Hawk questions

The Riverside Park nest, fallen, two days after 3 chicks found dead - May 13, 2008
Photo by Bruce Yolton - http://urbanhawks.blogs.com

While many Red-tailed Hawk nests in New York City have thrived this spring,, the two nearest to Central Park have had unfortunate outcomes. As most of you know by now, the three nestlings in the Riverside Park nest, so welcomed by all of us and closely watched by an eager group of hawkwatchers,  came to an unhappy end. First one, and then the other two were found dead on May 11, and the bodies were taken to Ward Stone at the DEC's Wildlife Pathology Lab near Albany.

Since there was a severe rainstorm lasting most of the day on Friday, May 9th, and the nestlings were no longer seen on Saturday, the first thought was that the deaths were the result of  hypothermia.  The nest was inundated, and the chicks died of exposure. John Blakeman gave his reason for this assumption in a posting here last week.

Ward Stone's preliminary examination found hemorrhaging of the lungs in all three nestlings.  This could have been caused by the anticoagulant chemical  found in many commonly-used rat poisons. We'll know if the young hawks ingested a toxic substance once the toxicology report is in . This usually takes a few weeks. BUT I don't know whether lung hemorrhaging is also a symptom of hypothermia, and whether that might still turn out to be the cause. I have a call in to Ward Stone to try to answer that question. In the meanwhile, it is too soon to jump to conclusions about whether the young were poisoned or died of more natural causes.

As for Pale Male and Lola, everyone in the world now knows that the eggs didn't hatch for the 4th time in a row since the nest was removed on December 7, 2004.  A reader of this site, Hank Riley, has written in a reminder that I am also forwarding to Glenn Phillips at the NYC Audubon:

May 15, 2008

Dear Marie, . .   
I'm waiting with bated breath to hear if any plans are being prepared for Pale Male/Lola egg retrieval and timely fertility testing  I'm not sure with Pale Male still visiting the nest, but maybe this year it will be possible to get the eggs a little earlier than in years before.  If that could be done it could answer, or whittle  down the list of possible explanations, the question of why the  eggs have failed this many years in succession.  I'm hoping that the wheels behind the scenes are turning, and that when it is appropriate, an announcement will be made that a plan has been developed to retrieve the eggs in time this year.  As you yourself said in March:  "All we can do is keep our fingers crossed now. And if there's a  failure, we must really make sure that the eggs are retrieved and  analyzed quickly, not for rat poison traces, (that's never been  an issue!) but for fertilization."

Yesterday's birder magnet and more warblers by David

Remember Liliana? Here she is in her birdwatching uniform, thinking about all the birds her Daddy, David Speiser, photographed in Central Park this week.

First: yesterday's birder magnet
Chuck-will's-widow [asleep]
Photo by David Speiser - May 14, 2008

A Chuck-will's -widow, a bird in the goatsucker family closely related to the Whip-poor-will, was discovered sleeping on a horizontal branch at The Point.

The Whip-poor-will's famous song has three syllables and resembles its name. The Chuck-will's-widow's has four syllables, also resembling its name. Both bird's are nocturnal, only seen when some sharp-eyed birder spots one sleeping on a branch during the day. Then the birding community comes a'running, as they did with this one yesterday. Especially well-represented were the photographers, among them David Speiser, who took the thrilling photo above.


Other birds of the last few days, also photographed by David Speiser:


Canada Warbler

Wilson's Warbler



Overnbird


Northern Waterthrush

Cape May Warbler

Chestnut-sided Warbler

Tomorrow: More about the Riverside Hawks, and a progress [or lack of progress] report about Pale Male and Lola

RIP Riverside chicks

Leslie Day holding a fallen chick - May 11, 2008

Cal Vornberger sent a note yesterday:

Hi Marie:

I went over to the 79^th St. nest early Sunday morning and found that all three chicks had not been seen by anyone in at least a day. I ran into Leslie Day there and a woman came up to us and said she saw the female take a dead chick from the nest and deposit it on the grass earlier. The woman picked it up and put it in the trash so the dogs would not get it.

Leslie and I retrieved it and I snapped this heartbreaking shot of her holding the dead chick. I called Lincoln and he came by later and got the carcass from Leslie. He is taking it to Ward Stone for a necropsy.

PS-- Cal Vornberger is a photographer, author of the book The Birds of Central Park

Leslie Day is a naturalist, author of the recently published Field Guide to the Natural World of New York City

Sad news about the Riverside Park redtail family; Blakeman's comments

The Riverside male on Feb. 25, 2008, as nest-building was in progress
Photo by Bruce Yolton

As some of you already know, there is sad news about the Riverside Park redtail nest. The three fluffy white chicks were last seen alive before the severe rainstorm on Friday, May 9, 2008. Observers at the nest the next day saw no evidence of chicks' heads popping up, though the parents were sighted trying to feed sdomething within the nest. Early Sunday morning three bodies were found, and one was sent to Ward Stone, the DEC pathologist, for analysis as to the cause of death..

I wrote John Blakeman yesterday, asking if he had heard the sad news. He replied:


Marie,

Yes, I regretfully learned of the deaths of the three, otherwise thriving eyasses. Quite sad.

But not entirely unexpected. I privately pondered such a possiblity when I first saw the photo of the yellow eyes of one of adults of this pair, indicating that the bird had never bred before. This lethal happenstance is not so infrequent among new, inexperienced pairs. In recalling a few of these incidents, I think they seem to occur most often as this one, when the eyasses are late in the downy stages, before the third week.

I was not aware of the rainy storm event, but that almost surely was the eyass's undoing, hypothermia from getting wet. The inexperienced mother certainly would have attempted to keep her offspring dry and warm, but like ambling human toddlers, they were at an age where they began to have a bit of ambulatory capability. They could start to push themselves around the bottom of the nest and most likely got themselves out into the rain. The inexperienced mother may not have known just how to curtail these lethal wanderings, or to keep the eyasses entirely dry. With her first brood, the attending mother does everything only by instinct; pretty well, at that. But instinct alone isn't always sufficient. The mother will have learned from this and will be more attentive and effective in protecting future eyasses. Nesting failures like this are not uncommon among young, inexperienced Red-tails (as with many other species, too).

Nature (to be teleological -- I cringe at putting it in these easily-understood but not altogether accurate terms) isn't so "concerned" about the survival of every egg laid or eyass hatched. The survival of the species (or population) depends upon the collective success of all of the breeding birds, not any single nest. If a large percent of first-timers are unsuccessful and a bunch of hapless eyasses die, while at the same time experienced adults have high rates of success, the population succeeds. Although each of us lament the loss of the Riverside eyasses, "nature" does not. These deaths may well provide for many years of future breeding successes of this pair.

So yes, this occurs more often than we'd prefer. This is neither rare nor aberrant.

Of course, there is an outside chance that the eyasses were fed a poisoned animal, perhaps a rat. The chances are pretty low for that, however. Poisoned rats generally crawl back into a dark recess and curl up and die there. And most industrial rat poisons (not all, in all cases) are not so lethal to a consuming predator.

Dealing with the loss of the Riverside Park eyasses, along with the disconcerting failure of the 927 nest this year, are things raptor lovers and students must get used to. Only (and properly) among humans should we hope, pray, and expect every offspring to survive and thrive. 'Tis never the case among wild animals, forcing us to intelligently reconcile these disheartening events with the way things really happen in nature.

As much as we all lament these eyass deaths, have any of us taken so much as a pondered breath concerning the multiple deaths of the rats, pigeons, squirrels, and other prey sacrificed to support these hawks? In natural ecosystems, death and suffering are frequent. Only we, as intelligent, pondering, sentient beings can begin to contemplate the "amoral" intricacies of all of this. But whatever personal explanations or understandings finally come to us, there is simply nothing we can do to change any of it.

The ecological intricacies of the lives of all animals are ponderous. But those of creatures as regal the Red-tailed Hawk are particularly deep -- and now in New York City, wonderfully visible. That's why I'm a falconer and a student of wild raptors. Just as with so many now in New York, I've been privileged to personally witness the lives of Red-tailed Hawks, in ways not available to incidental bird watchers and passers by.

I thank all who have so generously contributed photos and stories of the NYC Red-tails, allowing everyone who chooses to see these birds so "up-close and personal." The loss of the Riverside Park eyasses are but a short scene in the entire story. In the manner of "Nature," take no concern. Red-tailed Hawk life in NYC will very well go on. The parents of the lost eyasses will not lament. They haven't the parts of the brain that would allow that. We do, but in this case we shouldn't dwell on the deaths any more than the parents do.

--John Blakeman

Rare Bird in Central Park

Dickcissel on Falconer's Hill - May 10, 2008
Photo by Lloyd Spitalnik - http://www.lloydspitalnikphotos.com

photo by David Speiser [http://www.lilibirds.com]

Yesterday was one of those red-letter days for the Central Park birdwatching community when a rare bird is sighted and the powerful birders' grapevine is swiftly activated. Soon great numbers of people came to the easily located spot -- Falconer's Hill-- and had an opportunity to see a DICKCISSEL, This is a grassland bird of the prairies, rarely seen in this area, and never, or possibly once in Central Park. According to the Cornell website, "Dickcissel populations declined drastically from 1966 to 1978, but then stablized at a lower level. May be declining again in some areas."
Yesterday's Dickcissel was the first of this species I ever saw -- a so-called Life Bird. This was true for quite a number of birders there yesterday. And needless to say the camera-bearing community was well represented at Falconer Hill. Above, two fine examples.

Today's good news: [5/11/08]
The bird is still in Central Park! On e-birds this morning Jack Meyer reported :

The Dickcissel was still being seen at 11:00AM,. and appeared to be settled in for the day. It was on the east side of Falconer's Hill, best seen from the lawn, which is fenced but can be entered through gaps (legitimate ones opened by the Parks Dept).

On Metro Birding Briefs Sandy Spitalnik described the bird's location:

Enter by Strawberry Fields at W72nd St and walk east. Cross the park drive, go slightly south and a little further east up a hill. This hill is just south of the Falconer's Statue on the main E/W transverse, and slightly south of the Lower Lobe (called Wagner Cove on maps)

Good luck if you go.