Saturday, March 29, 2008

The Houston Nest and Branching Opps from the Ground

The Houston St. formel finally makes an appearance. When she is deep in the nest, though the nest is not all that deep, she can't be seen at all from the street in certain positions.

I spent a good bit of time with this view.

Before much to my pleasure, a red tail began to appear towards the rear of the nest. She then looked the area over carefully and put her head into the bowl of the nest.

She begins to turn the eggs.

She shifts slightly and continues.

Tip of tail visible nest right.

Tail disappears and a section of lighter feathers appear. There is a wiggle and once again there is the look of an empty nest.

I haven't seen all the urban nests in New York City as yet, but this one will be another in the running for "worst for fledges."

The nest is just out of frame on the building in the top right hand corner of the photograph. First the six lanes of traffic, the median and the park cars must be flown over in order to get to the London Planes on the other side of the street.

The "green space" across the street isn't really much of a green space. It is the front yard of these housing projects. There is a park of reasonable size a ways up the street but it is surrounded by a tall solid brick wall, with entry for grounded eyasses only through sporadically placed gates.

Yes, there are trees in this space but note the lack of branches until far up the trunk. Even if an eyass manages to fly into the London Planes, once she goes to ground to retrieve dropped food, kill a rock, or any of the other reasons eyasses end up on the ground, she isn't likely to get back into the tall trees until she's much better flighted than the usual newly fledged bird. And when it comes to branching opportunities the pickings are slim in the immediate area.

Note the lack of anything on which to climb in the yard in order to get back into a tall tree. One of the few options in the area are the two smaller trees near the building. But they only lead to the dead end of the small ledge on the building. No tree branches will be near enough for them to use until they have the flight elevation powers that usually take about a week to acquire. It does get them off the ground however.

The building on the other side of the yard, had two smaller trees but the evergreen isn't close enough to anything else use it for transfer. The deciduous tree's branches may not start low enough for a very new fledge to jump into.

Another option, is the playground equipment. The eyasses can get off the ground but they are left exposed and not much in the way of transfer opportunities are available her either.
Fish Park as I mentioned is up the street and I assume that green space would be the safest place to resituate an unhurt eyass found running around grounded on the sidewalk.

I've not compared the measurements between the bars here with those in Morningside which we know a newly fledged eyass can squish herself through with effort, but I think the space is adequate. Which is very good as there is a great deal of this fencing across the street from the nest. A plus is the lack of the taller concrete base found in the fence at Morningside Park.

Here is the side view of the nest. The formel is doing her job and sticking tight. This one is going to be interesting.
I did not observe the tiercel while I was noting the nest and the immediate area.
Donegal Browne
P.S. No, I haven't forgotten about Pale Male and Lola. They will be receiving a visit by the beginning of the week.

Friday, March 28, 2008

John Blakeman's Plum Brook Report

Southwestern Ohio Eagle's Nest courtesy of
Just as I drove up to the eagle nest, before I could stop the car and get my binocs on her, I thought I saw her standing and looking down into the nest in a motherly way. But when I scoped her out, she had settled back in and I couldn't tell if there had been a hatching.

I then drove three or four miles to the other end of the Station to see the over-the-road nest, and try to get a photo of it. The formel was still sitting nicely, but my camera's batteries went dead. I had forgotten to put a pair of newly-charged ones in my back pocket, so I can't submit a photo.

I go in for a prairie burn planning meeting on Monday morning and if the weather is OK (looks like it won't be), I'll try to shoot out to the nest site and click a few photos.

While at the road nest, I, too, had trouble seeing the sitting bird. Until there are some eyasses, the birds stay really low in the nest. And until they start feeding the eyasses, there's really no good way to census the nestlings, so it will be some time yet for the hawk eggs to hatch. The eagle could have eaglets this weekend. The two PBS hawk nest I'm watching appeared to be typical 3rd week in March layings, so eyasses won't be evident until very late April.

On the way back home, out in a big flooded soy bean field a flock of 100 or so tundra swans had taken up residence. They will probably spend the night out there. Very impressive.

John A. Blakeman
And from Brett Odom, still no eggs, no over-nighting, or brooding by Charlotte and Pale Male Jr. at the 888 7th Avenue nest.
AND we wait some more...Donegal Browne

Science Friday--Check out NPR Online

Photograph-Donegal Browne, Lola stands on the 927 nest.
Here's news from Glenn Phillips, executive director of NYC Audubon--

Check out online video – though they didn’t mention her by name, those of you who knew Arlene O’Brien will recognize the reference -

Also, I’ll be on air with Jeff Wells today at 2pm! So tune in to NPR (WNYC, unfortunately, doesn’t carry Science Friday)


John Blakeman--A Plum Brook Station Report Plus Charles Preston Comments on NYC Cavity Nest

Photos: Donegal Browne
The 79th Street Riverside Park Nest, swaying gently directly above a well traveled road.

And here's the intrepid formel sitting tight and swaying right along with it.

If you can believe it, sharp eyed hawk expert John Blakeman has discovered yet another example of Red-tails, yes, building a nest directly above an auto thoroughfare.

And that's not the only reason that things are about to get very exciting at the NASA Plum Brook Station--


The NASA Plum Brook eagle appeared to be off her nest when I went in yesterday, but she was just hunkered down low in the nest. Hatching is scheduled for the end of the week or early next week, so things should get interesting soon.

I confirmed the occupation and incubation at a new Red-tail's nest I saw in February. It's a typical first-time nest, although this one is deep but narrow. The birds chose a very meager nest tree. It's hard to see how the sticks even stay lodged in the minor crotch. It's a tall but very thin cottonwood, which sways inordinately in the wind. But the formel is sitting very tight. She has to have an egg or two under her.

Then, several miles away in Plum Brook, I discovered a brand new nest in a smallish tree, on a branch hanging out directly over a road, perhaps in the manner of the Riverside nest. At first, when driving by, I thought this had to be crow's nest, but it looked a bit too thick. I backed up and put my binocs on the meager pile of sticks and there, too, was another sitting Red-tail. During the season, 20 or 30 cars a day will pass directly under the nest. It's on the road to the Space Power Facility, the world's largest space environment on the surface of the planet. There are 5400 acres within the Plum Brook fence line, and this young pair of Red-tails choose to build a nest 100 feet from the perimeter, above a well-used road, in a tree hardly big enough to support a bushel basket-sized Red-tail nest.

Red-tail behavior is not always very rational.

I should have some fun watching these three nests, however. I'll keep you posted.

--John Blakeman

I can't wait to hear what happens next!

When Charles R. Preston, PhD, author of Red-tailed Hawk in Wild Bird Guides, saw Brett Odom's photo and my musings as to whether there was anyone who knew of any other Red-tail box/cavity nests such as Charlotte and Junior's, he emailed me this comment--


The most similar situation I've seen for Red-tails is on a sandstone cliff space in Colorado, where the nest was placed in a large indention in the cliff face, partially covered by a column of rock. Very interesting!

Best wishes,


Next up: NYC Audubon attempted a raptor census this season, here is The Hawk Report for those who missed their mailing.

The results are listed based on the frequency of breeding by species in the city. Those who breed regularly and in greater numbers are listed first and in greater detail. A large number of birds were found through the census, including eight species confirmed to be breeding within city limits. In addition to the five diurnal species, three species of owl are found in the city year round and are covered separately from the diurnal species. Seven of those species are widespread, the eighth, Cooper’s Hawks, were confirmed as breeding only once. Species not confirmed as breeding within city limits, including migratory species, those found only in winter, and those species found in areas near the city and who may occasionally cross its borders, are not addressed in the same detail.

Cooper’s Hawks, Accipter cooperii
Cooper’s Hawks were the rarest of the species confirmed as breeding in the city with only one confirmed pair and two probable breeding pairs. They were reported in Brooklyn, the Bronx, Queens and Staten Island. The Bronx had no confirmed or probable breeders, Queens had two probable pairs and Staten Island had 1 confirmed pair.

Red-Tailed Hawks, Buteo jamaicensis
The census found 20 Red-tailed Hawk nests in addition to 12 pairs whose nest locations are unknown. Adult Red-tails have been recently sighted at four additional locations however further information was not available. The occurrences of reports of Confirmed or Probable breeding are as follows: three CO in Brooklyn, two CO and one PR in the Bronx, five CO and one PR in Manhattan, four CO and five PR in Queens, and seven CO and four PR in Staten Island. Among the known nesting locations the number of eggs laid and the number of young fledged is unknown. Some nests were monitored closely by various birders, others were not, either due to their remote locations, or the fact that a nest might only be known to a select few individuals. The offspring data that was collected was incomplete due to the same aforementioned factors. Therefore, the numbers obtained are incomplete. Citywide, 28 eyasses were recorded, split up among 12 nests. Two nests were known to have young but actual numbers were unknown. In these cases, the number of young in the nest was recorded as being one. Brooklyn had four young, Bronx had three, Manhattan had eight, Queens had seven and Staten Island had six young.

Two of the pairs whose nests were observed failed to rear young. One of these produced an egg which did not hatch. For the other, no data on eggs is available. All hatched young observed fledged successfully.

This census used a new method to gather information. In the NY Breeding Bird Census, volunteers walk or drive along predetermined routes. At set distances along the route they stop and record all the birds that they hear or see for a specified length of time. The specific quarry being censused, combined with the size of the area involved, made this a difficult approach to take; therefore, it was decided that information should be obtained by interviewing knowledgeable individuals.

Due to the nature of the methods used to gather information, getting precise numbers on any species was difficult. For some species such as Red-tailed Hawks and American Kestrels, the census data are likely lower than the actual numbers due to a lack of adequate coverage of certain areas (as with Red-tailed Hawks) and/or difficulty in finding the birds (as in kestrels). For other species, the numbers here might be higher than the actual ones due to mistaken identification, overlapping reports that are not recognized as such and inability to accurately assess the exact numbers found in an area. In all cases, steps were taken to be cautious and err on the low end. Nonetheless, the final numbers can be considered a fairly representative picture of the city's raptor population.

Cooper's Hawks were the rarest of the confirmed breeding species having only one breeding confirmation and two probable breeding pairs reported. It is notable however that the species is more common than that would suggest- in addition to the three pairs mentioned, Cooper's Hawks have been seen in five additional areas around the city, occurring in every borough except Manhattan. In all instances, the birds have been associated with parks or cemeteries.
Red-tails were the easiest birds on which to find information. They are large and conspicuous. Even better, they have a large number of devoted birders or hawk watchers who keep close track of them. The first pair of Red-tails to live in the city appears to have been Pale Male and Lola; they were first discovered living on 5th Avenue in 1991. Since then, the number of Red-tailed Hawks has grown. The numbers found in this census are likely lower than actual numbers.
While in the wild Red-tailed Hawks nest on trees or rocky ledges, New York City pairs seem to feel equally comfortable nesting on the sides or roofs of buildings. Of the nests whose locations are known, ten nests are built on trees and eleven are nesting on man-made structures. Seven of the latter were built on buildings, two were on bridges, one on a sculpture and one on a crane. A stronger need than nesting on trees or buildings seems to be nesting in or near parks. Of those 21 nests mentioned, only one is not located right next to or inside of a park.

Many of the Red-tailed Hawks in the city appear to maintain small territories compared with their rural counterparts. Moreover, at least one observer noted their increased tolerance, both of other Red-tails and members of other species, intruding on their territories. This could indicate that food availability is fairly high.The reproductive success of the observed nests is high. Two nests were known not to produce young; both of those had reportedly failed to do so last year as well. This may be a result of age or some other biological factor. In order to determine that, more research would need to be done. There does not appear to be a difference between the reproductive rates of those nesting on trees and those nesting on buildings or other structures.

There are still dangers associated with living in the city. One of the pairs that built their nest on a bridge inadvertently built it on a section of the bridge that was slated for demolition. In addition to the nest itself being in danger, nearby trees which could be used by the newly fledged chicks once they left the nest were removed. The wall was left up until the chicks left but what happened to them afterwards is unknown.

There you have it, or at least as much on population as they currently know. Okay, all you Raptor Watchers, let's try for scientific data in numerous categories next season, not just approximate population numbers. Not that population numbers aren't terrific, they are. It's just we could make more of a contribution to the anecdotal literature that might pique scientific interest. Who knows where that could lead? After all we have some of the best views, and the most human habituated raptors in the world!

Donegal Browne

Wednesday, March 26, 2008

Divine Update and One Day of Spring

Photographs: Donegal Browne

James O'Brien, of The Origin of the Species Blog, reports that the Divines have not yet begun to brood eggs but they are very very close to doing so.

One concern, James mentioned, is that as we know Eastern Red-tails are very unlikely to actually make contact with the workman in a defensive move, but they may swoop near by and possibly startle the worker and cause a mishap. Something everyone would like to avoid I'm sure. I hope to have a chance to speak with them soon.

Blue skies and temperatures near the 50's. The birds have vocally gone quite mad and there is an influx of species that haven't been seen for awhile.

In fact I've never sighted a Hairy Woodpecker at the feeders here, but there he was. A little Downy sidled up, thought better of it, and waited her turn. But then the thuggie birds showed up. Here came the Starlings and the Grackles strutting their stuff. Gobbling Suet and intimidating the Sparrows.

The Robins have been singing for some days now and there has been a certain amount of jockeying for territory. Therefore when I saw the second Robin landing near the first I figured the guys were going to go into their "guy stuff" over territory.
Notice the higher Robin looking in the opposite direction. Then on a cue I don't know, but lower Robin does, both males began scolding at a high level. I looked in the direction they were scolding and they were a group of foraging Grackles. The Robins were going into guy stuff, but a different kind of guy stuff than I'd originally thought. It's fine to pick on each other but another species doesn't get to do it. Those Grackles were infringing on their turf. Or that's what I was thinking but never assume.

The boys went at it with a vengeance.
Lower Robin takes a closer position to the feeding Grackles.
One Grackle takes off and flies across the street and begins to scold back in the direction he'd just came from. Complaining at the Robins?
Robin keeps going.
First Grackle is joined by another.
Then another, and another, until it 's a flock. I'm very suspicious that that many Grackles are being intimidated by a couple of Robins. I'm betting there is a Cooper's hiding somewhere which they can see and I can't. The scenario is probably nearer to protective grouping of individuals by species for flock protection from a predator rather than turf.
House Finch who is also new to the neighborhood, has an eye peeled but it isn't keeping him from inhaling sunflower seeds at a great rate. Either he's very hungry from traveling and can't help himself, or he's figuring he can out fly whatever it is that's out there. Ah, Spring, can give that little spark of invulnerability.
But it's not really Spring, I just looked outside and huge inch and a half snowflakes have begun to fall.
Donegal Browne

Trouble at the Cathedral

The scaffolding itself didn't bother Isolde and her new mate one little bit. See Isolde checking the view from the nest with not a care in the world beyond building a strong bond with her new mate? Things were going along swimmingly until workers began repairs directly above the nest. And of course, this phase of the breeding season is the time when hawks are most likely to desert a nest if disturbed.

Photo courtesy of James O'Brien

A frightened Isolde looks up at construction workers on the scaffolding for the few moments she spent on the nest before being flushed off yet again.

For more on the Divine's problems see James O'Brien's blog, The Origin of the Species-
Donegal Browne

Fifth Avenue

Tuesday, March 25, 2008

Pale Male Jr. Update, Blakeman on Brood Patches, and the Grumpy Cooper's Hawk

Photograph: Brett Odom
Junior accompanied by Charlotte's beak, March 22, 2008

Here's Brett Odom's latest update on the 888 nest site--


I'm in the office now on Sunday waiting for Charlotte or Junior to show up and for the sun to get in the right position. Since it doesn't appear that Charlotte is on the nest at 9AM this morning I'm guessing there are still no eggs. That would be a little too ironic, being Easter today.

I have attached a photo that I took yesterday. This is of Junior leaving the nest. Charlotte appeared from behind the glass after he left and flew off after him. You can just barely see her black beak, yellow cere and brown head peeking out on the right side of the window, about 1.5 inches up from the bottom when you open the photo to full size. The rest of her body is obscured by the window.

Brett Odom

Looks like Charlotte and Pale Male Jr. are keeping their reputation for being later layers.
Next up John Blakeman spies a brood patch---


A photo today at shows the naked brood patch on the belly of the Riverside female. This is a remarkable photograph. The brood patch is seldom seen. It is usually covered by the outer body feathers. Here, in a photograph probably taken just as the bird has left the nest, the body coverts (small outer body feathers) have not yet completely closed back up, revealing the bare skin on the belly.

The brood patch lays against the eggs, conveying the mother's body heat directly to the eggs.

Incubation for most of the NYC Red-tails is probably fully underway now.

--John Blakeman

When I drove into the driveway of the house I spied this Cooper's sitting high in the boughs of a tree in the backyard. As you know I've had an immature Cooper's Hawk predating the backyard feeder for most of the winter. When she didn't take off, I thought, "Aha! I've pulled in before and I haven't seen her so she thinks this will be the same old story so she's staying put."

I took a couple of photos from inside the truck, got out, and figured when she saw me looking at her that would be it.

No, actually she turned her head, glared, and went back to her business. I went for another photo and she switched perches to a branch just a few feet away from the original one. I thought, that's odd.

A few minutes later I attempted to move over for a better view.

What did she do? Actually she turned out to be a mature he. Well he started screaming at me. He looked right at me and really gave it to me vocally. "Okay, okay, I'll go in the house." Actually I went in the house to get another camera as it was getting dark.

When I came out again, he called and took off after a songbird. He chased it through some trees, across the street and missed. He then turned around and yelled at me from the tree across the street.

I got the message and retreated sheepishly into the house for good.

Donegal Browne

Sunday, March 23, 2008

Crows Stalking Technique

THE BAIT: I've been quite fascinated by the techniques Crows use to stalk food. It doesn't even have to be moving food. They are, of course, also checking for danger. I'm also interested in food preferences. This offering consists of quite a varied menu--eggs, marshmallows, cornbread, and raw bacon.

8:30AM I hear the Crow before I see her. She isn't just cawing she is doing the almost continuous Crow scream from the other side of the stump from where she is currently standing.

I'm guessing she stopped because if you look carefully you will see a Crow wing on the left side of the door frame. At first I just see only two Crows which is unusual. Ordinarily a foraging Crow party consists of three birds.

Crow One who has been placing her foot on the egg before her suddenly turns and seems to be looking at what looks somewhat bird shaped but was last season a black puffball fungus on the trunk. It has since collapsed. She leaves the egg and goes to the left of the stump.

She then circles behind it and doesn't come out the other side.

Crow Two now comes towards the stump.

Crow Two turns and does what looks like the beginning of a false exit. At that moment Crow Three, who has probably been doing sentinel duty up in a tree, comes zooming in from the right, grabs a marshmallow on the fly and continues left. That's one point for the marshmallows.

Then suddenly with a spurt of energy and extremely loud vocalizations, Crow One who's been behind the stump, jump flaps up, and takes a look. I do not think that she grabs anything.
Crow Three, the sentinel is up in the Spruce keeping watch while knoshing on the marsh mellow. Wonder if his beak will get gooed shut?
Rather reminds me of the ancient Scots who would shriek, and run so furiously at their enemies that nine times out of ten their enemy would be so unmanned as to turn tail and run.

Ever wonder where the model for the ancient Harpies came from? Here you are.
Up she comes screaming, feet ready and yet she too doesn't make a grab. Attempting to look for traps? Or to spring them?
Then a dog walker comes by and all three are gone. At least for now. By the next day, the bacon was gone,, all the cornbread disappeared, the eggs were there, and about half the marshmallows. Of course, I don't know who ate what. One of the outdoor cats could have gone for the bacon before the Crows unearthed it. The sparrows could have done in the cornbread, and on.
That's what I get for not having a goodie stump webcam.
Donegal Browne