was wondering if you had some source for information that contradicts what these folks have told me....   -Glenn


My reaction to Glenn's letter is this:

The issue here is not whether infertile male hawks can still copulate. The evidence of the vasectomized hawks clearly demonstrates that there is no correlation here. In the case of Pale Male's nest failures, making this seem like the primary question is a red herring.

The issue is whether a healthy hawk who has had ten successful nest outcomes and who is showing no signs whatsoever of bad health or diminished vigor [as evidenced by normal copulation behavior] can be judged to be INFERTILE BECAUSE HE IS TOO OLD when his nesting effort fails during the 11th season.

A more important question to ask would be whether there is any evidence to show that a hawk's fertility decreases as he ages. As you'll see below, [in the note by John Blakeman] there is some evidence showing that it does not.

Meanwhile, if one major change to Pale Male's nest structure occurred at the start of that 11th season,  isn't it far more likely that the failure can be attributed to that change [the stainless steel cradle] rather than to the sudden onset of age-related infertility?

This is why it is so important to retrieve the eggs and ascertain whether they were properly fertilized. Only that would set the issue to rest.

 John Blakeman notes, on that subject:

Infertile birds can and do copulate. Copulation, per se, does not assure or indicate absolute fertility .Fertility depends upon the quality of the involved gametes, the eggs or sperm cells, not the presence or frequency of the sex act.

But if Pale Male’s gametes are somehow now defective or insufficient, he is likely to express other, concomitant behavioral or physiological problems. He shows none.
A seminal (good word) question asks if more aged raptors can produce ample gametes, or does gamete quality or viability decline with advanced (but otherwise healthy) age? I believe that the record from captive raptor breeding indicates that viable sperm is produced throughout a tiercel’s life, that gamete viability remains throughout life.

In the case of the 927 pair, just what are the chances that sperm viability happened to decline in the years immediately following the installation of the nest support cradle? Is it mere happenstance that sperm quality, and therefore reproduction, coincidentally terminated during the year of the cradle’s installation?

Actually, that question is moot. The only real question of significance that remains is, were this year’s eggs haploid or diploid. If haploid, [unfertilized] the reproductive future of the 927 pair can be written off. If diploid, causes for hatching failure need to be further pursued.
 
A definitive answer, positive or negative, will allow a more rational public nderstanding of what might be seen up there next breeding season. If the eggs are unfertilized, the only answer would be that Pale Male’s gametes aren't up to the task anymore. His reproductive years are behind him
 
But if the eggs were diploid, [fertilized] there can remain the hope that future hatchings and fledgings might yet occur at 927 Fifth Ave.  John Blakeman