Friday, January 29, 2010

Red-tailed Hawk Update--Kay and Jay in Tulsa, Isolde and Norman Uptown NYC, John Blakeman, Two Peregrines vs RTH, Plus Samantha Raven and Buddy


Photo by Francois Portmann
http://www.fotoportmann.com/birdblog/
Here is Samantha Raven's buddy, the young Cooper's Hawk.
Here we have a great view of one of the ways to tell a Coop from a Sharp-shinned hawk. See the bottom of Buddy's tail? It's rounded. A Sharpie's tail would have a blunt end.


Photo by Francois Portmann
From Francois Portmann in regards to my questions as to possibly why these two, a Raven and a Cooper's Hawk, might be keeping company. (By the way, the first time someone wrote to me about Samantha Raven she was being visited by a trio of Crows. Usually a threesome of Crows means they are a foraging party.)

Donna,
Well not sure about that duo.
People feed Samantha and that could be a reason for the Cooper to be there, maybe he gets scraps!!
Red-tail hawks catch pigeons there regularly, that’s more left overs too.
The Cooper is active and alert, keeps hunting around the place but I’ve not seen him catch anything yet
Looks well fed though! (pics last nite and today in the snowstorm)
["Today" would have been Thursday, 01/28/10]
See you,
Francois

Well fed? I'll say. Just look at that crop bulge.

Francois,
I take it you have never been around when both the birds are there and Samantha's meat is brought to her? Would you care to experiment and find out what happens?

As food is already being brought in, it wouldn't be teaching either of them anything they didn't already know. I think I'd be very tempted to put it to a one time test to see what happened.
Photo by Cheryl Cavert
1/14/10 Jay does some work on the nest.
From Tulsa Hawkwatcher and photographer Cheryl Cavert, some photo history of Kay and Jay's alternative nest site--
Hi Donegal,
A few photos from January 14th and 18th, 2010 that show Jay at the alternative nesting site and a few views of the nesting material. Jay is perched a level below the nest - however I still did not notice the nesting material gathering for a few more days!
--Cheryl


Photo by Cheryl Cavert
1/18/10

Photo by Cheryl Cavert
1/18/10

Photo by Cheryl Cavert
1/18/10

Photo by Cheryl Cavert
1/26/10 Visit by both Kay and Jay
THERE SHOULD BE A PHOTO HERE FROM 1/05/09 SHOWING NO TWIGS ON THE PLATFORM BUT BLOGGER ATE IT.
Also from Cheryl Cavert some commentary on the photographs--
The first photo from January 5, 2009 does not appear to show any nesting material on any of the platform levels.


Photo by Cheryl Cavert
On May 1, 2009 sticks are visible. This was a few weeks after their nesting failure on the KJRH tower; however, I do not have any photos taken in between those dates so I cannot confirm when they began depositing a few sticks there


Photo by Cheryl Cavert
The third photo is from October 31, 2009 of Kay at the alternative tower - we still did not notice the sticks gathering on the platform!
(More photos from Cheryl of Kay and Jay coming soon.)
Upon request, here is what John Blakeman has to say about the Tulsa nest situation. Plus more on hawks and pigmentation.

Donna,

I can’t tell much about the status of the Tulsa red-tail nests. It’s not that the photos are inadequate; rather it’s because it’s just too early in the reproductive season for anything to be firmly set.

Right now, the breeding pairs are just going through motions, with nothing firmly set yet. Nest construction right now is generally pretty cursory and incomplete. As you mentioned I believe, red-tails commonly will start building alternative nests in January and February, but then when things get serious in March (at least in the northern tier of states, earlier in the South), the pair often goes right back to an older, well-established nest and finishes the nesting season there.

Or, they just up and abandon the old nest and go to a new one, even if the old one is in good shape. Now Pale Male has not done this, but nest site fidelity with the other Manhattan red-tails has not been as consistent. I see this with my rural red-tails, who rather frequently build and use a new nest less than a half-mile from the first one.

Sometimes this is prompted by a great horned owl, which drops in and expropriates an existing red-tail nest very early in the season, often in December. But more often, the hawks just elect to build a new nest nearby and use it. Why this annual nest site vagrancy? I don’t know, other than, perhaps, for the strong pair-bonding that results from nest building. The birds just love to carry sticks and lining around and build a nest. It must be a very gratifying and psychologically rewarding thing for them to do. They expend a lot of energy carrying all those sticks around and tucking them in to make the foundation of a new nest. Then, they have to bring in many flights of leaves, lose bark, and dead grass clumps to form the insulating lining of the nest.

The pair spends a lot of time and energy in doing all of this, often with no useful physical result, when they go back and use the older nest. They must really like all of this nest construction.

Too early to tell about the posted nests, however.

In an earlier posting, my explanation of the source the skin color in red-tails was incomplete. I mentioned that the intense yellow color of the skin on the legs of haggards was derived from the carotenoids of vegetation found in the gastrointestinal tracts of the prey they capture and eat.

But I forgot to mention that they do not gain any coloration from the fur or feathers of their prey. A hawk might capture a very colorful bird, a blue jay for example. But none of the colors in the feathers of these birds could ever end up giving color to the hawk’s skin or feathers.

That’s because in birds, feather colors come from only two sources. In most, the colors are forms of melanin, which when eaten by a hawk gets completely digested, so it can’t end up yielding any color in the hawk.

The second source of feather color is without any pigmentation at all. It’s by refraction, where microscopic structures of the feather bend or refract the reflected light, allowing only certain frequencies to be reflected. This is the case with blue jay feathers, which have absolutely no blue pigments at all. It’s all, as it were, light and mirrors, or at least light and light refraction into blue hues.

So, no, hawks don’t derive any skin or feather color from the skin or feathers of the prey they eat.

–John Blakeman

That's a great point about the hawks and nest building. It being that time of year, the hawks have a great urge to build. Satisfying that urge would feel good. Just in the way, when we humans have a great urge to do something and we do it, often there is a feeling of great satisfaction.
Or in the case of the descending urges from hormones when leaving a nest, particularly a failed one, pairs may start building a second nest or in Pale Male and Lola's case twigging activity before leaving the nest ( a month later than there should have been the cues of a hatch to trigger the next stage of hormonal cascade) they go through an agitated period of bringing in new material and nest rearrangement.
AN UPDATE ON ISOLDE AND NORMAN OF MORNINGSIDE PARK FROM NARA, WHO'S FIRE ESCAPE THEY INTERMITTENTLY ROOST UPON--
It's official...
...we are clearly the preferred roosting spot for very cold nights!
After a long hiatus, our feathered friend is back, nestled on the second step of the fire escape. I assume the mate is a few apartments down, though I didn't see him from the sidewalk and I'm not sticking my head outside the window to check.

It's supposed to stay cold through the weekend, so here's hoping they stick around for a few days.
Nara
AND A PEREGRINE VS RED-TAIL UPDATE FROM JAMES O'BRIEN,
I had both Peregrines attacking an adult Red-tailed Hawk today at noon over the north end of Morningside Park. The hawk eventually landed at the second to the top air conditioner of a tall brick building along Morningside Ave. They like those spots along Morningside because they are out of the harsh wind. Plus they provide a blind from those nasty peregrines!
James

James is being facetious of course; he is speaking from the Red-tail's point of view. He doesn't really think that Peregrines are nasty as he's been watching the pair on Riverside Church for years. His "watching" has included such activities as running into traffic to help one of their fledglings who had plopped down into the street.
Donegal Browne

Thursday, January 28, 2010

NYBG Great Horned Owls, Samantha Raven and the Cooper's Hawk Plus More on The Houston Red-tailed Hawk


New York Botanical Garden Contributor Pat Gonzalez has been diligently scouring the NYBG in hope that the Great Horned Owl pair that nested in the garden last year just might return this year, and guess what?


Donegal:

Check out the attached photos. I took them earlier today (Wednesday, Jan. 27th) at the NYBG.

Is it too early for me to break out the cigars?


Male Great Horned Owl

You should have seen the look on the male’s face when he saw me. It was like, you AGAIN? He turned his head away and completely ignored me just like he did last year. : )

Here's a short video I shot of him. Sorry for the shake, I had no tripod.

http://www.youtube.com/user/NATURECAMHD#p/u/0/gxrGoqudM-8

Pat
P.S. I'm keeping mum about their exact location, the pruning has made the trail that leads near where the tree is much more visible than last year. It is no longer hidden. Can you recommend a good cigar store? : )


Alright Pat, thank you for catching them in the act! I can't wait until you start catching those little heads coming up next to Mom's.

Photo by Francois Portmann
Remember Samantha Raven who lives in the cemetery?
(More gorgeous photos of these two on Francois Portmann's blog, link below.)

For those who don't remember her, here is a small recap-- Samantha, who is a raven from upstate NY, had an injured wing and though two different vets attempted to fix the wing surgically, it was just too damaged for her to regain flight so she came to live at the cemetery where she had been doing remarkably well.

That is until it was reported that she was nabbing pigeons and eating them. The pigeon eating disturbed some people and this almost got Samantha evicted. But she appears to have gotten a reprieve as she is still in residence.

This Samantha update from nature and wildlife photographer Francois Portmann--


Hey Donna,

In the same hood as the Houston Hawk there is an unusual raptor/corvid friendship going on:
http://www.fotoportmann.com/birdblog/
Greets
francois

I would love to know what those two are up to? Corvids are known to be social but usually hawks are seen as quite solitary when it comes to hunting. Though I have seen two Cooper's Hawks attempting to double team prey so they can work cooperatively when food is at stake.

Just what might this symbiotic relationship be about? Do they have a relationship because of food in some manner or is it just the company?

One season in Central Park there was an immature Cooper's and an immature Red-tail who almost looked like they were playing at times. One would do a stealth flight behind the other, knocking that bird off its perch. Then the bird that had been unperched would do the same to the other. It was suggested that it was all about being king of that particular perch, but the behavior was seen happening on different perches at times. I suppose it could just have been personal antipathy but as they were both young might it not have been play?

When you check out Francois' photographs, look at the first photo of the two together. Samantha's expression would preclude that kind of horseplay. Though beyond what we expect, perhaps the urge to have someone to hang with for a first year hawk, having just left his parents and siblings for the first time and a Raven who would ordinarily have an extended family isn't as extraordinary as we might think.

And of course there is that possible hunting partner/food angle too.


MORE ABOUT THE HOUSTON HAWK FROM FRANCOIS, THE DAILY NEWS, PLUS BOBBY HORVATH'S TAKE ON "IS SHE OR ISN'T SHE THE FORMEL FROM LAST YEAR'S PS188 NEST".

For those who asked where Francois' current photographs of the Houston Hawk were taken. Here is his answer.


The location of the pix is 4 avenue blocks to the west from the ps188 nest.
Btw, the school bldg is still in renovation and wrapped in netting, so no way to nest there!

(A likely blessing, as the previous nest site on the school was a fledglings nightmare. D.B.)


Interestingly, there was a daily news article yesterday regarding the Houston Hawks
matter:
http://www.nydailynews.com/ny_local/2010/01/26/20100126_swoop_there_it_is_redtailed_hawks_are_enthralling_nabe_from_lower_east_side_perc.html
(As this link is long, you may have to copy and paste to the address bar to see the original article.)

All eyes to the sky in lower East Side: Two red-tailed hawks captivate locals
BY Daniel Edward Rosen
DAILY NEWS WRITER

Tuesday, January 26th 2010, 4:00 AM

Red-tailed hawks that like to swoop around the lower East Side are captivating the local humans.

Lorraine Sepulveda, 53, a mother of five who has been "stalking" the majestic birds for two years, said she saw one perched up on the roof of a building at E. Houston St. and Avenue D on Sunday, "just hanging out like a superhero."

"I said, 'Omigod! I've been looking for you,'" recalled Sepulveda, who said she bought a pair of binoculars just to keep track of her feathered friends from her apartment at the Baruch Houses.

Johnny Reyes, 18, a neighborhood resident who has dubbed the hawks "the sky beasts," said, "They come down and they eat squirrels, rats, birds.

"People who walk their little dogs are always looking out for the hawks."

Hawks first appeared in the neighborhood in spring 2008, when two of them built a nest for their three fledglings.

Their choice location was a fifth-floor air-conditioning unit at Public Schools 9-4/188 on E. Houston St., according to school custodian and bird enthusiast Bill Tatton.

After losing the male hawk and two chicks to bacteria contracted from what Tatton calls "bad pigeon," the two surviving hawks left their nest but remained in the neighborhood, flying around to hunt for food.

Tatton has documented the hawks' presence with photos over the past two years.

"These birds are so powerful and so beautiful, how can you not be inspired?" said Tatton, 53, of Pelham Bay, the Bronx.

So far no one has attempted to name the powerful birds.

"I wouldn't go as so far as to give a bird of prey a nickname," said Tatton.

As of 2007, 32 nesting pairs of red-tailed hawks were identified across the city, with many more of the species, possibly hundreds, passing through the five boroughs each year, according to Sarah Aucoin, director of the Urban Park Rangers.

The most famous city pair were Pale Male and Lola, who roosted on the upper East Side.

"The hawks who are able to successfully nest and reproduce and find good hunting tend to stay," said city Parks Commissioner Adrian Benepe.

"In recent memory, there have never been more hawks than there are now in the most unusual of places," Benepe added.



From Wildlife rehabilitator Bobby Horvath in response to Francois' Houston Hawk news--

Hi Francois,


From the reports and your pictures I would bet it's the same bird. It's a big bird so female and its banded on the right leg ,which we use for all girls . I compared your old and new pics and looks to me to be the same bird. It would be a huge coincidence for it to show up at the same location and not be last years bird.


Yes there are many more redtails each year showing up in the city but to be banded on the right leg and have the same appearance , lightish head to light breast makes me say it is the same bird. If it starts showing up
on the rooftops of the school and or adjacent apartment houses then no
doubt.



Keep us informed of what you see.


Thanks,
Bobby

And video of a Red-tail Hawk and Gray Squirrel Interlude in Washington Square Park by KZdiamond
http://www.youtube.com/watch?v=RhnCQnCJFFM



Donegal Browne

Tulsa Nest Question, Blakeman on Red-tail Skin Pigment, and the Innocent Bystander Burnt Bird


6/30/2009

Sally of Kentucky has sent some screen captures from the KJRH TV web cam for us to scrutinize.
Here is her email--

Dear Donna,

As I know you have heard, Kay and Jay have been seen working actively on what appears to be a new or alternative nest site on another tower in the area of the KJRH tower nest. We have not seen much if any change in the nest they used last year in the brief views of it which we have been allowed. Because the weather cam has not been trained on the nest for long periods of time with any regularity, we cannot observe for long periods if they are visiting that nest, and if so how often.


11/03/2009
The few occasions we have had a longer viewing period no hawks were seen. Our only guide right now is the occasional on the ground observation of them and the brief glimpses of the nest which we try to analyze for subtle signs they have been working. Yesterday, however, Catgirl observed both hawks on the KJRH tower and Jay actually up on the nest working, though, he was not observed carrying anything to the nest. Kay was on an adjacent part of the tower apparently ignoring his efforts. We think the nest looks move-in ready, so is it possible that they will not add much to it this year, that they are happy with its present state, but feeling the need to do something are spending time on the alternate site?


12/16/2009
That site at this point is no where near thick enough to have a nest this year. We are looking for hope that they will return to the KJRH nest this season! What do you think? Would Blakeman have time to comment? I have attached a view of the nest from this summer and one from a recent capture for you to compare. I apologize the quality of my screen captures is not very crisp. Its all I have! Thank you.

1/19/2010
Sally,

I'll ask John Blakeman to take a look. In the meantime, if the secondary nest is disorganized and doesn't have enough material, and remains that way, it is likely just that, the secondary nest that is seasonally built so the female has a choice.

Even Pale Male and Lola do it and they've ended up nesting on 927 for years anyway.. They've been observed at various times moving twigs onto the Beresford over on the Westside, but it never gets to nest-ness. If the secondary Tulsa nest begins to really look like a nest then it might be a true option instead a matter of form.

As you probably remember some people believe that when the evergreen twigs appear on a nest that the choice has been made. I don't know for sure that's true for all pairs but some folks swear by it.

When have Kay and Jay started to lay in past years? I know they're earlier than NYC. PM and L tend to take to the nest with a clutch usually within the first week of March, with first observed copulation the end of January, or beginning of February, approximately a month of copulation before sitting. So as Kay and Jay are earlier, they might already be copulating. Therefore this would be the big time for them to be doing as you say, nest-eration.


In the past has Jay been the one doing most of the building or does Kay do a lot too? It seems to differ according to pair. Lola is bigger on rearranging than actually bringing twigs though Pale is pretty big on arranging as well, he’s the one I most often see bringing twigs. Lola is the one who gets the bark for the nest bowl. I've seen both getting the dry grass.

Don't worry about the lack of photo sharpness, it’s super to have the documentation for comparison.

Speaking of Ohio Hawk Mavin John Blakeman, here is more about the odd and interesting variation of skin color in young Red-tailed Hawks--
Donna,

Regarding skin pigmentation in hawks. You are absolutely correct in noting that the wild prey of hawks includes the food contents of the prey’s stomach and intestines. These rodents and birds eat seeds, vegetation, and insects that all have colorful (and healthful) carotenoids.

These plant pigments are absorbed by the consuming hawks, yielding the intense, saturated skin colors of feet and ceres.

As mentioned, however, there are a few first-year wild red-tails who don’t have yellow feet or ceres. After having trapped many dozens of wild red-tails over several decades, I’ve noted that leg skin colors vary from very intense yellow, to a hint of yellow, on to a rather meager blue-gray in a few birds. Is this variability purely genetic, or does it reflect a preferred food source that doesn’t eat many colored vegetables? I don’t know, but I think it’s probably genetic. A few birds apparently can’t so easily absorb or utilize these plant pigments.

Are these birds then less healthy, less likely to make it through their first year? I don’t know—one of many dozens of red-tail questions that need answers.

–John Blakeman

Well, John, yet another fascinating field study and dissertation waiting to happen. Do you happen to know if there is any particular area in which there are more of these non-yellow footed youngsters than others? Of course if there were we still wouldn't know if it was genetic or food related or both but it would be a lot easier to figure it out if there were such an area or grouping of hawks.

Contributor Ken Zommer of Chicago sent in this tale of one tough Red-tailed Hawk and a plane crash--

From The Chicago Sun Times January 26, 2010

http://www.suntimes.com/news/sneed/2010984,CST-NWS-SNEED26.article

BY MICHAEL SNEED Sun-Times Columnist

The burnt bird . . .

There's always a story behind a story.

This time a bird is involved.

An unlikely bystander was injured by the fireball caused by a Saturday night plane crash in Sugar Grove, which killed two people on board.

The bystander: a red-tailed hawk.

The raptor rescue began with a report of "a bird on the ground" near the wreckage site by Kane County Animal Control.

Apparently perched in a nearby tree before the crash, the roasted raptor was found standing in the snow when firefighters arrived.

"She's alive, but it was close," said Flint Creek Wildlife Rehabilitation founder Dawn Keller, who triaged the hawk for 75 minutes at her group's Barrington rehab site.

"There is not a single feather that's not burned off of that bird's body," she said.

"I've never seen anything like it. Quite honestly, I think it's a miracle. I can't believe she's alive," said Keller.

"We now call her 'Phoenix' after the mythical bird which was consumed by fire but rose from the ashes.

"I have treated her every four hours since then," she told Sneed.

"All that's left is the really fine down feathers close to her skin that provide insulation and waterproofing -- and these four- to five-inch long charred black shafts that used to have feathers on them."

"Every inch of exposed skin was charred black -- she just smelled like a fire -- the top layer of skin on the feet hanging off," said Keller, who had to gently remove the dead skin and apply burn cream before bandaging the bird.

"But she's doing well, I mean she's standing. Her feet are all bandaged, but she's standing. She's not eating yet. She's on fluid therapy, pain meds and antibiotics," said Keller.

• The big question: Could the bird have caused the crash?

"There's no chance this bird could have caused this plane crash," said Keller.

"The crash happened after dark, which means she was already sleeping for the night. If she got sucked into the propeller or engine she'd be dead. She was just an innocent bystander who was in the wrong place at the wrong time."

• The hawk's future? "Her release to the wild depends on her vision. It really comes down to her eyes at this point.

"The veterinary ophthalmologist said her outer eyelids are damaged, but they did protect the cornea. Now we need to treat the eyelids to save them."

• Prognosis: "We expect the bird to survive. Only time will tell if we can release her -- it depends on her eyelids healing correctly," said Keller. "If the bird can't be released, we'd try to make sure she is used for educational purposes -- like showing her at area schools."



Donegal Browne

Monday, January 25, 2010

FLASH:Has the Houston Formel Returned? Blakeman, Horvath, and Sally of Kentucky on the New NYBG Mystery Hawk Plus Betty the Crow Uses Three Tools


Photograph by Francois Portman
http://www.fotoportmann.com/birdblog/

From downtown hawkwatcher, bloggist, and professional photographer Francois Portman--

Hi All,
The Red-tailed Hawk (left & center, see attached) has been seen regularly around Houston Street/1st Ave. area, there are thoughts that she could be the Houston female
of ps188 nest (at right)
Unfortunately the band # is unreadable!

Hope you're well
Francois

We won't know for sure until someone gets a good look at her band, but the hawk on the right certainly looks like the same hawk as the one on the left and center to me.


One of Pat Gonzalez's photos of the current New York Botanical Garden Mystery Hawk

Boy did I blow it. My advice? Don't try to identify hawks at 4 in the morning. Therefore I plucked some photos from here and there to illustrate (to myself in particular) what Red-tails look like in different life phases, illumination, sexes, times of year...

Remember I asked for suggestions from the house on the matter? Thankfully a number of folks took me up on it. But first a few hawks under different conditions.
hotograph by Donegal Browne
A tired Isolde feeds on the nest in April. See the bags under her eyes?

Photograph by Donegal Browne
The same time frame as the photo above, Tristan the tiercel, though hunting ceaselessly doesn't really look the least bit tired.

Photograph by Donegal Browne
In no time Tristan has a rather large rat for the himself, Isolde and the family. Here he goes into a crouch scoping another, is perfectly still, and then, I assume when the prey looks the other way, zips to the next branch over and is perfectly still again. Tristan was a master of stealth.

Photograph by Donegal Browne
Tristan now on the next branch over. Here we have a excellent view of a reasonably good field mark for RTs from the rear in both a juvenile and a mature bird. Though rare, some RTHs do not have it. Tristan had it in spades. See the dark and light patches forming "backpack straps" on his back?


Photo: Donegal Browne
Notice what happened to Tristan's feather color when the light changes. Compare this photo with the two above that are anterior shots of him.



You'll also note that Tristan was just as big on giving beautiful photo ops as Pale Male is.



Tristan's presence is still sorely missed.

Photograph by Donegal Browne
Pale Male sits on Linda 4 in the rain, near the end of the extra month in which he and Lola tended an unsuccessful nest. During the last few days he'd been spending many hours on the nest as Lola was taking extremely long breaks. He'd just brought her food; see the blood on his beak.

Photograph by Donegal Browne
Like the NYBG hawk this is a first year immature January Hawk. Quite different. A formel?
Photograph by Pat Gonzalez
We're back to our current New York Botanical Garden Mystery Hawk who is now not quite so mysterious--First off a missive from wonderful rehabber Bobby Horvath, who has had his hands on many many hawks of all kinds--

Hi Donna,

The bird looks like a juvenile redtail to me but I could be wrong. It's definitely not an accipiter. Too big headed and toed to be sharpie or coop and tail not long enough but sized right for a juvenile goshawk. If its not a redtail my second guess would be a juvenile red shouldered hawk.


One more thing, it appears to be banded on its left leg. Very rare for goshawks to be trapped for banding but red shouldereds do come into rehab pretty commonly so I'd bet its one or the other.

Bobby

Many thanks Bobby! Extremely helpful.
Photo courtesy of www.howardsview.com/

How about this hawk? It's a juvenile. It's shaped like a buteo. He has chunky yellow toes.

Look at the feathers near his feet. They seem to have a similarity in their greyness to the NYBG hawk above though certainly a darker hawk than that one overall. And it does have some brown and white splotches on it's back. The beginnings of "backpack straps"?


No, actually. This is a juvenile Red-shouldered Hawk. An example of one of the species Bobby spoke about above. His second choice for an identification of the NYBG hawk.
Blog contributor Sally of Kentucky who volunteers at a wildlife rehabilitation center and has dealt with numerous species also sent her thoughts--

Dear Donna,


This juvenile bird's feet seem pretty sizeable to me, heavier than any accipiter I have seen at least in my limited experience, and the tail isn’t as long as say a goshawk or a harrier.
I looked at pictures of these two species and I do not think it is either, nor do I think it is a RSH (Red-shouldered Hawk- D.B.) with those heavy feet. What other hawk could it be in New York if not a Redtail?
Agreed the white on the face seems unusual and I also think it looks different than most juveniles I have seen; perhaps it is just the facial coloring throwing us off? I wonder what Blakeman says.

Sally

Speaking of Ohio Red-tail expert and falconer John Blakeman, here is what he had to say, plus my questions on the matter and his responses--

Donna,

The mystery hawk is an immature red-tail, almost surely a tiercel.

The general body shape is pure red-tail, along with the head shape, position of the eyes in the head, etc.
The tail feathers aren't long enough or appropriately positioned for an accipiter.

A number of immature red-tails retain a general blue-gray pigmentation of the legs and cere (exposed skin on the beak).

--John Blakeman

John,
I was thinking about the NYBG bird when I woke up this morning and I kept going back to it in my mind-- its body is shaped like Pale Male, Tristan, and Junior, the quick compact model of Red-tailed tiercel, unlike Atlas out near the Triborough Bridge for instance, but the feet seemed so weirdly colored and maybe a little fine toed too.

Thanks so much for the information on the immature pigmentation issue. I had no idea. As far as I remember none of the eyasses in the city I've watched have had it.

But as we know, one of the true wonders of this whole thing is there is always something new about those pesky Red-tails.
D.

Donna,

The coloring of red-tail skin, as in other birds, is primarily a result of pigments in foods. Hawks eating animals that feed on seeds and vegetation have these phytopigments. But for reasons I haven't yet figured out, a few immatures have rather bland blue-gray pigmentation.

Actually, this is a lack of pigmentation, for unknown reasons. The major factor is the concentrations of these carotenes in food. But it appears that a few immatures don't concentrate these in skin during the first year very well.

And here's a coloration matter I've always wondered about, as have most falconers and rehabbers. Plainly, the skin coloration of wild adults is almost always far more deep and intense than birds kept in captivity, even those fed lab rats and mice. The feet of my new red-tail, Zephyr, are yellow, but not nearly as intensely colored as wild-feeding hawks. Wild birds, somehow, eat things that give them deep skin color (except for a few immatures, such as the one in the photo).

--John Blakeman

John,

Regarding the matter of captive raptors having paler pigmentation then their wild relatives, even those fed lab rats and mice. Here's a thought for what it's worth.

Wild mice and rats have a varied and seasonal diet. Even urban pigeons have a special taste for begonia leaves and other greenery when in season whereas lab mice and rats are likely fed a steady diet of prepared rat or mice chow. While the mouse chow may be perfectly nutritious it just doesn't provide those fresh foods that contain the colored pigments found naturally. And as I think we've discussed before in another context, when a hawk swallows a mouse, vole, or other small rodent, they swallow it whole. So hawks get their veggies from the undigested food inside their prey. And those whole foods, instead of processed ones, would seem more likely to me to contain pigmentation which then colors the hawks. Possible?


Donna
P.S. Urban raptors also eat a certain number of pigeon feathers, which do come in a variety of colors. I've seen them get down any number of flight feathers which is always rather amazing to watch. I wonder if those feathers also contribute to a raptor's coloration?

Last but not least, it wouldn't be a blog post lately without something from the amazing tool wielding Betty the New Caledonian Crow--

Contributor Robin of Illinois has found more video. This time Betty uses three tools in sequence to get the goods. no question this bird is a grub procuring whiz!
http://www.youtube.com/watch?v=41Z6Mvjd9w0


Donegal Browne

Sunday, January 24, 2010

Wednesday at the New York Botanic Garden and More on Avian Tools


Photograph by Pat Gonzalez
Hooded Merganser

Our birder of the New York Botanic Garden Pat Gonzalez has quite the day:

Donegal:

The attached photos were taken on Wednesday, Jan. 20th at the NYBG.

At 10:25 AM, I noticed about six hooded mergansers. I could make out at least one female. They were swimming in the Bronx River just off the Magnolia Way overpass. I was walking on the Spicebush trail in the native forest and was able to see them clearly. Even though I was waaaay up from were they were, looking down at them, I knew that if I made any sudden moves, they would bolt, so I took the shots where I stood.


Photo by Pat Gonzalez
At 10:41 AM in a different section of the forest, a hawk landed on the top of a dead tree. It is the camera angle, the sunlight or me? This hawk looks a bit different from a red-tail. Even with my zoom lens all the way out I still had to crop these photos. Donegal, what do you think?

Photo by Pat Gonzalez
Pat,

Could you tell anything about the size of the hawk from where you were standing? I'm wondering if it is an immature Accipiter. Perhaps a Sharp-shinned?

There are a couple of odd things here which tend toward the bird being something besides a Red-tail. And as we know unless one can see both the tail of a hawk and her belly, it's a tough call.
It could be the light but a Red-tailed Hawks feet are quite a vivid yellow and thicker toed than this bird's feet appear.

This bird looks quite light eyed even if it were only a first year juvenile RT.

There is something odd about the coloration, particularly on the hawk's side. Somehow it doesn't seem to be a warm enough brown for an RT. A clear breast and a belly band instead of a possibly over all streaked anterior would be telling but the hawk just wasn't cooperative about giving us a 360 degree view.

The tail appears longer and slimmer than a buteo.

And at least from this angle, the final bar of the tail looks thicker than the bars higher on the tail.

That said I'm open to suggestions from the house.

Turtle
When I got to the bank of the Bronx River, I was surprised to see a turtle moving under the water. He found a spot, and then stopped, just laying there. In the attached photo, he's just to the right of the branch.


Male Wood Duck, Aix sponsa


At 11:50 AM I was walking along a different section of the Bronx River, just off the Stone Mill Road overpass and saw the usual gang of suspects: a LOT of mallards, the mystery farm duck and later, a couple of Canadian geese.

I was standing right on the river bank, in the mushy soil, when I noticed a beautiful male wood duck. He was spinning, bobbing his head back and forth, opening and closing his beak. I think he was trying to impress a female who was nearby.

As Wood ducks always run (with the exception of the very friendly lone female from last week) when you so much as blink, I moved VERY slowly, ducking behind a tree to get closer to the edge of the bank.
Here's video that I took which I posted on youtube.

http://www.youtube.com/user/NATURECAMHD#p/u/0/QJfc0bS-YoU

But it was hard getting a clear photo, because this little duck just couldn't keep still. Attached is the closest shot I've ever taken of a male wood duck.

All in all, a very good day.

Pat Gonzalez


Louie yawns (relieving ear pressure?) while using his feather tool on his ear.

Re Louie cleaning his ears....versus scratching from Linda, Louie's owner, via Robin of Illinois.

Linda writes:
You know....I don't think Louie is cleaning his ears, he's just scratching
the inside. Don’t know if parrots get wax in their ears :)

(As to the possibility of Avian ear wax, you never know, right? So I did a rudimentary search which brought no evidence of the substance nor have I seen any evidence of it with Quicksilver the African Grey. D.B.)


Robin writes:

Linda also said that she discards the tool feathers when Louie is done, so she doesn't really know if he would stash them for future use, since she hasn't given him a chance as yet.


Photograph by Donegal Browne

Also from Robin of Illinois, Crows using traffic to crack their walnuts for them--the automobile as TOOL?

COMING SOON, TEMPERATURE AND THE FIRE ESCAPE ROOST OF THE DIVINES, ISOLDE AND NORMAN