Saturday, April 21, 2007

Correction and 2 new photos

Lloyd Spitalnik has written in to say that the photo of the Louisiana Waterthrush I posted yesterday was not taken by him but by Cal Vornberger. [Http://www.calvorn.com] Lloyd sent a photo of a waterthrush he did take. You'll find it below, followed by a close-up of a Great Egret taken by Barrie Raik on Saturday, April 14th. Check out the greenish patch going from the base of the bill to the eye, and around. A fantastic color.

By the way, I saw a La. Waterthrush for myself early this morning at Turtle Pond, as well as some Palm warblers and a Yellow-rumped. Also four [count 'em, 4] lovely loons in breeding plumage at the Reservoir.
Lloyd's waterthrush [Http://www.lloydspitalnikphotos.com]

Barrie's Great Egret.

Friday, April 20, 2007

Three new posts today 4/20/07

Nature red in tooth and claw department

The picture above, on Donna Browne's website http://www.palemaleirregulars.com
was identified as a rat delivered by Pale Male to Lola on the nest yesterday afternoon

The photo above, on http://www.palemale.com was taken yesterday afternoon also, but the prey was not identified . Nan Holmes, of Massachussetts, wrote in worrying that it might be Little Red, the much beloved Red Squirrel who's been living in the Locust Grove due west of the Great Lawn for a couple of years. I'm hoping it's the same rat Lola was about to feast upon, photographed a few minutes before delivery.

What do you think?

PS When you click on the 2nd picture to enlarge, it sure doesn't look like a rat leg. Alas.


Liliana's Life List is growing

Louisiana Waterthrush -- last spring
Photo: Lloyd Spitalnik Http://www.lloydspitalnikphotos.com
 Liliana [age 1] saw a Louisiana Waterthrush in the NE corner of the Maintenance Field at 1:30 this afternoon 4/20/07. Her father, David Speiser, claims he saw it too.

Thursday, April 19, 2007

Blakeman responds- and quick local Hawk Report

Pale Male and Lola on the nest - April 19, 2007
photo: http://www.palemale.com


Last year's nest at the Cathedral Church of St. John the Divine
Photo by Bruce Yolton Http://www.urbanhawks.blogs.com


Junior and Charlotte's new nest at 888 7th Avenue
Photo: Bruce Yolton


Marie,

I appreciate Ben Cacace's comments on my posting on the Queens red-tails corner-crash ambush method of taking perched pigeons. Jeffery Kollbrunner just emailed me and said that he has been observing this capture method for twelve years, so it's not incidental or isolated. And he mentioned that he just recently observed a member of a different pair of local red-tails take a pigeon by the same method.

But I'm certain that it's not the only method of pigeon capture. And I have no idea if it's frequently used by the Central Park red-tails. You mentioned seeing a red-tail snatch a pigeon from a flying flock, a feat that seems quite remarkable, given the speed with which pigeons can fly and their ability to maneuver away from pursuing raptors. Peregrines themselves often fail to take pigeons from flying flocks. But I'm certain what you saw happened, that the red-tail somehow took a pigeon from the flock aloft. Was the particular bird taken at the back of the flock, flying with a bit less vigor, or with the slightest handicap? No matter, the capture shows the remarkable new skills of the urban red-tail.

It might be perceived from my recent note that I thought that the around-the-corner-at-speed method was the primary pigeon hunting method of all urban red-tails. Certainly that's not the case, as you and Ben have described other methods. And Jeffery Kollbrunner stated that he's seen low-angle strafing attacks that succeeded.
And of course, red-tails are going to also opportunistically pluck squabs from pigeon nests at will. That would be an instinctive, unrehearsed natural technique any red-tail would resort to upon discovering a plump baby pigeon or two on a building ledge.

Consequently, urban pigeons are being taken profusely by resident red-tailed hawks by a number different methods, ones that I can assure readers seldom or never occur in rural, wild populations (except for nest raids).

My main contention, that red-tails are exceptionally intelligent and adaptive in their hunting techniques stands. I made no mention of their taking of urban mammals such as rats, mice, and squirrels, as these methods surely do not differ from the ones my rural hawks use.

Secondly, the availability of abundant prey controls reproduction (number of eggs and eyasses) and is a central issue in urban red-tail biology. Just how those prey are captured (by multiple methods, many new in urban areas) is a question that needs to be answered more fully. I believe this discussion might prompt urban hawkwatchers to be more attentive and note how the pigeons are being taken. When we understand that fully, we will then understand how the species succeeds so well in its new, urban environment.

And I hope that I didn't convey the thought that red-tails never drink water. They surely do, as Ben has observed. But unlike Cooper's hawks and other accipiters, red-tails do not require daily baths or drinking water. Some red-tails drink and bathe frequently, others seldom or never do. The availability of bathing and drinking water is by no means a requirement for the residency of a pair of red-tails. It is for Cooper's hawks.

Good discussion. Good to hear from people on-site, with first-hand local observations. Until the last 15 years or so, red-tails virtually never lived in cities, never took urban pigeons, and seldom raised young there. As I stated sometime ago, this is all very new red-tailed hawk biology that needs to be documented. Wonderfully, the red-tail is no longer just a country bird -- and in the city it doesn't hunt or feed like it does in the countryside. There aren't any voles in Central Park, the primary prey of rural hawks. But out here, we don't have any vulnerable pigeons, either.

Everyone, please post observed prey captures. I doubt that anyone has the complete picture yet.

--John Blakeman


Local Hawk Report as of 4/20/07

1. Pale Male and Lola:
Still sitting. Eggs should hatch in the next 5 days.

2.Central Park South Hawks [Junior and Charlotte:
Still sitting at their new 7th Avenue nest.

3 Cathedral Hawks:
Still sitting.




Wednesday, April 18, 2007

Redtails and Pigeons continued--meanwhile, still waiting at the Fifth Ave nest

John Sturchio with photographer Cal Vornberger at Owl Bench --2/25/06 Photo: M.Winn



An extremely nice boy named John Sturchio came to see an Owl fly-out in Central Park about a year ago. Now his mother weighs in on the redtail/pigeon debate. Based on her account, I'd say there are many ways these opportunistic birds of prey manage to snag pigeons, not just the single method John Blakeman described a day before yesterday,

PS; Hi there, John Sturchio! Nice to know that you're going on with your birdwatching. Hope to run into you soon.


Here's the message:

Hi, Marie –

John Sturchio’s mom here! John is 9 now – he’s still bird watching, I’m happy to say.
Just read your posts about how red-tails hunt pigeons. On April 2 or 3, John and I were standing in the Locust Grove by the red squirrel’s tree, watching her, when suddenly there was a WHOOSH from behind us, and before I realized what was happening, a red-tailed hawk – not Pale Male – had used its talons to snatch up an unwary pigeon that was standing in the grass and was flying off with the catch to the Great Lawn. He (?) tried eating the dead pigeon on the grass but was so harassed by grackles he eventually took it up to a tree branch, where he spent at least 40 minutes eating it. I know because John would not leave until he had watched the whole thing. He caught a cold, but insisted that it was worth it!

Not trying to get into the fray, just a note about one hawk’s hunting technique. Presumably it was lurking in a tree nearby but I doubt it was really camouflaged, given how few leaves there are on the trees. Also, I would have to say that “speed and agility” were much in evidence – this hawk wasn’t lumbering.

I’m just glad it didn’t catch the squirrel!

All best,

Helen

A response to John Blakeman's comments about redtails' pigeon-catching techniques. It comes from Ben Cacace, frequent website correspondent and blogger in his own right. [Http://novahunter.blogspot.com] In support of Ben's viewpoint I'd like to add that I too have seen Pale Male herding a flock of pigeons high over the Model-boat Pond and plucking one of them out in mid-air.


Marie,

Thanks for posting the conclusion that Blakeman arrived at based on one person's observations of Red-tailed Hawks capturing pigeons.

Without watching urban Red-taileds I'm not sure how one can conclude that if a Red-tailed takes a pigeon this is probably the way it's done. This may perpetuate a partial truth for years to come, not that this is the worst thing in the world. There are so many already, including the one that the hawks don't drink water. I've seen this myself with a juvenile at the edge of the Central Park reservoir.

How many people have seen actual kills of pigeons by Red-taileds? Not many I would presume. I can only remember seeing this once. This happens to be the one on the documentary 'Pale Male' where P.M. follows a flock of pigeons and plunges in to take a bird from the air. Maybe this bird was perched in a tree but P.M. was plunging into the flock prior to the catch. I was there for this amazing display.

How many have seen attempts? Many! Only once can I recall seeing a Red-tailed using the technique described. This was from one of the Trump Parc Red-taileds. One was heading east along Central Park South and flew at a flock of perched pigeons on a rooftop using the buildings as cover. The pigeons didn't see the hawk coming. None were taken.

Recently a friend watched Lola grab a pigeon off a building using the building as a blind. She caught the pigeon but wasn't able to hold on to the bird.

I don't doubt this technique is used. How often and how successful it is would have to be determined by many observations of many kills by an assortment of hawks.

It might be even *more* fascinating. Each Red-tailed may have developed its own techniques. I would stress the plural. Each hawk not relying solely on the one mentioned in your latest post.

Thanks again for making me think about a fascinating subject.

Ben Cacace


Monday, April 16, 2007

Blakeman on how redtails catch so many pigeons in NYC

For good luck:
a photo of Pale Male and Lola's first chicks -- 2002 -- two weeks after hatching

Received today from John Blakeman:

Marie,
I've been communicating with Jeffrey Kollbrunner in Queens, (http://www.jknaturegallery.com/index.html)
regarding his pair of nesting red-tails there. With NYC Audubon, he’s posted a live webcam of the nest where viewers can watch the pair closely. One of the eggs has hatched---perhaps two, by Monday.
Wonderfully, Jeffrey has described for me in detail how urban red-tails take so many pigeons. As noted many times, pigeons—not rats or squirrels or mammalian prey—are the primary food of all the NYC red-tails. This contrasts so markedly from the practices of rural red-tails, where the only pigeons ever taken are ones injured by cars or otherwise first disabled. When I first learned of Pale Male and the other NYC red-tails, I wondered how so many pigeons could be captured so easily by these big, sometimes lumbering hawks more noted for muscular strength, not speed and agility.
I hypothesized that Pale Male and the others must be strafing pigeon flocks while feeding en masse on the ground, taking inattentive young pigeons. Now, from Jeffery’s observations, I don't think that’s the frequent method. How the pigeons are taken is even more remarkable, and reflective of the adaptive intelligence of the red-tail.

Jeffrey tells me that to make their kills, his red-tails will spot pigeons perching on the sides of buildings, either while flying high over head, or from a distant perch. The pigeons will be perched on railings and narrow ledges, just as they would have perched on cliffs in their Middle Eastern lands of origin. On both rock cliffs and modern buildings, the pigeons feel safe from peregrine falcons who can only kill in the air. NYC pigeons almost surely spend more time perched on the sides of buildings than in any other place.

The hawks have figured out how to swoop quickly and unseen from around the corner of a pigeon-laden building and grab the startled birds just as they take off, before they attain any speed. This is a wonderful and intelligent combination of stealth, strategy, and speed, a hunting technique we never see out here in rural areas.

The hawks have cleverly learned to exploit the abundance of urban pigeons, another manifestation of the species’ predatory intelligence. Twenty years ago, no raptor biologist or falconer with red-tail experience would have ever thought so many pigeons could be taken so consistently by these hawks. None of us would have ever presumed the species so able to enter, adapt to, and thrive so successfully in urban environments dominated by turf, tar, and buildings, not meadows and forests.

I thank Jeff for explaining how NYC red-tails so commonly capture pigeons. I now have a more complete understanding of how and why these birds succeed in urban environments. Surely a few pigeons are caught in “brush-crashing” stoops into the foliage of trees where a perched pigeon has been discovered. And some may be taken as I initially presumed, with a high-speed, low-angle strafing plunges into flocks on the ground. But the speedy plucking of perched pigeons off the sides of buildings is the real story. For me, the murk and haze of the pigeon-capture method is lifting.

Brilliant birds, these.

–John A. Blakeman

PS about Riverside Red

In response to the previous post, Nan Holmes wrote:

Dear Marie,
Why is Riverside Red due to leave before the end of April? Is he heading north? If so why such a long stay in Central Park? I always assumed that migration was a rather constant move, stopping only for food or rest. Do these birds make long stays before they make a final push for their summer residence? Given the warm welcome by New Yorkers, why not stay?


Dear Nan:
Some birds spend the winter in Central Park and other parks in NYC and then go elsewhere to breed. Long-eared owls, for instance, have often spent Nov-April in the park, but they never breed there. White-throated sparrows overwinter in CP, and breed way, way north, maybe sub-arctic. Red-headed woodpeckers have never bred around here. Don't know exactly why, but I'd guess it has something to do with the availability of certain foods they need for feeding nestlings. Meanwhile, plenty of acorns around for winter storage and consumption.

There's another problem. He's the only woodpecker of his species in the area. Riverside Red will have to fly elsewhere to find a true love. As for the New Yorkers' warm welcome, it's hard to believe that these ungrateful birds don't give the smallest hoot or whistle or Chork! about whether we welcome them or not. But that, alas, is the sad truth.

PPS Riverside Red hasn't been staying in Central Park, which is in the central part of Manhattan, but in Riverside Park on the island's western-most side. That park, [and the bird's little roosting area] happens to be right outside my apartment building's front door.

Riverside Red

Photo taken on Saturday, 4/14, of the red-headed woodpecker, taken by
Lysiane Ribeiro. [Her nickname for the bird = Riverside Red.]

This bird will be leaving before the month is over, in my opinion. It's a spectacular bird, well worth a trip to Riverside Drive and 92nd Street to have a look .

Photos photos photos

I can post photos again. Here are a few I've been wanting to send out into the world, all taken by DAVID SPEISER. [Liliana's dad].
Common Loon - still on Reservoir

Eastern Phoebe, still many around, flycatching and tail-flicking .


Black-capped chickadee
More than the usual number of them seem to be in the park

Sunday, April 15, 2007

Pale Male & Lola: suspense building

Latest photos of Riverside Park Red-headed Woodpecker
Photos by Lysiane Ribeiro M.D.

Note:
Frustrating difficulties with the provider of this page -- Blogger.com -- and other life circumstances, have led to a week's hiatus. Hope everything goes swimmingly with this new version of Blogger. It will probably look the same when you see it on your computer screens, but requires going through a few new hoops for me. What was it about old dogs and new tricks? I never believed that saying...

Latest update [two hours later]-- thanks to Cal Vornberger I think I've gotten to the heart of my problem-- I just switched from Netscape to Firefox and everything is working perfectly! Photos upload like a dream. Wow.

On to the subject so many of you are waiting to hear about. What's going on with the nest?

According to Jim Lewis, a hawkwatcher since 1995 and the creator of the valuable chart I posted recently, History of the Fifth Avenue Red-tailed Hawks, the window of opportunity for hatching opens tomorrow, April 16. If they eggs are to hatch [please please please] it should happen no later than April 22. After that we'll have to reconcile ourselves to another chickless season.

I'll keep you posted!

As for the spring migration in Central Park, everything seems to be proceeding according to schedule: On Saturday the Palm Warbler was reported at the Tripplet's Bridge, following the arrivals of the Pine Warbler and the Louisiana Waterthrushin recent weeks.

Bird song is getting louder throughout the park -- House Finches and Goldfinches singing as well as robin caroling everywhere, Cardinals, titmice, nuthatches singing their breeding songs. I have been hearing many more chickadee fee-bee songs than I remember from recent years. Flickers loudly calling, woodpeckers drumming and whinnying.

There's a beautiful Common Loon in breeding plumage at the Reservoir--been there for quite a while. I'll try to upload a photo of the bird on this page. [Note: Just tried to upload an image, any image. Failed. Grrrrr.]

Oh yes, the red-headed woodpecker on Riverside Drive. Saw it yesterday.