Riverside Park redtail update

A photo of the Riverside Park redtail nest-in-progress taken by James O'Brien on Thursday, Feb 21, 2008, and posted on his site: http://yojimbot.blogspot.com/

It's beginning to look like this pair means business! The nest is more substantial now, and the pair has been observed building diligently.
Leslie Day, who first told me about the nest, wrote yesterday:

Hi Marie,. . .I walked by the nest site around 8:30 and there they were, in the park, facing their nest. .. There was a little crowd of people (see below) who had come to see them. Word is spreading! I have been watching them build now for 3 days and I don't think they are done. .
Leslie
But... she mentioned that a dogwalker had reported seeing the pair bringing branches to a different nest site. So...we'll have to wait and see.

Snow Hawks

Friday, Feb 22, 2008. It's NYC's first real snowstorm, and birdwatchers' thoughts turn to how birds fare in adverse weather. I just left a banana for the Scott's Oriole in Union Square Park, missing for more than a week and now back.

And Leslie Day sent a photo of the Riverside Park redtails sitting in a tree in the snow near their new under-construction nest. [See previous post for John Blakeman's comment on this nest. ]

Leslie's photograph in yesterday's posting jogged the memory of long-time Central Park birdwatcher Mary Birchard, who writes about an event more than 15 years ago:

Hi, Marie,

The photo of the Riverside nest on your web site reminds me of the nest that Pale Male and his first mate built near a backstop on the SW corner of the Great Lawn. One could see the sky by looking up through the nest.

Mary

Blakeman about the Riverside Park hawks

Boat Basin in Riverside Park around 79th Street

Marie,

I found the photo of the new Riverside Park nest very interesting. This is a classic new, first nest. Like virtually all Red-tail nests in rural areas, this one's in a real tree.

Notice how you can see right up through twigs on the edge, right under the bird's right wing (on the left). That area needs to get thickened with 10 to 16 inches, or more, of sticks. Right now, the nest is very thin, and still a bit small.

For birds building their first nests, they often stop construction at this stage. It's advanced enough to allow the female sit in pre-egg episodes. It will also hold her and the eggs when the first one is laid.

But typically, the air goes right through the meager bottom of these flimsy first-effort nests. This is probably the first effort of the pair (if they stop at this stage of construction). If the adults are experienced, the nest should become thicker and wider in the coming week or two, with the real prospect of nesting success.

Nest building behaviors are instinctive with Red-tails, but being fully successful also usually involves an experience component. Going through the motions in a first nesting attempt is typical. Every sort of failure can occur with flimsy first-time nests. For some, eggs are never laid. For others, eggs are laid, but they are too cool and fail to hatch. Sometimes the eggs just role out of, or fall through the nest. At the worst (for the eyasses anyway), eyasses may hatch but die from cold or rain. They may even starve, as the young parents aren't yet adept in finding sufficient food for themselves and their offspring.

Might any of this be an outcome for the new Riverside Park nest? No way to know just yet. But if the nest remains as moderate as it is, this one looks like a typical young Red-tail nesting trial walk-through for the pair.

I'm not much concerned about the nest's location over a highway. The birds, adults and eyasses, will pay no attention.

--John Blakeman

---

Riverside Park redtails

Photo by Leslie Day = 2/19/08

I've been watching Red-tailed Hawks out of my fourth-floor window for years. I look out onto Riverside Park, and I've often seen redtails of various ages and sexes hanging out there; one year I even saw a couple of fledglings near the playground at the bottom of the hill at 91st Street. Clearly there must have been a nest nearby that year. But in spite of many hours spent searching the park trees, and the facades of Riverside Drive buildings -- including my own -- I never found a nest.

Day before yesterday I received the above photo and an e-mail from Leslie Day. She's a naturalist and the author of a recently published and excellent book, A Field Guide to the Natural World of New York City, [Johns Hopkins Press].

She wrote:

Hi Marie - wanted you to know about this and then maybe you can spread the word. I first noticed the pair building yesterday morning as I walked my dog and saw a little knot of people staring up. The nest tree is a honey locust and it is next to the on-ramp of the north-bound West Side Highway at 79th Street. This provides a great view for people watching the nest building, but we're worried about the nest hanging over the on-ramp and worried about fledglings being so close to fast-moving cars. Here's a photo from this morning.

A redtail nest in Riverside Park is exciting news. Leslie lives in the Boat Basin quite near to the nest and is following its progress every day. I'll try to keep you posted.

John Blakeman is properly indignant

I posted the previous note about the beauties of the Cornelian Cherry at 10 a.m. today - 2/20/08 . Shortly thereafter came the following properly indignant letter from John Blakeman, with which I essentially agree.

Marie,

As beautiful and seasonally interesting as Cornelian Cherry, Cornus mas, might be in Central Park, it should be understood that the plant is an introduced non-native species.

From that perspective, it might as well be made of plastic or porcelain. Concerning authentic North American ecosystems, the plant has no natural role here.

The beauty of C. mas does not substitute for native species. How many "good looking" foreign plants have been brought to North American for horticultural purposes and have then "escaped" to wild habitats, where they continue to cause all sorts of problems. North East forests are being overtaken by Norway maples. Here in the Midwest (and elsewhere) gorgeous Asian honeysuckles now choke native forests.

The list of horticultural varieties now causing ecological havoc in North American ecosystems is lengthy. Fortunately, Cornelian Cherry does not appear to be a species of particular concern (for now). But those of us who appreciate natural beauty and native ecosystems must be ever-diligent in helping to maintain native species of all sorts. Artificial competition from invasive, non-native species is far and away the greatest threat to natural ecosystems.

Central Park visitors should be welcome to ponder the beauty of Cornelian Cherry, but it's the same as that of pigeons, starlings, and dandelions, all of which are invasive non-natives.

--John Blakeman

Cornelian Cherry

February has more than a week to go and the first flowering plant is getting ready to burst out throughout the park: the Cornelian Cherry, often referred to by its botanical name-- Cornus mas. Many people see a yellow, early flowering shrub and think--forsythia. But the Cornus mas comes out earlier, and is more prevalent in Central Park. The blossom is a beautiful warm golden color while the forsythia [quite a different plant in many other ways too] is a much cooler, almost electric yellow. During its blooming period--the last week of February and the first weeks of March, it is amazing to see how much Cornus mas there is in Central Park: it's everywhere.

[

Blakeman says sprig bodes well

[click on photo to enlarge]

Marie,

One of the photos of www.palemale.com this morning shows one of the 927 birds bringing a small pine sprig to the nest. This is a very good sign. The pine sprig is not merely incidental.

The majority of rural Red-tail nests have these sprigs, even in areas where pines are uncommon. Those of us who study Red-tail nests note the almost universal presence of these evergreen sprigs. We do not know exactly why Red-tails have such an affinity for these, but the majority of active nests have them.

It is thought that the pine fragrance from the twig might repel feather lice and other external parasites, although the sprigs don't seem to placed in the nest with any such intent. If the sprigs were to serve as a louse repellant, they should be put right next to the eggs, under the sitting bird. But more often, they just get placed with all the other structural sticks or out in the open parts of the nest rim.

A second, probably more valid thought is that the green twigs serve as strong signals for nesting and copulating behaviors. The sprigs may be mutually-recognized indicators that nesting, copulation, and eventual eyass-raising will be deliberate, intense, continuing, and purposeful -- green little love notes between the couple, as it were.

If the reasons for pine sprigs at Red-tail nests include any of the latter, and I personally believe this to be the case, the bringing of a pine sprig to the nest this year portends good things.

Again, these sprigs are almost universal in functioning Red-tail nests, and I've always privately wondered why there were no reports of abundant pine sprigs at the 927 nest in previous years. There are certainly a plethora of pines over in the park from which to pluck the sprigs. Some of our Ohio Red-tails have to fly several miles to find a farm-house pine tree as a source. In some areas, there are simply no pines within flying distance and the nests lack any typical greenery.

So, I was very delighted to see this hopeful photograph. It indicates that Pale Male and Lola are going about nest refurbishment with complete thoroughness. They are acting once again like practiced adult Red-tails, fully intent on bringing off a brood of eyasses this year.

The pine sprig, a very positive indication.

--John A. Blakeman

Less than a month

Photo by Cal Vornberger
"First Phoebe of the season" - March 17, 2006


The New York City Bird Report was a marvelous resource that, until recently, offered daily reports of bird activity in most of the city's parks. Many of Central Park's best birders mailed in their daily reports to the NYCBR and helped it keep up-to-the minute. Though it is no longer active [alas!] some of its material is still available on its website. For example, if you click on the link below, you will see a list of the 194 species of birds seen regularly [usually annually] in Central Park, as well as their expected dates of arrival and departure.

Please note the arrival date of the Eastern Phoebe, one of our earliest spring migrants. The NYCBR list says March 20. My own records have it arriving five days earlier, give or take a couple of days. In any event, that's only a month away!

http://www.nycbirdreport.com/sites/1/expyear.html

Other people's sites

Spent the unseasonably warm morning in the park but missed two great birds featured on other nature sites:
From Bruce Yolton's http://urbanhawks.blogs.com
A male Ring-necked Duck on the Reservoir--photographed this morning
[the female was also present]

and

A Hermit Thrush, posted this morning on Http://www.PaleMale.com


Did see a Red-breasted Nuthatch near the Pinetum, and Pale Male circling high above the Evodia Field.